U.S. patent application number 12/172748 was filed with the patent office on 2008-11-06 for method for abatement of allergens, pathogens and volatile organic compounds.
This patent application is currently assigned to Prompt Care, Inc.. Invention is credited to John Ross Cumberland, James L. Driver.
Application Number | 20080274012 12/172748 |
Document ID | / |
Family ID | 46123942 |
Filed Date | 2008-11-06 |
United States Patent
Application |
20080274012 |
Kind Code |
A1 |
Cumberland; John Ross ; et
al. |
November 6, 2008 |
METHOD FOR ABATEMENT OF ALLERGENS, PATHOGENS AND VOLATILE ORGANIC
COMPOUNDS
Abstract
The present invention pertains to methods utilizing ozone
treatment for abating allergens, pathogens, odors, and volatile
organic compounds. The methods can be employed to abate pollutants,
bacteria, viruses, mold, dander, funguses, dust mites, animal and
smoke odors, and the like. The methods employ specific combinations
of ozone concentration, hydrogen peroxide concentration,
temperature, and humidity delivered over a specified period of time
to achieve satisfactory abatement of the allergen, pathogen, odor,
or volatile organic compound.
Inventors: |
Cumberland; John Ross;
(Corona Del Mar, CA) ; Driver; James L.; (Irvine,
CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
Prompt Care, Inc.
Newport Beach
CA
|
Family ID: |
46123942 |
Appl. No.: |
12/172748 |
Filed: |
July 14, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11275192 |
Dec 16, 2005 |
7407624 |
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12172748 |
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10959822 |
Oct 6, 2004 |
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11275192 |
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PCT/US03/11800 |
Apr 14, 2003 |
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10959822 |
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60373738 |
Apr 16, 2002 |
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Current U.S.
Class: |
422/4 |
Current CPC
Class: |
A61L 2/10 20130101; A61L
9/22 20130101; F24F 2110/74 20180101; A61L 2/14 20130101; Y02B
30/70 20130101; A61L 9/20 20130101; A61L 9/015 20130101; F24F 6/00
20130101; F24F 3/16 20130101; F24F 2110/20 20180101; A61L 2/202
20130101; F24F 8/22 20210101; F24F 11/30 20180101; F24F 8/30
20210101; F24F 8/26 20210101; Y02A 50/20 20180101; F24F 8/192
20210101 |
Class at
Publication: |
422/4 |
International
Class: |
A61L 9/015 20060101
A61L009/015; A61L 9/20 20060101 A61L009/20 |
Claims
1. A method for abating a substance in a space, the method
comprising the steps of: sealing a space such that conditions of
ozone concentration, temperature, hydrogen peroxide concentration,
and relative humidity within the space can be controlled, wherein
the space contains at least one substance selected from the group
consisting of a pathogen, an allergen, and odor-causing agent;
maintaining an atmospheric ozone concentration in the space of at
least about 2 ppm; maintaining an atmospheric hydrogen peroxide
concentration in the space, wherein the atmospheric hydrogen
peroxide concentration is at least about 75% by weight of that of
the atmospheric ozone concentration; maintaining a relative
humidity within the space of at least about 50%; and maintaining a
temperature within the space of at least about 15.degree. C.;
wherein the steps are conducted substantially simultaneously for a
time period of at least about 0.5 hours, whereby the substance is
abated.
2. The method of claim 1, wherein the atmospheric ozone
concentration is from about 2 to about 10 parts per million.
3. The method of claim 1, wherein the relative humidity is from
about 50% to about 90%.
4. The method of claim 1, wherein the atmospheric hydrogen peroxide
concentration is from about 75% to about 150% by weight of the
atmospheric ozone concentration.
5. The method of claim 1, wherein the temperature is from about
15.degree. C. to about 27.degree. C.
6. The method of claim 1, wherein the time period is from about 0.5
hours to about 3 hours.
7. The method of claim 1 further comprising the step of: ceasing
providing ozone to the space; and thereafter exposing an interior
of the space to ultraviolet light, whereby an odor associated with
ozone is reduced.
8. The method of claim 1 further comprising the step of: ceasing
providing ozone to the space; and thereafter exposing the space to
a temperature above 27.degree. C., whereby an odor associated with
ozone is reduced.
9. The method of claim 1 further comprising the step of: providing
ions to the space, whereby an odor associated with ozone is
reduced.
10. The method of claim 1, wherein the space comprises an interior
portion of a building.
11. The method of claim 1, wherein the space comprises a room of a
building.
12. The method of claim 11, wherein the building comprises a
dwelling.
13. The method of claim 1, wherein the space comprises an interior
portion of a ship.
14. The method of claim 1, wherein the space comprises an interior
portion of passenger car.
15. The method of claim 1, wherein the space comprises an interior
portion a mobile home or a motor home.
16. The method of claim 1, wherein the pathogen is mold.
17. The method of claim 1, wherein the pathogen is selected from
the group consisting of Norwalk virus and anthrax.
18. The method of claim 1, wherein the allergen is selected from
the group consisting of dust mite feces, dander, tobacco smoke and
a protein capable of inducing an allergic reaction in a human
susceptible thereto.
19. The method of claim 1, wherein the odor-causing agent is a
volatile organic compound.
20. The method of claim 1, wherein the odor-causing agent is
urine.
21. A method for abating a substance in an enclosed space, the
method comprising the steps of: providing an ingress into the
space, wherein the space contains at least one substance selected
from the group consisting of a pathogen, an allergen, and
odor-causing agent; providing an egress out of the space; providing
ozone to an atmosphere within the space via the ingress, so as to
an atmospheric ozone concentration, as measured at the egress, of
at least about 2 ppm; providing hydrogen peroxide to an atmosphere
within the space via the ingress, so as to maintain an atmospheric
hydrogen peroxide concentration, as measured at the egress, that is
at least about 75% by weight of that of the atmospheric ozone
concentration; maintaining a relative humidity within the space of
at least about 70%; and maintaining a temperature within the space
of at least about 15.degree. C.; wherein the steps are conducted
substantially simultaneously for a time period of at least about
0.5 hours, whereby the substance is abated.
22. The method of claim 21, wherein the space is selected from an
interior of a wall in a building, an interior of a floor in a
building, and an interior of a ceiling in a building.
23. The method of claim 21, wherein the atmospheric ozone
concentration is from about 2 to about 10 parts per million.
24. The method of claim 21, wherein the atmospheric hydrogen
peroxide concentration is from about 75% to about 150% by weight of
the atmospheric ozone concentration
25. The method of claim 21, wherein the ingress and the egress are
situated on substantially opposite ends of the space.
26. The method of claim 21, wherein the pathogen is mold.
27. The method of claim 21, wherein the pathogen is selected from
the group consisting of Norwalk virus and anthrax.
28. The method of claim 21, wherein the allergen is selected from
the group consisting of dust mite feces, dander, tobacco smoke and
a protein capable of inducing an allergic reaction in a human
susceptible thereto.
29. The method of claim 21, wherein the odor-causing agent is a
volatile organic compound.
30. The method of claim 21, wherein the odor-causing agent is
urine.
31. The method of claim 21, wherein the space comprises an interior
portion of a building.
32. The method of claim 21, wherein the space comprises a room of a
building.
33. The method of claim 32, wherein the building comprises a
dwelling.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/275,192, filed Dec. 16, 2005, which is a
continuation-in-part of U.S. patent application Ser. No.
10/959,822, filed Oct. 6, 2004, which is a continuation, under 35
U.S.C. .sctn. 120, of International Patent Application No.
PCT/US03/11800, filed Apr. 14, 2003 under the Patent Cooperation
Treaty (PCT), which was published by the International Bureau in
English on Oct. 30, 2003, which designates the United States, and
which claims the benefit of U.S. Provisional Patent Application No.
60/373,738, filed Apr. 16, 2002, the disclosures of which are
hereby incorporated by reference in their entirety and are hereby
made a part of this specification.
FIELD OF THE INVENTION
[0002] The present invention pertains to methods utilizing ozone
treatment for abating allergens, pathogens, odors, and volatile
organic compounds. The methods can be employed to abate pollutants,
bacteria, viruses, mold, dander, funguses, dust mite allergens,
animal and smoke odors, and the like. The methods employ specific
combinations of ozone and hydrogen peroxide concentration,
temperature and humidity delivered over a specified period of time
to achieve satisfactory abatement of the allergen, pathogen, odor,
or volatile organic compound.
BACKGROUND OF THE INVENTION
[0003] Building-Related Illness (BRI) is a discrete, identifiable
disease or illness that can be traced to a specific pollutant or
source within a building. In contrast, the term Sick Building
Syndrome (SBS) is used to describe situations in which building
occupants experience acute health and comfort effects that appear
to be linked to time spent in a building, but no specific illness
or cause can be identified. Both syndromes are associated with
immediate or potential health problems and are of particular
concern as it is estimated that most people spend as much as 90% of
their time indoors. It is indoors where EPA studies have shown that
the levels of pollutants can be 2-5 times, and occasionally, more
than 100 times higher than outdoor levels.
[0004] The American Lung Association recently documented a decrease
in motivation, performance, and productivity among office workers
and school children in relation to poor indoor air quality within
buildings. Their evidence involving office workers suggests that
when individuals experience only two symptoms of discomfort, they
begin to perceive a reduction in their own performance. This
perception increases as the number of symptoms increases, averaging
3% loss with three symptoms, and an 8% loss with five symptoms.
[0005] The EPA stated in 1991, "The term "Sick Building Syndrome"
is used to describe situations in which building occupants
experience acute health and discomfort effects that appear to be
linked to time spent in a building, but no specific illness or
cause can be identified. The complaints can be localized in a
particular room or zone, or can be widespread throughout the
building. In contrast, the term "Building Related Illness" is used
when symptoms can be attributed directly to airborne building
contaminants." The EPA has just published a new reference document,
"Mold Remediation in Schools and Commercial Buildings" (EPA
402-K-01-001). This publication is the governmental standard for
mold and treatment of commercial buildings. The EPA states that
mold in commercial buildings contaminates or destroys everything it
grows on including building walls, air conditioning, ceiling and
carpeting, etc.
[0006] Identifying "Sick Buildings" can be difficult. Identifying
the actual cause of the `sickness` can be even more difficult.
Molds are a good example of the problems encountered when
attempting to identify the source of pollutants. They are present
everywhere, both indoors and outdoors. Their effects on people are
quite random, some experience extreme symptoms, while others have
only minor reactions.
[0007] Those who suffer from asthma, hay fever, or other allergies
are at a particularly high risk for Building-Related Illnesses.
Symptoms can include one or more of the following (ranging from
mild to acute): headache; eye, nose or throat irritation; dry or
itchy skin; dizziness and nausea; difficulty in concentrating;
fatigue; and sensitivity to odors. In the case of Building Related
Illnesses, the cause of the symptoms is not obvious, i.e., a cold
or flu. The symptoms can linger for several weeks or more. Most of
the affected people experience relief after leaving the building.
If inhabitants of a building experience these symptoms, then the
building's environment can be a factor.
[0008] Unhealthy indoor air associated with Sick Building Syndrome
and Building Related Illnesses can come from a variety of sources.
Most common are dust mites (and their feces), mold, off-gassing
chemicals (from carpets, paint, glues and plastics), and natural
sources (decaying plants or animals, radon, animals and their
dander, people). Many substances can infiltrate our indoor
airspaces and then accumulate to a point that leads to illness.
[0009] Molds (fungi) can often be associated with Sick Building
Syndrome and Building-Related Illnesses. According to an
Environmental Protection Agency (EPA) bulletin published in March
2001, "Molds can be found almost anywhere; they can grow on
virtually any organic substance, as long as moisture and oxygen are
present. There are molds that can grow on wood, paper, carpet,
foods, and insulation. When excessive moisture accumulates in
buildings or on building materials, mold growth will often occur,
particularly if the moisture problem remains undiscovered or
unaddressed."
[0010] Indoors and outdoors, mold is present everywhere. The term
mold applies to the microscopic members of the Fungi kingdom. It is
a fuzzy, cobweb-like growth produced on organic matter. Mold has no
ability to `fix` carbon using chlorophyll, so it relies on some
type of organic material as a food source. It can spread rapidly,
forming the mycelium (fungal body), which is made up of a fine
network of filaments (hyphae). The mycelium produces other clusters
of root like hyphae, called rhizoids, which penetrate the organic
material, secreting enzymes and absorbing water and the digested
sugars and starches. Other clusters of hyphae called
sporangiophores then reach upward, forming sporangia (knoblike
spore cases), which bear the particular color of the mold species.
Upon ripening, the sporangia break open and the windborne spores
land elsewhere to reproduce asexually. If they find themselves in a
less than ideal situation (not sufficient food, water, etc) molds
are likely to switch to a nonsexual method of reproduction (one not
involving swapping or combining of genetic material) for the
duration. This can make molds hard to identify, since species are
classified by their sexual characteristics (e.g., kind of spore
cell wall, spore-producing cells, and sacs that store cells).
Worldwide there are more than 100,000 species of mold, with at
least 1,000 species common in the United States. Some of the most
commonly found are species of Cladosporium, Penicillium, and
Aspergillus. Mold can be found almost everywhere and it can grow on
virtually any organic substance. Mold is most likely to grow where
there is water or dampness, such as bathrooms, attics, and
basements.
[0011] Most types of mold commonly encountered are not hazardous to
healthy individuals. However, there are some that have achieved
recent notoriety that are strongly toxic such as Stachybotrys.
Stachybotrys is not common but can be very harmful when encountered
in quantity. Others, like Aspergillus, can be dangerous as well.
Aspergillosis is a lung disease suffered generally by
immune-compromised people. In this disease, the Aspergillus mold
actually grows in a person's lungs and can cause death. In general,
too much exposure to even common molds can cause or worsen
conditions such as asthma, hay fever, or other allergies. Common
symptoms of overexposure to mold are cough, congestion, runny nose,
eye irritation, and aggravation of asthma. More serious health
effects, such as fevers and breathing problems, can occur depending
on the amount of exposure and person's individual
vulnerability.
[0012] When moldy material becomes damaged or disturbed, spores
(reproductive bodies similar to seeds) can be released into the
air. Exposure can occur if people inhale the spores, directly
handle moldy materials, or accidentally ingest it. Mold can
sometimes produce chemicals called Mycotoxins, which can also cause
illness to sensitive people.
[0013] All molds must have water to grow. Mold can grow almost
anywhere there is water damage, high humidity, or dampness.
Removing the source of moisture is critical to preventing mold
growth. Typical water sources utilized by mold in residential
environments include air conditioner condensers, roof leaks, pipe
leaks, sprinklers adjacent to an outside wall, and the like.
[0014] Stachybotrys Chartarlm (also known as Stachybotrys atra) is
a type of mold that has been associated with health effects in
people. It is a greenish-black mold that can grow on materials with
a high cellulose content, such as drywall, hanging ceilings and
wood--that has been chronically moist or water damaged, due to
excessive humidity, water leaks, condensation, or flooding.
Numerous molds are black in appearance, but are not Stachybotrys.
For example, the black mold commonly found between bathroom tiles
is not Stachybotrys. Stachybotrys can only be positively identified
via laboratory testing.
[0015] Indoor levels of Stachybotrys are typically low; however, as
with other types of mold, at higher concentrations health effects
can occur. These include allergic rhinitis (cold-like symptoms),
dermatitis (rashes), sinusitis, conjunctivitis, and aggravation of
asthma. Some related symptoms are general, such as inability to
concentrate and fatigue. Usually, symptoms disappear after the
contamination is removed.
[0016] There has been some evidence linking Stachybotrys with
pulmonary hemosiderosis in infants who are generally less than six
months old. Pulmonary hemosiderosis is an uncommon condition that
results from bleeding in the lungs. In studies of pulmonary
hemosiderosis, the exposure to Stachybotrys came from highly
contaminated homes, where infants were continually exposed over a
long period of time. Individuals exposed to the mold who exhibit
symptoms characteristic of mold exposure should seek appropriate
medical attention.
[0017] Visible mold can be sampled and analyzed by laboratories
specializing in microbiology. However, these tests can be
expensive--from hundreds to thousands of dollars. Even if a
building is tested for mold, it is difficult to determine at what
levels health effects can possibly occur. Therefore, it is
important to attack any mold infestation. For small infestations,
bleach and water can be effective to kill the mold growth. For
larger infestations, more extensive treatment wherein large areas
of a building or the whole building are treated can be necessary to
kill all of the mold. Once the mold is destroyed, the next step is
to find the mold's source of water. Mold will not grow without
water, so to prevent its return, its source of water must be
located and eliminated. In order to adequately remediate a mold
infestation, it is necessary to both destroy the mold and to
eliminate the mold's source of water.
[0018] While mold infestation itself is not becoming more common,
knowledge of it and the problems it can cause is becoming more
widely disseminated. In the last few years there have been many
widely publicized cases concerning sicknesses caused by mold and
the multi-million dollar settlements awarded to those who suffered
the consequences of mold toxicity. As well, there have been reports
of individuals who have burned their houses down because that was a
cheaper solution than remediation of the mold-caused damage.
Removal of moldy materials can involve procedures similar to those
associated with removal of toxic waste material, such as asbestos,
which means that any remediation can be extremely expensive to
conduct. It is because of all this publicity that there is an
appearance that mold has become more prevalent when in fact it has
only become more recognized for its undesirable qualities.
[0019] Other pathogens, allergens, and odor-causing agents, e.g.,
dust mite feces, fungi, spores, pollen, mildew, bacteria, viruses,
amoebas, fragments of plant materials, human and animal dander,
proteins that that cause allergic reaction such as the ones in dust
mite feces and animal dander, feather dust, litter dust, tobacco
smoke, smoke from fires, volatile organic compounds, and other
bio-aerosols and inorganic aerosols and gases, can also be the
cause of Building Related Illnesses. For example, the feces of
household dust mites can cause allergic reactions. A gram of house
dust (approximately half of a teaspoon) can contain as many as
1,000 dust mites. That same amount of dust could hold over 250,000
of their fecal pellets. Once airborne, dried dust mite droppings
are so small that they are easily inhaled causing allergic
reactions in many people. These reactions can range from sneezing,
coughing, itchy eyes and sniffles to asthma, eczema, even snoring.
House dust mites are related to spiders. They are eight legged
creatures invisible to the human eye. They survive by eating dead
skin cells. A dust mite will produce 20 fecal pellets per day,
which is 200 times its own body weight, during its short lifetime.
The greatest number of dust mites in the home is usually found in
the bedroom, specifically in the bedding and pillow. The skin and
moisture shed each night provide ideal conditions for their growth.
Millions of mites can be present in bedding, and up to 10% of a
two-year-old pillow's weight can be made up of house dust mites and
their droppings.
[0020] Pets are another source of allergens. Household pets are the
most common source of allergic reactions to children. It is
estimated that 10 million animal owners may be allergic to their
animals, and 20% to 30% of the people who have asthma are also
allergic to animals. Many people react to animal allergies in
extremely different manners. For some people, animal odors, dander,
saliva, and urine can cause allergic reactions. Animal fur can also
collect outdoor pollens, mold spores, and other outdoor allergens
that are then brought indoors. A recent study reviewed by the
American Academy of Allergy, Asthma and Immunology, indicated that
approximately 80% of the animal owners surveyed keep their animals
indoors most of the time. These findings may help explain why
allergy symptoms, such as itchy and watery eyes, sneezing,
coughing, wheezing and hives in allergic children and adults,
worsen with continued exposure to animals.
[0021] The American Lung Association's "Health House Project"
stated that "[.alpha.]ccording to a recent study published in
Pediatrics magazine, asthma cases could drop nearly 40% among
America children under age 6 if susceptible youngsters did not have
pets or other allergy triggers in their home. The study also found
that children with animal allergies were 24 times more likely to
have asthma than those without such allergies."
[0022] One of the more difficult problems with allergies to animals
is it can take two years or more to develop in a home and may not
subside until 6 months or more after the animal has been removed
from the home. Carpeting and furniture can act as reservoirs for
animal dander and allergens. The animal dander can become a food
source for common household dust mites. These pest and allergens
can also find their way throughout the homes' heating and air
condition system.
[0023] The elderly, young children and infants in particular, are
especially susceptible to negative reactions to allergens and
pathogens. Many magazines, such as Harper's Bazaar and Parent's
have articles on how to clean and prepare a home for a new infant.
Harper's has a Wellness Report that contains a home purity
checklist that cites mold, dust mites, and animal dander as major
home health concerns. As mentioned above, of major concern to
infants is animal dander that can trigger sniffling, stuffy noses,
and sneezing and water eyes. Dust mites are a known trigger for
asthma, and found everywhere.
[0024] Of serious concern to infants is mold, which comes from
persistent leaks from air conditioners and plumbing that can lead
to airborne mold, which aggravates allergies. Some indoor molds
have the potential to produce extremely potent toxins called
Mycotoxins. Mycotoxins are readily absorbed by the intestinal
lining, airways, and skin. Molds that produce potent toxins have
been associated with acute pulmonary hemorrhage among 37 infants
from the Cleveland, Ohio, area between 1993 and 1998. Twelve of
these children died. As stated by Dr. Henry Fishman M.D. P.C.,
Diplomat American Board of Allergy and Immunology, American Board
of Internal Medicine and National Board of Medical Examiners,
"There is a body of evidence that indoor allergies, particularly
dust mites, may cause asthma in some infants. Without the dust mite
sensitivity, asthma does not develop. Untreated asthma in pregnant
women can lead to early deliveries, miscarriages, and low birth
weight infants. Indoor allergens can make this worse. Also
allergies can lead to infections. Kids' immune systems cannot
handle the infections burden as well as an adult. So kids with
allergies have trouble with infections which can bother their tiny
lungs. In other words, in some sensitive kids, allergies have a
huge impact on their nose, sinuses and lungs."
[0025] Commercial buildings often present special concerns
regarding Sick Building Syndrome, Building Related Illnesses.
According to Business Week Magazine, today's business office is
home to as many as 30 different volatile organic chemicals released
by building materials, furnishing and office equipment. Some of the
biggest offenders are sealed windows, carpets and padding,
carcinogenic cleaning products, the office restroom, cafeterias and
kitchen areas, and building renovations. Many people work in
enclosed building or offices. Not being able to open windows means
you do not always have enough fresh air to circulate within the
building. Many carpets, rugs, and paddings are made in part from
petrochemicals. An example is formaldehyde odor which is often
noticed for a few weeks after new carpet is installed. The same is
true with products used in the interiors of new cars. The odor
being released is called "out gassing." It often affects people
with allergies or sensitive skin. There are over 70,000 identified
chemical cleaning products on the market that are used to clean
buildings and offices. Some of them contain toxic solvents that, it
is claimed, are considered safe when used properly. Clogged toilets
and flooded restrooms can create toxic mold and airborne mold
spores in area that are difficult to continually inspect. Many
buildings have common lunch and food areas that must be maintained
within local Health Department standards. Office construction and
remodeling can cause mold to spread throughout a building in the
matter of a few minutes according to EPA testing. Mold and
contaminated dust can cause employees serious health problems.
[0026] Problems associated with Sick Building Syndrome have been
extensively reported in the media. Media coverage has shown
buildings being condemned; structures being burned down to destroy
toxic and mold contaminates. Business and consumer magazines such
as Business Week, Time, The Wall Street Journal, Reader's Digest
and People Magazine are reporting insurance claims cases and
medical awards to people that have been harmed by these toxic
conditions. In every case, the courts decisions held that the
condition could and should have been treat earlier by the building
owners or insurance companies. Television networks are giving
coverage to this problem as a major health and business issue.
[0027] Erin Brockovich, antipollution crusader, was featured on CBS
News broadcast "48 Hours," because her home is infested with the
toxic stachybotrys mold. NBC Nightly News coverage of the Melinda
Ballard's toxic infestation case stated "A Texas jury decided her
insurer committed fraud and mishandled her claim, awarding her $32
million."
[0028] In the August, 2000 issue of Claims Magazine, an insurance
industry publication, "a jury recently awarded more than $40
million in personal injury claims. There were over 200 workers'
compensation claims and at least 180 separate lawsuits. Previously,
such lofty figures were seen only in asbestos or drug-related class
actions. Now, we are starting to hear 11-digit figures mentioned in
litigation concerning the lowly mold fungi."
[0029] The Lawyers Weekly USA, a national publication, stated in
their October 6, 2000 edition, that claims for personal injury and
property damage caused by mold growing inside buildings are on the
rise, and one of the "hottest areas" in construction defect and
toxic tort law.
[0030] The United Press International reports in a feature story
titled "Toxic mold a growing legal issue" that, "Mold contamination
claims were virtually unheard of a few years ago, but people are
becoming more aware of indoor air quality issues because of the
expanding scientific and medical knowledge of the toxic effects of
mold.
SUMMARY OF THE INVENTION
[0031] A method for abating or remediating pathogens or allergens
in a commercial or residential setting that ensures the elimination
of the maximum number of chemical pollutants, bacteria, viruses,
mold, allergens and other fungi, as well as urine and smoke odors
possible within the treated area is therefore desirable. It is also
desirable that the method leaves no residual chemicals behind, only
a fresh, clean smell. A method that may be conducted by trained
technicians in a safe and time effective manner, and may preferably
be completed at a time when the premises is likely to be vacated
(working/school hours for a home, evening hours for an
office/commercial location), allowing minimal disruption to a
company's or family's daily routine is desirable as well.
Particularly desirable is a method that is capable of treating both
small as well as large interior areas, and multi-floor or separate
locations, as well as major infestations of various types of molds,
including toxic molds, without the need for hazardous material
precautions, is also desirable. The process of abating can include,
but is not limited to, killing, destroying, neutralizing, lessening
the strength or effectiveness of, converting, or otherwise reducing
the harmful or undesirable effects of the pathogen, allergen,
volatile organic compound, or other substance.
[0032] It is noted that tabletop and room unit ozone generators are
marketed to the consumer as means of improving indoor air quality.
Consumer Reports (1992), the National Institute of Occupational
Safety and Health (NIOSH) (Boeniger, 1995), and the U.S. EPA (1995)
concluded that tabletop and room unit ozone generators are not
effective in improving indoor air quality. A recent study by the
U.S. EPA concluded that ozone is not effective for killing airborne
molds and fungi even at high concentrations (6-9 ppm) (U.S. EPA,
1995). In contrast to this earlier work, it has been determined
that selected conditions of ozone concentration, hydrogen peroxide,
humidity, and temperature are highly effective at killing airborne
molds and fungi at even lower ozone concentrations.
[0033] Although mold abatement is primarily referred to in regard
to the preferred embodiments, it is to be understood that the
methods described are suitable for use in abating other substances,
including, but not limited to, pathogens, allergens, and odors,
including, but not limited to, dust mite allergens, other fungi,
spores, pollen, mildew, bacteria, viruses, amoebas, fragments of
plant materials, human and animal dander, feather dust, litter
dust, tobacco smoke, volatile organic compounds, and other
bioaerosols and inorganic aerosols and gases.
[0034] In preferred embodiments, ozone (commonly referred to as
activated oxygen) in combination with hydrogen peroxide is used in
the abatement process. Ozone is one of the most powerful sanitizers
and deodorizers known. Ozone is a natural component of ambient air.
The highest levels of naturally occurring ozone are found in
forests, mountains and along seashores. Ozone is created when the
energy from ultra violet light or an electrical discharge changes
the oxygen molecules (O.sub.2) into ozone (O.sub.3). This ozone
molecule is highly unstable and readily reverts back to O.sub.2.
When it does revert back to O.sub.2 the extra oxygen atom that it
releases may react with another compound (for example a malodorous
compound, or the surface of an allergen, germ, or mold) changing
that compound or microorganism in the process.
[0035] Alternatively the extra atom of oxygen may react with a
molecule of water (H.sub.2O) to produce a `hydroxyl radical`
(--OH). Hydroxyl radicals have been demonstrated to be highly
destructive to other molecules containing carbon or sulfur bonds
(single or double). In fact the hydroxyl molecule is significantly
more reactive than ozone. In air, the number of hydroxyls produced
by the decomposition of ozone is highly dependent on the amount of
water vapor present (humidity). In general, the higher the
humidity, the larger the number of hydroxyls produced and the more
reactive the air, ozone, hydroxyl mixture becomes.
[0036] The number of hydroxyls produced by ozone can be
significantly increased if the air contains the chemical hydrogen
peroxide (H.sub.2O.sub.2). Hydrogen peroxide rapidly decomposes
into hydroxyl radicals when attacked by ozone. In the preferred
embodiment, hydrogen peroxide is added to an ultrasonic humidifier
used to provide and control humidity in the treated areas. Given
sufficient ozone, and an abundance of airborne hydrogen peroxide
over a short period of time, enough oxygen atoms and hydroxyl
radicals are produced to effectively convert the polluting or
otherwise undesirable substances present into new and typically
less contaminating or harmful ones.
[0037] Bacteria, fungi (molds and mildew) which can cause
unpleasant odors, allergic reactions and sometimes disease, are
destroyed when they come into contact with ozone and/or the
hydroxyl radical. As with chemical pollutants, the outer membranes
or shells of these microorganisms contain receptors that
ozone/hydroxyl attacks and, if sufficient ozone/hydroxyl is
present, break down. Without its protective membrane or shell, the
microorganism dies quickly.
[0038] The methods of preferred embodiments utilize the chemical
characteristics of ozone and hydrogen peroxide to generate a highly
effective natural sanitizer while ensuring the proper protection
for building occupants and technicians administering the treatment.
The end result is a highly purified space with cleaned air
containing oxygen as a residual substance generated by the
process.
[0039] In a first aspect, a method for abating a substance is
provided, the method comprising the step of: exposing a substance
selected from the group consisting of a pathogen, an allergen, and
an odor-causing agent to a gaseous atmosphere comprising water
vapor, ozone, and hydrogen peroxide, wherein the atmosphere has an
ozone concentration of from about 2 to about 10 parts per million,
a relative humidity of from about 50% to about 90%, a hydrogen
peroxide concentration that is from about 75% to about 150% by
weight of the ozone concentration, and a temperature of from about
15.degree. C. to about 27.degree. C., wherein the substance is
exposed to the atmosphere for a time period of from about 0.5 hours
to about 3 hours, whereby the substance is abated.
[0040] In an embodiment of the first aspect, the pathogen is
selected from the group consisting of mold, Norwalk virus, and
anthrax.
[0041] In an embodiment of the first aspect, the allergen is
selected from the group consisting of dust mite feces, dander,
tobacco smoke, and a protein capable of inducing an allergic
reaction in a human susceptible thereto.
[0042] In an embodiment of the first aspect, the odor-causing agent
is selected from the group consisting of a volatile organic
compound and urine.
[0043] In a second aspect, a method for abating a substance in an
space is provided, the method comprising the steps of: sealing a
space such that conditions of ozone concentration, temperature,
hydrogen peroxide concentration, and relative humidity within the
space can be controlled, wherein the space contains at least one
substance selected from the group consisting of a pathogen, an
allergen, and odor-causing agent; maintaining an atmospheric ozone
concentration in the space of at least about 2 ppm; maintaining an
atmospheric hydrogen peroxide concentration in the space, wherein
the atmospheric hydrogen peroxide concentration is at least about
75% by weight of that of the atmospheric ozone concentration;
maintaining a relative humidity within the space of at least about
50%; and maintaining a temperature within the space of at least
about 15.degree. C.; wherein the steps are conducted substantially
simultaneously for a time period of at least about 0.5 hours,
whereby the substance is abated.
[0044] In an embodiment of the second aspect, the atmospheric ozone
concentration is from about 2 to about 10 parts per million, the
relative humidity is from about 50% to about 90%, the atmospheric
hydrogen peroxide concentration is from about 75% to about 150% by
weight of the atmospheric ozone concentration, the temperature is
from about 15.degree. C. to about 27.degree. C., and the time
period is from about 0.5 hours to about 3 hours.
[0045] In an embodiment of the second aspect, the method further
comprises the step of ceasing providing ozone to the space; and
thereafter exposing an interior of the space to ultraviolet light,
whereby an odor associated with ozone is reduced.
[0046] In an embodiment of the second aspect, the method further
comprises the step of ceasing providing ozone to the space; and
thereafter exposing the space to a temperature above 27.degree. C.,
whereby an odor associated with ozone is reduced.
[0047] In an embodiment of the second aspect, the method further
comprises the step of providing ions to the space, whereby an odor
associated with ozone is reduced.
[0048] In an embodiment of the second aspect, the space comprises
an interior portion of a building.
[0049] In an embodiment of the second aspect, the space comprises a
room of a building.
[0050] In an embodiment of the second aspect, the building
comprises a dwelling.
[0051] In an embodiment of the second aspect, the space comprises
an interior portion of a ship.
[0052] In an embodiment of the second aspect, the space comprises
an interior portion of passenger car.
[0053] In an embodiment of the second aspect, the space comprises
an interior portion a mobile home or a motor home.
[0054] In a third aspect, a method for abating a substance in an
enclosed space is provided, the method comprising the steps of:
providing an ingress into the space, wherein the space contains at
least one substance selected from the group consisting of a
pathogen, an allergen, and odor-causing agent; providing an egress
out of the space; providing ozone to an atmosphere within the space
via the ingress, so as to an atmospheric ozone concentration, as
measured at the egress, of at least about 2 ppm; providing hydrogen
peroxide to an atmosphere within the space via the ingress, so as
to maintain an atmospheric hydrogen peroxide concentration, as
measured at the egress, that is at least about 75% by weight of
that of the atmospheric ozone concentration; maintaining a relative
humidity within the space of at least about 70%; and maintaining a
temperature within the space of at least about 15.degree. C.;
wherein the steps are conducted substantially simultaneously for a
time period of at least about 0.5 hours, whereby the substance is
abated.
[0055] In an embodiment of the third aspect, the space is selected
from an interior of a wall in a building, an interior of a floor in
a building, and an interior of a ceiling in a building.
[0056] In an embodiment of the third aspect, the atmospheric ozone
concentration is from about 2 to about 10 parts per million.
[0057] In an embodiment of the third aspect, the atmospheric
hydrogen peroxide concentration is from about 75% to about 150% by
weight of the atmospheric ozone concentration
[0058] In an embodiment of the third aspect, the time period is
from about 0.5 hours to about 3 hours.
[0059] In an embodiment of the third aspect, the ingress and the
egress are situated on substantially opposite ends of the
space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] FIG. 1 provides a schematic of an ozone generator and
ultrasonic humidifier system capable of delivering ozone at a rate
of 60 g/hour.
[0061] FIG. 2 provides levels (spores/m.sup.3) of cladosporium
spores, ascospores, basidiospores, periconia/myxomycetes,
penicillium/aspergillus, algae, ganodera basidiospores, and
alternaria spores in the air in a dining room of a Santa Monica,
Calif. home before and after treatment, and outdoors.
[0062] FIG. 3 provides levels (spores/m.sup.3) of cladosporium
spores, ascospores, basidiospores, periconia/myxomycetes,
penicillium/aspergillus, algae, ganodera basidiospores, and
alternaria spores in the air in a master bedroom of a Santa Monica,
Calif. home before and after treatment, and outdoors.
[0063] FIG. 4 provides levels (spores/m.sup.3) of cladosporium
spores, ascospores, basidiospores, periconia/myxomycetes,
penicillium/aspergillus, algae, ganodera basidiospores, and
alternaria spores in the air in a second bedroom of a Santa Monica,
Calif. home before and after treatment, and outdoors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0064] The following description and examples illustrate a
preferred embodiment of the present invention in detail. Those of
skill in the art will recognize that there are numerous variations
and modifications of this invention that are encompassed by its
scope. Accordingly, the description of a preferred embodiment
should not be deemed to limit the scope of the present
invention.
[0065] The processes of preferred embodiments use high
concentrations of ozone. The process involves optimizing treatment
conditions by employing a relationship between ozone concentration,
humidity, hydrogen peroxide concentration, temperature, duration of
treatment, volume of space, and condition being treated. This
relationship, termed the `target dosage` calculation, has been
determined by laboratory experimentation and field testing. By
utilizing these target dosages to apply a prescribed concentration
of ozone and hydrogen peroxide for a prescribed period of time in a
controlled area, the elimination of most odors, bacteria, viruses,
and molds can be achieved. When the treatment is completed, the
ozone generators and humidifiers are removed from the treated area
and fans are employed to replace the ozonated air with fresh
outside air through just-opened doors and windows. Alternatively
the ozone and hydrogen peroxide is left in the space to naturally
decompose back to oxygen and water. The half life of ozone is
approximately 30 minutes under the conditions employed in this
embodiment while the half life of hydrogen peroxide is measured in
seconds or minutes when in the presence of ozone. The ozone is
thereby returned to a level that is no higher than the outdoor
ambient level and the hydrogen peroxide is eliminated completely,
resulting in an improvement in indoor air quality.
[0066] Ozone has a long history of use in purification methods. The
Food and Drug Administration approved ozone for use in food
preservation in June 2001. Currently ozone is used to purify most
of the tap and bottled water in the US as well as such other
diverse tasks as keeping fruits and vegetables fresh during
storage. Low powered ozone generators have been available for many
years for in-home use; however these units have proven to be very
problematic. The units that are safe to operate with people present
generate levels of ozone that are too low to be effective in
abating mold and other pathogens and allergens. The more powerful
units that are effective in decontaminating a room or house
generate levels of ozone that are unsafe for continuous
occupation.
[0067] The concentrations of ozone used in the methods of preferred
embodiments can cause lung irritation, so exposure during treatment
is avoided. During the process, all animals and people remain
outside the area being treated. However, in less than an hour
following a treatment, the ozone levels in the area treated can be
reduced to that of the outside air and no harmful residual
substances are left behind.
[0068] The hydroxyl radical, which can be the result of an ozone
molecule (O.sub.3) interacting with a water molecule (humidity in
the air), has been found to be significantly more reactive than
direct oxidation by the ozone molecule. However the amount of
hydroxyl radicals formed in a mixture of ozone and humidified air
is relatively small and is highly dependent on the amount of
humidity present. The addition of hydrogen peroxide
(H.sub.2O.sub.2) to the air greatly increases the hydroxyls formed
and therefore greatly increases the speed and efficacy of the
methods of preferred embodiments. The hydrogen peroxide reacts with
the ozone, converting the ozone and hydrogen peroxide molecules to
the more highly oxidative hydroxyl radicals (OH). The resultant
mixture then has two methods of eliminating the various
contaminants, direct oxidation by the ozone, and indirect oxidation
through the action of the hydroxyl radicals. These oxidation
reactions compete for contaminants to oxidize. The ratio of direct
oxidation with molecular ozone is relatively slow
(10.sup.5-10.sup.7 M.sup.-1 sec.sup.-1) compared to hydroxyl
radical oxidation (10.sup.12-10.sup.14 M.sup.-1 sec.sup.-1). In
order to maintain the ratio of hydroxyls to ozone as high as
possible, hydrogen peroxide is preferably continuously introduced
into the area being decontaminated via the ultrasonic humidifier.
This ensures the highest concentration of hydroxyl radicals for the
entire duration of the preferred embodiment. However, in certain
embodiments it can be acceptable to introduce hydrogen peroxide
intermittently, or in only a single dose.
[0069] The process of the preferred embodiments kills mold it comes
into contact with. However, mold that is inside of walls or in
other areas not accessible to freely circulating air can
necessitate special steps in order to ensure all of the mold is
killed.
[0070] There is no way to determine how long a treated premises
will remain contaminant free. Mold can be effectively abated by the
methods of preferred embodiments. However, if the mold's supply of
water is not removed the mold can return. Similar principles apply
to other contaminants. As long as they are kept from reentering,
the premises remains contaminant free.
[0071] While living things, such as people, animals, and sensitive
plants are removed from the premises while the house is being
treated, the process does not harm anything else, e.g., exposed
surfaces such as textiles, carpets, paper, paint, and the like, or
household goods such as furnishings or electronics. The treatment
does not leave behind a film or residue of any kind, only a clean,
fresh interior environment.
[0072] Odor-causing agents, e.g., fish, curry, garlic, onion and
other stubborn cooking odors, along with smoking and animal odors
are easily neutralized or removed from the air, as well as from
furniture, bedding, and carpets, by the methods of preferred
embodiments. Note that animal smells originating from places where
the animal has heavily urinated are not easily cleaned due to the
concentration of urine present. It is preferred to pre-treat such
stubborn areas with an enzymatic cleaner prior to treatment
according to the preferred embodiments.
[0073] The methods of preferred embodiments have the major
advantage of not requiring tenting of the house, or extreme
measures to seal off egresses. The methods are also quick.
Typically, five hours is sufficient to treat a typical indoor space
of 25,000 cu. ft. or less. An average treatment typically takes
five hours to complete, one hour to set up equipment, 3 hours for
treatment, and another hour for equipment removal, venting of
ozone-containing air, and post treatment evaluation of the
premises. However treatments can last from seconds to minutes,
hours, or even days, depending on the target dosage.
[0074] The method is effective in removing odors associated with
volatile organic compounds. However, as noted above, if the source
of the odor is not eliminated, the odor can return.
[0075] While the method of preferred embodiments is especially
preferred for abating mold in residential and commercial buildings,
it is also effective in treating other structures, such as boats.
Surface mold and fuel odors can be eliminated, along with
unpleasant aromas from the bilge and head. The process is
particularly successful in taking out the musty smells in motor
homes that have been closed up for the season or ones that are
experiencing fuel smells or cooking odors. Any closed area or
structure that is affected by pathogens, allergens, or undesirable
odors can be amenable to treatment according to methods of the
preferred embodiments, including cars, trucks, passenger buses,
aircraft, train cars, and the like.
[0076] It is often preferred to treat a premises according to the
methods of preferred embodiments on a regular basis, e.g., monthly,
quarterly, semi-annually, or the like, so as to maintain a
satisfactory air quality level in the premises and avoid recurrence
of mold infestations and the buildup of other allergens such as
dust mite feces and pet dander.
Abated Substances
[0077] Methods of preferred embodiments can be employed to abate
any of the substances discussed herein, but the methods are
particularly preferred for pathogens, molds, allergens, and
Volatile Organic Compounds (VOCs).
[0078] Pathogens that can be controlled by methods of preferred
embodiments include, but are not limited to Anthrax (Bacillus
anthracis); Botulism (Clostridium botulinum toxin); Brucella
species (brucellosis); Brucellosis (Brucella species); Burkholderia
mallei (glanders); Burkholderia pseudomallei (melioidosis);
Chlamydia psittaci (psittacosis); Cholera (Vibrio cholerae);
Clostridium botulinum toxin (botulism); Clostridium perfringens
(Epsilon toxin); Coxiella burnetii (Q fever); E. coli O157:H7
(Escherichia coli); Emerging infectious diseases such as Nipah
virus and hantavirus; Norwalk virus; Severe Acute Respiratory
Syndrome (SARS); Acquired Immune Deficiency Syndrome (AIDS) virus;
Human Immunodeficiency Virus (HIV); Epsilon toxin of Clostridium
perfringens; Escherichia coli O157:H7 (E. coli); Food safety
threats (e.g., Salmonella species, Escherichia coli O157:H7,
Shigella); Francisella tularensis (tularemia); Glanders
(Burkholderia mallei); Melioidosis (Burkholderia pseudomallei);
Plague (Yersinia pestis); Psittacosis (Chlamydia psittaci); Q fever
(Coxiella burnetii); Ricin toxin from Ricinus communis (castor
beans); Rickettsia prowazekii (typhus fever); Salmonella species
(salmonellosis); Salmonella Typhi (typhoid fever); Salmonellosis
(Salmonella species); Shigella (shigellosis); Shigellosis
(Shigella); Smallpox (variola major); Staphylococcal enterotoxin B;
Tularemia (Francisella tularensis); Typhoid fever (Salmonella
Typhi); Typhus fever (Rickettsia prowazekii); Variola major
(smallpox); Vibrio cholerae (cholera); Viral encephalitis
(alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine
encephalitis, western equine encephalitis]); Viral hemorrhagic
fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g.,
Lassa, Machupo]); Water safety threats (e.g., Vibrio cholerae,
Cryptosporidium parvum); and Yersinia pestis (plague).
[0079] Common household molds that can be remediated by methods of
preferred embodiments include, but are not limited to Acremonium;
Alternaria; Aspergillus fumigatus; Aspergillus niger; Aspergillus
species Var. 1; Aspergillus species Var. 2; Aureobasidium;
Bipolaris; Chaetomium; Cladosporium; Curvularia; Epicoccum;
Fusarium; Geotrichum; Memnoniella; Mucor; Mycelia sterilia;
Nigrospora; Paecilomyces; Penicillium species Var. 1; Penicillium
species Var. 2; Pithomyces; Rhizopus; Sporothrix; Sporotrichum;
Stachybotrys; Syncephalastrum; Trichoderma; and Yeast. Molds need
high humidity levels and a surface on which to grow. Common areas
for mold growth are garbage containers, food storage areas,
upholstery, and wallpaper. Molds also commonly grow in damp areas
such as basements, shower curtains, window moldings, and window air
conditioners.
[0080] Indoor allergens that can be remediated by methods of
preferred embodiments include dust mite feces. Dust mite feces are
the major source of allergic reaction to household dust. The mites
thrive on shed human skin and are most commonly found in bedrooms,
where skin cells are abundant. Preventive measures include
frequently laundering bed linens in hot water and removing carpets
from the room. In some cases, homeowners might have to encase the
bed mattress, box springs, and pillows in vinyl covers. Other
allergens of animal origin include skin scales shed from humans and
animals. Commonly called dander, these are another major allergen.
Dander from such animals as cats, dogs, horses, and cows can infest
a home even if the animal has never been inside. Rodent urine from
mice, rats, and guinea pigs is another allergen. Cockroach-derived
allergens come from the insect's discarded skins. As the skins
disintegrate over time, they become airborne and are inhaled.
[0081] Tobacco smoke, engine exhaust, and similar allergens and
odors or odor-causing agents can be abated by methods of preferred
embodiments, as can volatile organic compounds from sources such as
household products including paints, carpets, paint strippers, and
other solvents; wood preservatives; aerosol sprays; cleansers and
disinfectants; moth repellents and air fresheners; stored fuels and
automotive products; hobby supplies; dry-cleaned clothing, and the
like. VOCs include organic solvents, certain paint additives,
aerosol spray can propellants, fuels (such as gasoline, and
kerosene), petroleum distillates, dry cleaning products, and many
other industrial and consumer products ranging from office supplies
to building materials. VOCs are also naturally emitted by a number
of plants and trees. Some of the more common VOCs include ammonia,
ethyl acetate, methyl propyl ketone, acetic acid, ethyl alcohol,
methylene chloride, acetone, ethyl chloride, n-propyl chloride,
acetylene, ethyl cyanide, nitroethane, amyl alcohol, ethyl formate,
nitromethane, benzene, ethyl propionate, pentylamine, butane,
ethylene, pentylene, butyl alcohol, ethylene oxide, propane, butyl
formate, formaldehyde, propionaldehyde, butylamine, formic acid,
propyl alcohol, butylene, heptane, isopropyl chloride, carbon
tetrachloride, hexane, propyl cyanide, chlorobenzene, isobutane,
propyl formate, carbon monoxide, hexyl alcohol, propylamine,
chlorocyclohexane, hydrogen gas, propylene, chloroform, hydrogen
sulfide, tertiary butyl alcohol, cyclohexane, isopropyl acetate,
tetrachloroethylene, cylohexene, methane, toluene,
1-dichloroethane, methyl alcohol, 1,1,2-trichloroethane,
1,2-dichloroethane, methyl chloride, trichlorethylene, diethyl
ketone, methyl chloroform, triethylamine, diethylamine, methyl
cyanide, xylene, ethane, and methyl ethyl ketone.
[0082] Odors and odor-causing substances that can be abated include
skunk odors, urine, pet odors, and the like.
[0083] It is generally preferred to subject the substance to be
abated or remediated to ozone at the preferred concentrations in
the atmosphere as discussed below, generally 2 to 10 ppm, and
adjust the length of treatment as necessary to ensure satisfactory
kill and/or neutralization levels. Serious mold infestations are
generally the most resistant substance to remediate. Treatment
times of 1, 2, 3, 4, 5, 6, 12, 24, or 48 hours or more can be
employed to ensure penetration of the ozone/hydroxyl mixture
throughout the entire mass of a serious infestation and achieve a
100% kill and neutralization. However should it be difficult to
have the contaminated premises vacated for these long periods of
time, it may be necessary to leave the treatment time at the
preferred treatment time (2 to 4 hours) while at the same time
increasing the level of ozone and/or hydrogen peroxide. Ozone
levels of 20, 30, 40, 50, 100, 200, 400 or more ppm can be
desirable along with a proportionate increase of hydrogen peroxide
to such that the concentration (by weight) of hydrogen peroxide in
the atmosphere is up to about 150% or more of that of ozone in the
atmosphere introduced into the area to be treated, preferably from
about 75% to about 150%, more preferably from about 85% to about
125%, and even more preferably from about 90% to about 100%.
However, in certain embodiments it can be desirable to provide even
higher concentrations of ozone.
[0084] A treatment time of 2 to 3 hours in the methods of preferred
embodiments is generally effective in abating serious mold
infestations. However, an individual mold spore is generally killed
and neutralized within minutes. Protein based allergens are
generally neutralized within minutes. Bacteria are generally killed
after an exposure time of minutes or less. Viruses are generally
killed after an exposure of less than a minute, typically after
exposure times as short as several seconds. Certain molds,
bacteria, allergens, and viruses can be more resistant to ozone
treatments than others. For example, anthrax spores have a hard
coating that is preferably "softened up" by exposure to humidity
prior to ozone treatment to ensure that all spores are destroyed by
a subsequent ozone treatment. See, e.g., R. G. Rice, Ozone Science
and Engineering, Vol. 24, pp. 151-158 (2002). In methods of
preferred embodiments, it is generally preferred to employ
treatment times of 2 to 3 hours, since such times are generally
satisfactory for abating a mold infestation, and well exceed the
lower limit of treatment time for substances such as protein-based
allergens, bacteria, and viruses. However, when it is desired to
abate a particularly virulent pathogen, such as anthrax, it can be
desired to employ a treatment time of over 3 hours, for example, a
treatment having a duration of 5, 6, 7, 8, 9, 10, 11, 12, 16, 20,
24, 28, 32, 36, 40, 44, 48 hours or more. It is also desirable,
when abating a particularly virulent pathogen, to also increase the
level of ozone and/or hydrogen peroxide. Ozone levels of 20, 30,
40, 50, 100, 200, 300, or 400 ppm or more can be desirable and the
concentration by weight of hydrogen peroxide can be increased to
more than 100%, preferably more than 125%, and most preferably more
than 150% of the concentration by weight of ozone introduced in the
area to be treated. Any suitable combination of increased time,
increased relative concentration of hydrogen peroxide, and/or
increased ozone concentration can be employed.
[0085] The methods of preferred embodiments are generally
successful in abating substances that are sourced indoors, for
example, a mold infestation, dander from a companion animal living
in a house, mite feces, tobacco smoke, volatile organic compounds
from newly installed carpeting or freshly painted walls, and the
like. Substances from outside sources, such as pollen, automobile
or diesel exhaust, and the like, can also be treated using methods
of preferred embodiments, but recurring treatments can be necessary
as such substances reenter the interior space from outside.
Areas and Materials that can be Treated
[0086] Any interior or contained space is amenable to treatment by
methods of the preferred embodiments. For example, single family
homes, apartment buildings, office buildings, schools, hospitals,
post offices, locker rooms, restaurants, ships, trains, buses,
airplanes, trucks, recreational vehicles, mobile homes,
manufactured houses, cargo containers, and the like are
particularly well-suited to treatment. The methods are particularly
well suited for use in newly constructed homes, buildings,
vehicles, and the like, which generally contain substantial
quantities of VOC sources, such as newly-installed carpeting and
flooring, fresh paint, adhesives, and the like. Larger enclosed
spaces, such as warehouses, barns, chicken houses, and other
buildings housing farm animals, grain elevators, factories,
hangars, subway systems, air terminals, and the like, can also be
treated provided that the preferred levels of ozone, hydrogen
peroxide, temperature, and humidity can be attained. In certain
embodiments, rather than seal and treat the entire volume of
enclosed space, the space can be partitioned so as to maintain the
preferred levels of ozone, hydrogen peroxide, temperature, and
humidity in areas adjacent to those to be treated. For example,
plastic sheeting can be draped over a floor or wall to be treated
so as to contain the ozone/hydrogen peroxide and humidity and
maintain the temperature adjacent to the treated area.
[0087] The methods of preferred embodiments can also be employed to
treat materials. Materials that can be treated include any
materials that can tolerate exposure to the ozone, hydrogen
peroxide, humidity, and temperature conditions of preferred
embodiments without suffering damage. For example, clothing,
bedding and linens, rugs, mail, packages, documents, furniture,
food items, agricultural products such as seeds, grains, cut
flowers, produce, fruits vegetables, and live plants, containers
and packaging materials, and the like. A suitable chamber can be
constructed that can be sealed to maintain conditions of ozone and
hydrogen peroxide concentration, humidity and temperature at
preferred levels, and the material placed inside that chamber and
subjected to treatment. In an automated process, materials can be
moved through an airlock and into the chamber for treatment for a
suitable time period, and then moved out of the chamber through
another airlock. Such automated processes can be particularly well
suited for the decontamination of large volumes of mail for
pathogens such as anthrax, or the decontamination of animal
carcasses or meat products (beef, pork, poultry, seafood, and the
like) for pathogens such as salmonella or e. coli. If the treatment
chamber is of sufficient size, vehicles such as passenger cars or
trucks hauling various cargo, rail cars, and the like can be
treated therein.
[0088] In another embodiment, it can be preferred to subject a room
or space to periodic decontamination, such as a surgical suite in a
hospital, a treatment or waiting room in a clinic, a kitchen or a
restaurant, a bar or nightclub, a theater, a bingo hall, a meat
processing area of a grocery store, or the like. In such
embodiments, it is generally preferred to permanently install
equipment in a location adjacent to the space to be treated. Such
equipment can include a control unit, security devices, an oxygen
concentrator, an ozone generator, an ultrasonic humidifier, a
hydrogen peroxide source, a heater and/or air conditioner, and a
ventilation unit. Prior to treatment at a convenient time (for
example, after work hours), the space is scanned to ensure that no
personnel are present in the room. Motion detectors, heat
detectors, video cameras and the like can be suitable for such
purposes. Once the space has been confirmed to contain no
personnel, a lock down procedure is instituted to prevent anyone
from entering the space during the treatment and to maintain
conditions within the space. Treatment is then conducted according
to preferred embodiments. After ozone levels have been reduced to
acceptable levels, the space is then unlocked. If it is necessary
to reduce ozone levels to acceptable levels in rapid fashion, ozone
destruct units can be employed. A computer can be employed to
control the lockdown and treatment process, as well as the
treatment schedule.
Assessment of Conditions
[0089] In preferred embodiments, the method typically involves an
assessment of conditions in the premises, e.g., pathogen, allergen,
or gas levels, followed by treatment with ozone/hydrogen peroxide.
An assessment is typically conducted to discover if a premises
(e.g., house, office building, boat, and the like) has a pathogen,
allergen, or other problem that can be eliminated by using the
abatement methods of preferred embodiments. If it is determined
that the problem can be effectively eliminated, abatement can be
conducted. It is also recommended that the underlying problem
responsible for the mold infestation be identified and eliminated,
so as to prevent future infestations. As part of the assessment,
mold tests, e.g., tests for specific types of mold can be
conducted. Other testing can include tests for VOCs, tests for
allergens, tests for pathogens, and the like. Ambient conditions,
including temperature and relative humidity, the size of the area
to be treated (square footage, volume), can also be measured.
During the assessment process, it is preferred to wear appropriate
protective gear, e.g., respirators, ear plugs, gloves, foot
coverings, clothing coverings, goggles, and the like. For example,
when dealing with an extensive infestation of particularly toxic
mold, it is generally preferred to wear full hazardous material
protective gear. In situations wherein the premises are subject to
odors that are unpleasant but not otherwise harmful, a respirator,
or no protection at all can be sufficient.
[0090] While assessments are typically conducted, in certain
embodiments an assessment may not be necessary. For example, when
an obvious mold infestation is present, when elimination of odors
or allergens is the major impetus behind the treatment, or when the
premises are treated on a periodic basis for chronic conditions
such as asthma triggered by dust mites, the treatment can be
initiated without performing any prior assessment.
Preparations Before Treatment
[0091] Before commencing an abatement process or other process
according to preferred embodiments, it is preferred to determine
the area or volume of the premises to be treated such that the
target dosage, the quantity, and type of treatment materials and
equipment that is sufficient to complete the abatement process can
be determined.
[0092] It is preferred to meet with the owner (or occupier) of the
building before commencing the abatement process. During the
meeting, the process can be explained and the owner can assist in
preparations for the abatement process. For example, all
individuals, unless provided with appropriate protective gear, are
instructed to leave the premises for the duration of the abatement
process. Any animals, such as pets, are removed from the premises,
and it is preferred to remove plants. It is not necessary to remove
fish. Problem areas can be identified for treatment, along with
areas that may not be amenable to treatment by the methods of
preferred embodiments, or areas wherein a contamination can reoccur
if the source of the contamination is not eliminated. Areas not
amenable to the preferred methods, due to either the location
and/or extent of the infestation, can necessitate more extensive
treatment or remediation steps, such as those employed to remove
and/or dispose of toxic waste, e.g., procedures similar to those
used in asbestos abatement.
Internet Enabled Decontamination System
[0093] After any assessment, including identification of areas for
abatement, and/or preparation, such as removing occupants, animals,
and plants from the premises, has been completed, the equipment
utilized in the mold abatement or other treatment process can be
put in place. Such equipment can include, but is not limited to,
oxygen concentrators, ozonators, ultrasonic humidifiers, ionizers,
dehumidifiers, portable power generators, air conditioners, air
compressors, vacuum systems, fans, sensors, recorders, computers,
communication devices, and the like.
[0094] Any suitable method or apparatus can be used to generate or
provide ozone. Commercially available ozone generators with
relatively low output and based on either ultraviolet or corona
discharge technology are suitable for use in preferred embodiments.
One drawback associated with commercially available generators can
include the formation of harmful nitrogen oxides along with the
ozone. Particularly preferred, however, is ozone generating
equipment that delivers substantially pure (i.e., minimal amounts
of nitrogen oxides produced) or pure ozone.
[0095] In a preferred embodiment, light weight, high output ozone
generators employing UV light are moved into the space to be
decontaminated. These generators are preferably under 15 lbs so as
to minimize the potential for worker injury. They employ sensors
which detect their current state of operation and this on-off state
is relayed to the accompanying computer control center via a
localized wireless system. Along with the generators, an ultrasonic
humidifier or humidifiers and computer control center are also
carried into the space to be treated.
[0096] In decontaminating very large spaces such as commercial or
industrial buildings, corona discharge ozone generators employing
oxygen concentrators may be used to deliver highly concentrated
quantities of ozone to the space. Oxygen concentrators are
typically heavy, requiring them to be moved about on a cart to
prevent worker injury. Therefore, the oxygen concentrator can be
maintained in a convenient location, such as in a van or on a truck
used to transport equipment utilized in the treatment process, and
the pure oxygen is then delivered from a location to any number of
ozone generators in remote locations via piping. In other
embodiments it can be desirable to have all equipment, including
the oxygen concentrator, placed within the dwelling during the
treatment process. In an industrial setting or hospital setting
wherein treatments are administered on a regular basis, it can be
preferable to permanently install the oxygen concentrator.
[0097] The computer control center is typically enclosed within an
environmentally sealed case. The computer control system can
perform any number of functions. It can communicate via radio or
other signals (wireless) or via a communication line (wire or fiber
optic) with remotely located equipment including ozone generators
as well as sensors monitoring ozone concentrations, humidity and
temperature. With this information, the computer can control dosage
to that indicated by research data covering target dosages for any
given situation. The target dosage is typically selected via a
look-up table stored in the computer's memory or storage unit that
provides optimal ozone dosages for a particular combination of
humidity, temperature, and condition being treated. As a further
adjunct, ultrasonic humidifiers or dehumidifiers can preferably be
connected to the system, permitting the control of ambient humidity
levels while at the same time introducing hydrogen peroxide into
the area being treated.
[0098] An additional function of the computer control center can
include communicating with the technician performing the treatment
and a remote office location via a combination of cell phone and
Internet technology. Each treatment system can have its own
Internet address and communication can be established with the
system from anywhere in the world as long as the system is in range
of a cell phone tower. Alternatively, the system can be connected
to an existing phone line or internet connection in the premises to
be treated, permitting access to the internet, or dial-up access to
a secure computer system in the remote office location.
[0099] An additional function of the computer control center can
include a Global Positioning System (GPS) transmitter which will be
used to communicate the position of the computer thereby allowing
the technician and the company employing the technician to track
the computer control system at all times.
[0100] Power to the system can be provided from a dedicated
generator or battery, or the system can utilize existing utility
outlets in the premises to be treated.
[0101] In a preferred embodiment suitable for use in typical
residential settings, the system features include a number of light
weight, high output, hand carried UV based ozone generators (number
dependent on volume and pollutant to be treated), one or more
ultrasonic humidifiers with built in humidity control devices and
reservoirs capable of containing a water/hydrogen peroxide mixture,
computer control center, manual temperature and humidity sensors,
distribution/evacuation fans, power generator (as necessary) and
ozone destruct unit (as necessary)
[0102] In another embodiment suitable for use in typical
residential settings, the dosage is calculated manually and the
equipment consisting of ozone generators, one or more ultrasonic
humidifiers with built in humidity control devices and reservoirs
capable of containing a water/hydrogen peroxide mixture, manual
temperature and humidity sensors, distribution/evacuation fans, is
placed in the residence and the decontamination period is
controlled by the technician according to the manually calculated
dosage.
[0103] In a preferred embodiment suitable for use in typical larger
commercial or industrial settings the system features include the
following: cart mounted oxygen concentrator, computer control
center, ozone destruct unit, heat exchanger, air compressor and
cell phone communication unit; up to 5 hose reels and holders for
oxygen distribution hoses; up to 5 ozone generation units with
ozone sensors; up to 5 ultrasonic humidifiers with water reservoirs
capable of containing aqueous hydrogen peroxide, up to 5 humidity
sensors; up to 5 radio wave send/receive units.
[0104] The oxygen concentrator carried on the cart case generates
and supplies highly concentrated oxygen to the remotely located
ozone generators. The cart mounted reels preferably hold up to 100
feet of 1/4 inch vinyl tubing which carries the concentrated oxygen
to the ozone generators strategically located throughout the
premises being decontaminated. Any suitable tubing can be used,
provided it is substantially inert to ozone or oxidation, such as
stainless steel tubing, inert plastic tubing, or the like. To
prevent premature failure due to the corrosive properties of ozone,
only non-ozonated air can be used to supply the oxygen
concentrator. An ozone destruct unit is preferably mounted in the
concentrator's inlet air supply. This unit eliminates the ozone in
the concentrator's air supply and greatly prolongs the life of the
unit. As further protection, the cart case can house a heat
exchanger to ensure that temperatures within the unit remain below
the temperature specification limits set by the concentrator's
manufacturer.
[0105] As previously mentioned, sensors mounted on the ozone
generators will detect ozone, humidity and temperature levels.
Ozone generation will be regulated according to the required target
dosages for the particular problem being treated. Dosage tables
generated by laboratory experimentation and further adapted through
field-testing are used to determine optimal dosage levels. These
dosage tables are stored in the computer and used to calculate the
ozone/hydroxyl levels, humidity, and time required to complete
specific decontamination tasks. While it is generally preferred to
employ a computer to determine the proper ozone, humidity, and
temperature levels, any suitable method can be employed. For
example, manual calculations can be performed, or a printed look-up
table can be employed. An advantage to using a computer is that
levels can be rapidly determined and adjusted as needed if ambient
conditions change over the course of treatment. Changes in dosages
over time can also be conveniently tracked. FIG. 1 provides a
schematic of a preferred ozone generator and ultrasonic humidifier
system capable of delivering ozone at a rate of 60 g/hour along
with hydrogen peroxide at a concentration by weight that is about
75% to about 150% of the ozone concentration to be delivered.
[0106] In preferred embodiments, operation support is provided via
several systems, including technician training, providing
equipment, delivering treatment, providing technical data, and
maintaining customer and technical databases. Technician training
typically includes detail on how the service is performed, gives
some detail on ozone, hydrogen peroxide, ozone generators,
ultrasonic humidifiers, sensors etc., with a strong emphasis on
safety; training in all aspects of sales and customer relations;
specific details on equipment operation, sensors, safe operation
and maintenance of vehicles, and the like, as well as more detail
on the chemistry behind the process; legal, moral and ethical
aspects of dealing with customers and representing the company;
detailed explanation of existing sales and marketing programs and
how the technicians are involved in these programs; functional
aspects of the sales and operations databases as well as efficient
scheduling; business training for those who may, in the future, be
operating a central office location; and details on accounting,
legal, personnel management, and other responsibilities.
[0107] Equipment for residential and small commercial treatment
typically includes fully equipped trucks or vans. Each truck or van
is preferably equipped with sufficient ozone generating equipment
to service 2 to 4 jobs per day, depending upon the size of the
premises and the contaminant involved. The trucks and vans are
equipped with all necessary safety gear to ensure that neither the
technicians nor the customers are endangered in any way. The trucks
and vans also have small coolers in which to transport samples
(e.g., mold spores) and a laptop computer equipped with the
appropriate software and which is updated daily with the
appropriate work orders and customer information. Once at the job
site, the technicians use the laptop computers to collect any
job-related information desired, including, but not limited to,
volume and/or area treated, ozone concentration levels,
temperature, humidity, customer comments, technician comments, and
the like. The laptops can be directly connected to a main computer
system through the Internet or through landlines. This allows
automatic updates of databases, immediate notification of
scheduling changes, and updated customer information as well as
identification of the current location of the service truck.
[0108] Incoming calls from prospective customers are preferably
managed in a highly professional manner through a centralized call
center. Standardized phone protocol is utilized, emphasizing
courtesy while obtaining all pertinent information as quickly as
possible. When necessary, the call center can provide a description
of the service as well as respond to a host of frequently asked
questions (FAQ's). The first image of the company is the courtesy
and professionalism of the voice on the line. Telephone closing
techniques as known in the art can be used when appropriate by
company representatives.
[0109] In certain preferred embodiments, lead development
information is collected and loaded into the company's sales and
marketing database. Any suitable database software can be used,
however, it is preferred that the software be Internet compatible,
i.e., the database can be updated and/or modified via the Internet.
The program accumulates contact information, for the purposes of
tracking contacts, their histories, and pending actions. It is
accessible on-site or from remote locations. The system is also
used to produce automated direct marketing campaigns. The system is
fully capable of expanding to accommodate business growth and is
integrated with the technical database software that has been
installed. The database is preferably customized to better function
as a technical database for use in the preferred embodiments. It
can be customized to produce work orders, invoices and to
accumulate each job's technical data including tests results,
treatment data, and customer reactions. This software allows a
database to be built on efficacy of the process in different
conditions and with different types of contaminants.
[0110] Any suitable computer network can be employed in those
embodiments wherein a computer is desirable for some aspect of the
treatment or subsequent data storage or analysis. A computer
network based on a T1 backbone and server running MS 2000 Server
software available from Microsoft Corporation is utilized in a
preferred embodiment. The system has full security and is set up as
a Virtual Private Network (VPN) allowing authorized users access
from any Internet connection. This also allows the technicians the
capability of accessing the network from home or any other location
with Internet access.
Pretreatment
[0111] In certain embodiments, it can be desirable to pre-treat the
area prior to subjecting the area to ozone treatment. A preferred
pretreatment involves subjecting the area to be treated with
humidity. Certain pathogens, such as mold spores and anthrax, are
resistant to conventional ozone treatment. The anthrax bacterium,
for example, possesses a hard shell that resists penetration by
ozone. By subjecting anthrax to humidity prior to ozone treatment,
the ozone, and/or hydroxyl is better able to penetrate the
microorganism and destroy it. Likewise, mold spores are resistant
to penetration by ozone, but can be made more amenable to treatment
by first subjecting them to humidity. Treatment of VOCs is also
facilitated by humidity. Ozone reacts with the atmospheric water
and hydrogen peroxide to produce reactive hydroxyl groups, which
then react with certain VOCs to yield less harmful or harmless
substances.
[0112] When the material to be treated includes molds, a
pretreatment consisting of exposure to a relative humidity of 70%
to 95% is typically employed. Typical pretreatment exposure times
of 10 minutes, 15 minutes, 30 minutes 45 minutes, 1 hour, 1.5
hours, 2 hours, 2.5 hours, 3 hours, 4 hours, or more can be
employed, depending upon the substances to be abated and the nature
of the space or material to be abated. In residential mold
remediation, pretreatment times of from 30 minutes to 2 hours are
generally preferred. In decontaminating a material infested with
anthrax, pretreatment times of from 12 hours to 24 hours are
generally preferred.
Abatement of Living and Working Spaces
[0113] If the area to be treated has an air duct system (e.g.,
heating or heating/air conditioning system), it is preferred to
position one or more ozonators and humidifiers adjacent to the
return air inlet. Typically, for treating volumes of 25,000 cu. ft.
or less, it is preferred that at least 10 g/hr of ozone is drawn
into each air inlet. However, in certain embodiments satisfactory
results can be obtained at a lower level of ozone generation, for
example, at about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, or 9 or more
g/hr. Likewise, in certain embodiments a higher level of ozone
generation can be preferred, for example, about 10, 11, 12, 13, 14,
15, 20, 25, 30, 40, 50, 60, 70, 80, 90, or 100 or more g/hr. Along
with the higher level of ozone generation is a proportionately
higher level of hydrogen peroxide introduction, generally at a
concentration by weight that is 75% to 150% of concentration by
weight of ozone provided. Commercially available ozonators are
available in a variety of sizes. Size is generally reported in
terms of ozone output in grams/hour. It is generally preferred to
locate mid-sized (e.g., 6. 10 or 15 gm/hr) ozonators in larger
areas, e.g., living room, kitchen/family room, open stairways, open
office spaces, and the like. Smaller ozone generators (e.g., 1-5
gm/hr) are preferably situated in small or closed-in areas, or
areas that are unlikely to get circulating air, for example,
basements, storage areas, and the like. Generally dosage
calculations show that ozone generators that are capable of
generating 60 g/hr of ozone are sufficient to treat a 2,000 sq. ft.
house with forced air ducting. More ozone can be preferred for a
house without forced air ducting. Typically, dosage calculations
show that one gram of ozone per hour is preferably delivered for
every 250 cu. ft. of area to be treated. More or less ozone can be
desirable, depending on humidity, temperature, and specific
condition being treated. Therefore, for each 1 gm/hr of delivered
ozone, an area of 33 sq. ft. with 8 ft ceilings can be
decontaminated. Determination of the amount of ozone required is
made according to the target dosage found in the dosage tables
relating time of treatment to the ozone concentration, delivered
hydrogen peroxide, humidity and temperature to the problem be
treated such as mold, allergens, pathogens or VOCs.
[0114] After the ozone generators are situated and turned on, the
forced air system is then turned on to circulate the air. It is
generally preferred that no heating or cooling of the air is
conducted, however, in certain embodiments it can be preferred to
heat or cool the air so as to obtain optimal abatement results.
[0115] Humidity is a significant factor in the kill rate of
allergens and pathogens. In general, the higher the humidity, the
faster the ozone kills the pathogen or destroys the allergen. While
not wishing to be bound to any particular theory or mechanism, it
is believed that the ozone reacts with the water vapor forming
hydroxyl radicals thereby increasing the effectiveness of the
process. Generally, it is preferred that the relative humidity in
the premises to be treated be at least 30% or more, preferably the
relative humidity is at least 40%, 45%, 50%, 55%, or 60% or more,
more preferably the relatively humidity is from 65% to about 70%,
75%, 80%, 85%, or 90% and most preferably the relative humidity is
from about 70% to about 90% or 95%. Relative humidities greater
than 95%, especially relative humidities of 100%, are generally not
preferred due to the risk of condensation, which can lead to
bleaching of sensitive materials. However, in certain embodiments
relative humidities greater than 95% can be acceptable if sensitive
materials are not a concern. In order to ensure that there is
adequate formation of hydroxyl radicals, specifically at low
humidity levels, hydrogen peroxide is preferably supplied to the
area being treated at a concentration by weight that is up to about
150% or more (preferably about 75% to about 150%) of the
concentration by weight of ozone being delivered. For example, if
the area is being treated with about 60 g/hr of ozone, then from
about 45 to 90 g/hr of hydrogen peroxide is also delivered. At low
humidities, and for the abatement of particularly virulent
pathogens, it is generally preferred to employ higher relative
concentrations of hydrogen peroxide, preferably greater than 100%,
125%, or 150% or higher.
[0116] In coastal areas, ambient humidity can provide optimal
results. In these situations the ultrasonic humidifiers are used
only to deliver a minimal amount of hydrogen peroxide. However, in
desert areas or under low humidity conditions (e.g., winter in
northern areas of the United States), it can be preferred to
increase the humidity via one or more ultrasonic humidifiers so as
to achieve optimal results. Once treatment is completed, it may be
desired to employ one or more dehumidifiers to rapidly restore the
ambient humidity to the treated premises, if the premises are
humidity-controlled. In certain instances, it may not be feasible
to humidify the area to be treated. For example, the area can
contain humidity-sensitive materials (e.g., antiques, rare books,
old documents, fragile textiles or wallpaper and the like). In
those instances, treatment can be conducted under ambient humidity
conditions with the addition of hydrogen peroxide, but the duration
of the ozone treatment can be extended to ensure satisfactory
results. However under these conditions it can be desirable to
increase the ratio of delivered hydrogen peroxide to ozone from
150% to 200%, 250%, 300%, 350%, 400%, or even 1000% or more of the
concentration by weight of ozone present. Any suitable schedule of
introducing ozone, moisture, and/or hydrogen peroxide can be
employed, e.g., constant introduction of one or more of ozone,
moisture, and hydrogen peroxide, intermittent introduction of one
or more of ozone, hydrogen peroxide, and humidity, varying
concentrations, varying temperatures, and the like.
[0117] Temperature levels also correlate with the effectiveness of
the treatment method in killing mold. Generally, as temperature
increases, the effectiveness of the treatment increases. However
the amount of ozone required to achieve and maintain the target
dosage also increases as the ozone more readily reverts back to
oxygen at higher temperatures (i.e., ozone exhibits a shorter half
life at higher temperatures). Generally, it is preferred to conduct
the treatment at a temperature typically considered a "room
temperature," namely about 17.7.degree. C. (64.degree. F.),
18.3.degree. C. (65.degree. F.), 18.8.degree. C. (66.degree. F.),
19.4.degree. C. (67.degree. F.), 20.degree. C. (68.degree. F.),
20.5.degree. C. (69.degree. F.), or 21.1.degree. C. (70.degree. F.)
up to about 21.6.degree. C. (71.degree. F.), 22.2.degree. C.
(72.degree. F.), 22.7.degree. C. (73.degree. F.), 23.3.degree. C.
(74.degree. F.), 23.8.degree. C. (75.degree. F.), 24.4.degree. C.
(76.degree. F.), 25.degree. C. (77.degree. F.), 25.5.degree. C.
(78.degree. F.), 26.1.degree. C. (79.degree. F.), 26.6.degree. C.
(80.degree. F.), 27.2.degree. C. (81.degree. F.), 27.7.degree. C.
(82.degree. F.), 28.3.degree. C. (83.degree. F.), 28.8.degree. C.
(84.degree. F.), or 29.4.degree. C. (85.degree. F.). In most
residential and commercial settings, the ambient temperature falls
within this range. However, if the premises to be treated is not
equipped with heating or air conditioning, it can be preferred to
adjust the interior temperature prior to initiating treatment, or
to control the temperature at a pre-selected level during
treatment. When the ambient temperature is high and the structure
to be treated is not equipped with air conditioning, an air
conditioning unit can be provided as part of the equipment system
and used to cool the temperature, e.g., down to below 29.4.degree.
C. (85.degree. F.). Cooling the interior to below 17.7.degree. C.
(64.degree. F.) generally results in only an incremental reduction
in the rate of ozone decomposition. Thus, it is generally not
preferred to cool the interior below this temperature. If the
ambient temperature is substantially below 17.7.degree. C.
(64.degree. F.), it is generally preferred to heat the interior. In
certain conditions, the temperature in the structure to be treated
can be controlled to a pre-selected temperature, for example, a
cold storage locker or a room containing equipment or machinery
that must be operated at an elevated or reduced temperature. Under
such conditions, the treatment is preferably conducted at ambient
temperature and the ozone level and/or humidity is adjusted to
achieve optimum results. In certain embodiments, however, it can be
desirable to treat an area at temperatures outside of those
typically considered ambient temperatures. For example, a
refrigerated unit maintained at a temperature above 0.degree. C.
(32.degree. F.) can be satisfactorily treated by adjusting the
humidity, hydrogen peroxide, and ozone levels. Generally, ozone
levels are increased at low temperatures. However, lower ozone
levels of 2 to 10 ppm can be employed in conjunction with a longer
treatment time.
[0118] Ozone levels of 2 to 10 ppm are generally preferred for
treating mold and other contaminants. However, in certain
embodiments it can be preferred to employ ozone levels of 1.9, 1.8,
1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5,
0.4, 0.3, 0.2 ppm or less. In other embodiments, ozone levels of
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50 ppm
or more can be preferred. At optimal hydrogen peroxide, humidity,
and temperature levels, a longer treatment time is preferably
employed at reduced ozone levels and a shorter treatment time is
preferably employed at higher levels so as to ensure a satisfactory
kill and/or neutralization level.
[0119] In terms of the optimal combination of ozone level, hydrogen
peroxide, temperature, and humidity, it is generally preferred to
conduct a treatment at a temperature of about 21.1.degree. C.
(70.degree. F.), a relative humidity of about 85%, a hydrogen
peroxide addition of 107% by weight of ozone, and an ozone level of
about 10 ppm. Under these conditions, the length of time required
to achieve a 100% kill for mold spores is minimized. For in a
typical residential setting, a 100% kill can be achieved in about 3
hours or less. When the temperature ranges from about 15.5.degree.
C. (60.degree. F.) to about 26.6.degree. C. (80.degree. F.), i.e.,
interior temperatures typically observed for residential and
commercial buildings, it is preferred that the relative humidity be
in the range of about 70% to about 85%, and the ozone levels be in
the range of about 2 ppm to about 10 ppm (with a corresponding
hydrogen peroxide concentration by weight of 75% to 150% of that of
the ozone concentration by weight). Under these conditions, the
optimal time to achieve a 100% kill is typically about 1 to about 3
hours.
[0120] For structures situated in high humidity environments, e.g.,
the coastline, the Midwest during summer, and the like, wherein the
relative humidity ranges from about 85% to about 95% and ambient
temperatures range from about 21.1.degree. C. (70.degree. F.) to
about 32.2.degree. C. (90.degree. F.), lower ozone levels can be
employed. Under these conditions, the optimal time to achieve a
100% kill is typically about 1 to about 3 hours.
[0121] For structures situated in low humidity environments, e.g.,
desert communities, and the like, wherein the relative humidity
ranges from about 5% to about 20% and ambient temperatures range
from about 23.8.degree. C. (75.degree. F.) to about 37.7.degree. C.
(100.degree. F.), it is preferred that the relative humidity is
raised via the use of an ultrasonic humidifier or other suitable
method to from about 70% to about 85% before beginning treatment
and that the ozone levels are in the range of about 2 ppm to about
10 ppm. Under these conditions, the optimal time to achieve a 100%
kill and/or neutralization is typically about 1 to about 3 hours.
If it is not feasible to raise the humidity levels to the 70% to
85% range, then a higher level of hydrogen peroxide can be
introduced to ensure the production of sufficient hydroxyl radicals
to complete the decontamination process. Hydrogen peroxide levels
of 125% to 150% of the weight of introduced ozone can generally be
used to ensure decontamination. However under the most extreme
conditions it may be desirable to increase the ratio of delivered
hydrogen peroxide to ozone from 150% to 200%, 250%, 300%, 350%,
400%, or even 1000% or more.
[0122] In commercial and residential settings, and the like it is
preferred to open all closet and cupboard doors, and to move items
stored in cupboards and closets to facilitate air circulation.
Doors, windows, fireplace dampers, and other air egresses are
preferably closed.
[0123] In residential settings, if dust mites are problematic, it
is preferred that all linens be taken off beds and washed in
60.degree. C. (140.degree. F.) water. Mattresses are typically
removed from the box spring and leaned up against the box spring so
as to facilitate air circulation around the mattress. If feasible,
blankets, pillows, and bed spreads are preferably placed in a
manner that allows satisfactory air circulation. Exhaust fans,
e.g., in the kitchen, bathroom, and the like, are turned on, which
helps ensure that ozonated air reaches the outlet ducting of these
areas. If such fans have a variable speed, they are preferably
operated at their lowest possible level to reduce the amount of
ozone that will evacuated while at the same time ensuring that the
vent system is decontaminated.
[0124] Before the ozonators are activated, ultrasonic humidifiers
may be employed to achieve required relative humidity levels and to
deliver the hydrogen peroxide in prescribed amounts according to
the target dosage. Once target humidity levels are achieved, the
area can be evacuated of any nonessential personnel. For those
individuals remaining in the premises, a respirator (and goggles if
the respirator is not a full-face respirator) is preferably in
place before turning on the ozonators. The ozonators and
humidifiers supplying hydrogen peroxide are typically turned on
starting with the most remote areas of the premises and finishing
with the heating and air conditioning inlet or inlets last. After
the ozonators have operated for a short time period, typically
about ten minutes, it is preferred to test and record ozone,
temperature, and humidity levels. For non-automated ozonators this
will require reentering the premises and taking the necessary
readings. Once the ozone and humidity levels have reached target
dosage levels, typically at least about 2 to 10 ppm ozone and
50-90% RH, effective treatment has begun, and the premises can be
left closed for the duration of the treatment. Although 2 to 10 ppm
ozone is generally preferred, in other embodiments a higher or
lower ozone level can be desirable, e.g., less than 0.1, 0.5, 1, 2
ppm ozone up to about 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 500,
1000, 2000, 3000, 4000, 5000 ppm ozone or more. For these higher
levels of ozone, proportionately higher levels of hydrogen peroxide
are also generally preferred, again based on the 75% to 150%
hydrogen peroxide to ozone by weight. If the contamination is
particularly extensive or the mold to be abated particularly toxic,
higher ozone levels can be preferred. To prevent injury, all doors
and other possible entrances to the building are preferably locked
and caution signs placed the entrances.
[0125] Humidity, temperature, and ozone concentration readings are
typically recorded in each room during the course of the treatment
procedure. These recordings can be obtained automatically, e.g., by
stand-alone recorders in the rooms or by the ozone generator
equipped with measuring devices. Alternatively, the recordings can
be obtained manually at pre-selected intervals.
[0126] Treatment is typically continued for up to 48 hours
depending on the target dosage which relates temperature, humidity,
ozone concentration, and condition being treated to treatment time.
After treatment is completed, the ozonators and humidifiers are
turned off and ozonated air can be evacuated from the premises if
immediate occupancy is desired. Alternatively the ozone can be left
to degrade back to oxygen if immediate occupancy is not required.
If immediate occupancy is desired fans are typically placed in one
or more doorways and/or windows to blow ozonated air out of the
premises. High volume fans (9400 c.f.m.) are generally preferred
for residential applications; however fans capable of moving more
air or less air than 9400 c.f.m. can also be suitable for use. The
evacuation fans are typically operated for 30 minutes, and then
ozone levels are tested, especially in areas where circulation from
the fans is lowest, such as bedrooms, basement, and the like.
Depending upon the circulation efficiency, longer or shorter
operation times can be preferred.
[0127] As an alternative to the use of evacuation fans, the
premises can remain closed and the ozone can dissipate and/or
decompose to safe levels without taking active steps to remove
ozonated air from the premises. In an enclosed space with poor air
circulation, ozone levels will typically return to ambient levels
after about 6 hours. However, it is generally preferred to take
active measures to evacuate ozonated air such that the delay in
reoccupying the premises is minimized.
[0128] Ozone levels are periodically tested until a pre-selected
ozone level at which it is safe to reoccupy the building is
achieved. A self contained breathing apparatus or respirator is
preferably employed for testing until a level of 0.1 ppm ozone,
0.05 ppm ozone, or less is recorded, or until levels of ozone
similar to outside ambient levels are achieved, if ambient levels
are higher than 0.1 or 0.5 ppm. An ozone level of 0.05 ppm has been
determined by the FDA to be a safe level for continuous exposure.
An ozone level of 0.1 has been determined by OSHA to be safe for
exposure times of up to 8 hours. Once the level drops below 0.05
ppm or outside ambient levels, the treated area is typically safe
for reoccupation by people, animals, and plants and treatment is
complete. If level is not below 0.05 ppm in all areas, circulation
by fans is continued until this level is reached. While 0.05 ppm is
the preferred level deemed safe for reoccupation, in certain
embodiments it can be preferred that a lower level be attained,
e.g., a level characteristic of ambient ozone levels prior to
treatment. Alternatively, a higher level of ozone can be acceptable
in certain embodiments.
[0129] Ozone levels can be tested using commercially available
instrumentation, such as that manufactured by Eco Sensors of Santa
Fe, N. Mex. When testing for current ozone levels, the instrument
is used in accordance with the manufacturer's instructions. These
typically include allowing adequate warm up time (generally at
least 5 minutes), not blocking the air flow into the instrument
while testing, making all measurements in still air as moving air
can affect the readings, keeping the instrument away from the body
as body odors can bias the reading, not using the instrument to
take measurements directly from the outlet of the ozonators which
can result in incorrect readings and/or damage to the
instrument.
[0130] After the premises has been deemed safe for reoccupation,
doors and windows can be unlocked, caution signs can be removed,
and all equipment, including fans, ozonators, and humidifiers can
be removed from the premises.
[0131] It is noted that in the case of allergens and pathogens,
treatment does not remove the allergen or pathogen from the treated
area. In the case of a pathogen, such as mold spores, the organism
is killed. If the pathogen has an ability to produce an allergic
reaction, this ability is also neutralized. In the case of an
allergen such as animal dander or dust mite feces, the protein
causing the allergic reaction is neutralized by the ozone treatment
such that it is unable to cause an allergic reaction. A subsequent
cleaning step to remove the dead organism or deactivated allergen
can be desirable in certain embodiments, but is not necessary.
Pretreatment and Post-Treatment for Ozone Control
[0132] After an ozone treatment is administered and ozone returns
to ambient levels, a strong ozone odor can still be noticeable. If
there is such an odor, it is generally associated with closets and
bedrooms. While not wishing to be bound to any particular theory,
it is believed that fabrics or other materials containing natural
or synthetic fibers having an electrostatic charge can attract and
hold ozone, slowly releasing it back into the surrounding air at
safe but noticeable levels. While a large portion of the population
considers ozone to have a pleasant odor, some individuals consider
the odor unpleasant. Other individuals, typically those suffering
from asthma, can find ozone to be an irritant. Accordingly, a
method for reducing or eliminating lingering ozone or the odor
associated with ozone is desirable.
[0133] Any suitable method can be employed for destroying or
removing lingering ozone. For example, ultraviolet (UV) light is
preferably employed. A UV light source can be brought into the
space treated, and the light therefrom can be passed over the
materials that are holding the ozone, such as bedding, clothes,
drapes, and the like. The UV treatment is preferably conducted
after completion of the ozone treatment, most preferably as soon as
detected ozone levels reach ambient levels.
[0134] Removal of ozone can also be accelerated by subjecting the
interior spaces to elevated temperatures, for example, by a radiant
heater or hot air blower.
[0135] In other embodiments, it can be preferred to employ ions.
Depending upon the nature of the materials in the treated space, it
can be desirable to employ only positive or negative ions, or to
employ positive ions for a time followed by negative ions, or vice
versa. Any suitable equipment for generating ions can be employed.
It is generally preferred to employ an ion generator capable of
producing 1.times.10.sup.12 ions per second (negative or positive).
Such an ion generator is generally suitable for use in rooms or
spaces having an area of approximately 500 sq. ft. Alternatively,
bipolar ionization can be employed. Bipolar ionization uses an
alternating current to produce both positive and negative ions.
Bipolar ionization utilizes a process involving association and
disassociation to generate a highly reactive mixture of ionized gas
consisting of atoms, molecules, and free radicals capable of
creating chemical changes. There are several types of devices that
can be used for this process. For HVAC applications, a non-thermal
type of surface discharge reactor is preferably used. Bipolar
ionization was first used commercially in 1972 in the food and meat
industry in Western Europe to improve shelf life of perishable
foods with limited or no mechanical refrigeration.
[0136] When the bipolar ion generator is connected to an
oscilloscope, a sinusoidal waveform is observed. On one side of the
waveform, the bipolar generator produces positively charged ionized
gas molecules and on the other side of the waveform, the bipolar
generator produces negatively charged ionized gas molecules. This
is a pulsed AC system, which alternately produces negative and
positively ionized gas molecules. In operation, a pulsed ion field
is created in the vicinity of the bipolar generator. As air passes
through the ion field, electrons in the valence shells of stable
molecules receive excitation energy. As the air stream moves out of
the ion field and through the air-handling unit, the electron
vibrational energy permits valence electrons to overcome nuclear
attraction and escape. Chemical bonds are broken in gas molecules,
ionic compounds disassociate to positive and negative ions, and
covalent compounds disassociate to free radicals. In the absence of
a polar field, the highly unstable ions and free radicals combine
to form more stable compounds.
[0137] To determine what type or types of ions are preferred for
treating a space, the materials contained within the space can be
classified on the basis of their place in a triboelectric series.
Below is a very short triboelectric series that provides an
indication of the ordering of some common materials. A material
that charges positive will be the one that is closer to the
positive end of the series and the material closer to the negative
end will charge negatively. Accordingly, to reduce the charge on
the material, ions of opposite polarity can be applied. It is the
work function of the material that determines its position in the
series. In general, materials with higher work function tend to
appropriate electrons from materials with lower work functions.
Triboelectric series (from positive to negative): positive
(+)>asbestos>glass>nylon>wool>lead>silk>aluminum>-
paper>cotton>steel>hard rubber>nickel &
copper>brass & silver>synthetic
rubber>Orlon>saran>polyethylene>Teflon>silicone
rubber>negative (-). While such triboelectric series can be
helpful in determining the preferred ion treatment, other factors
can affect the preferred treatment. For example, real materials are
seldom very pure and often have surface finishes and/or
contamination that strongly influence triboelectrification. The
spacing between materials on a triboseries does not allow one to
predict with any confidence the magnitude of the charge separated.
Many factors besides the difference in the electronic surface
energy, including surface finish, electrical conductivity, and
mechanical properties, can also strongly influence results.
[0138] In addition to controlling ozone odor, bipolar ionization
methods can yield additional benefits, including microbiological
control, control of other odors and gas phase chemicals, static
control, and filtration enhancement. After dissipating the
ionization energy, air with a balanced electrical charge remains.
In the absence of any electrical charge, submicroscopic
particulates are not attracted to foreign surfaces and remain
airborne and naturally buoyant. Air currents established by an
efficient air distribution system displace the particulates and
carry them back to the filters in the air-handling unit.
Particulates that pass through the filters remain buoyant on
subsequent circulation cycles and are returned to the filters for
another attempt at removal. With every pass through the filters,
the probability increases for removal.
[0139] It is generally preferred to employ an ion treatment during
the ozone treatment. However, an ion treatment can also be
conducted before or after the ozone treatment, or at any suitable
time.
Remediation of Norwalk Virus
[0140] Interior spaces, such as in cruise ships, infected with
Norwalk virus can be remediated by methods of preferred
embodiments. The procedure generally preferred is as follows: Ships
are generally constructed such that sections of the ship can be
isolated from the remainder of the ship. These sections have
independent heating, ventilating, and air conditioning systems
(HVAC) as well as sealable doors providing total isolation.
Humidification and ozonation equipment can be brought aboard the
ship and placed within one or more of the isolatable sections. The
ultrasonic humidifiers and ozonators can be placed near or within
the air inlets of the HVAC system and all systems placed in
operation. This circulates the ozone, hydrogen peroxide, and
humidity throughout the isolated section of the ship at target
dosages determined to be lethal to the Norwalk and other viruses
and bacteria. Once the target dosage has been achieved then the
ozone can be left to decompose back to oxygen or it can be
evacuated by opening the outside makeup air system to allow 100%
makeup air, thereby evacuating the ozone and allowing rapid
reoccupation of the treated section.
Remediation of Anthrax
[0141] Methods of preferred embodiments are suitable for use in
decontaminating indoor areas or materials contaminated with
anthrax. The procedure generally preferred is similar to that noted
for Norwalk virus, with the exception that the area to be treated
is pre-treated with humidity for a period of 12 to 24 hours at
levels of humidity greater than 70%. Ultrasonic humidifiers are
placed within the area to be treated. They are turned on and
allowed to operate until such time as a level of at least 90%
relative humidity is achieved. Once this level has been achieved,
the pretreatment period has begun. Once the pretreatment period has
been concluded, the actual treatment can be completed based on
target dosages for anthrax. Target dosages for anthrax require that
the amount of hydrogen peroxide relative to ozone introduced via
the ultrasonic humidifiers to the treatment area is higher than in
other decontamination situations, preferably at least from about
125 to 150%, but in certain embodiments even higher. With regard to
safety issues, significantly more stringent safety procedures are
required when treating an area contaminated with anthrax or other
particularly virulent pathogens. Scientifically accepted hazardous
material safety procedures are followed strictly by all personnel
involved in the decontamination procedure.
EXAMPLE
Santa Monica House
[0142] A private residence located in Santa Monica, Calif. was
treated with ozone according to a preferred method. A full study of
the "before treatment" and "after treatment" conditions in the
house was conducted by an independent Indoor Air Quality
specialist. The testing portion of the study consisted of taking
air samples outside the house to determine background levels of
contaminants and in 3 rooms within the house. These tests were
conducted on Feb. 14, 2002 (before treatment) and then again on
Feb. 21, 2002 (after treatment). The results of the study showed
that, in the two bedrooms tested, all types of identified mold
spores were reduced below that of the outdoor air (i.e., a 100%
kill), while in the dining room the very high levels of
Penicillium/Aspergillus (12,339 spores/m.sup.3) were reduced by
more than 99% while the levels all other fungi types were equal to
or below that of the outdoor air (a 100% kill). The graphs provided
in FIGS. 2, 3, and 4 provide a visual representation of the results
obtained in the Santa Monica home's dining room, master bedroom,
and second bedroom, respectively, and are typical of the results
obtained using the method of the preferred embodiments.
[0143] Examples of mold levels before and after treatment according
to the method of the preferred embodiments are provided in Table 1.
The numbers refer to total mold count for all mold types.
TABLE-US-00001 TABLE 1 Total Mold Count (spores/m.sup.3) Treatment
Location Before After 1 master Bath Skylight 30,900 681 1 Master
Bath Above Shower 526,000 0 1 Family Room Ceiling 641,000 0 2 Above
Shower 672,000 0 2 Bedroom/Closet Wall 18 0 2 entry Closet 86,900
276 3 Master Bedroom 8,620 755 3 Shower 110 0 4 n/a 200 5 5 garage
43,200 681
[0144] All references cited herein are incorporated herein by
reference in their entirety and are hereby made a part of this
specification. To the extent publications and patents or patent
applications incorporated by reference contradict the disclosure
contained in the specification, the specification is intended to
supersede and/or take precedence over any such contradictory
material.
[0145] The term "comprising" as used herein is synonymous with
"including," "containing," or "characterized by," and is inclusive
or open-ended and does not exclude additional, unrecited elements
or method steps.
[0146] All numbers expressing quantities of ingredients, reaction
conditions, and so forth used in the specification and claims are
to be understood as being modified in all instances by the term
"about." Accordingly, unless indicated to the contrary, the
numerical parameters set forth herein are approximations that may
vary depending upon the desired properties sought to be obtained.
At the very least, and not as an attempt to limit the application
of the doctrine of equivalents to the scope of any claims in any
application claiming priority to the present application, each
numerical parameter should be construed in light of the number of
significant digits and ordinary rounding approaches.
[0147] The above description discloses several methods and
materials of the present invention. This invention is susceptible
to modifications in the methods and materials, as well as
alterations in the fabrication methods and equipment. Such
modifications will become apparent to those skilled in the art from
a consideration of this disclosure or practice of the invention
disclosed herein. Consequently, it is not intended that this
invention be limited to the specific embodiments disclosed herein,
but that it cover all modifications and alternatives coming within
the true scope and spirit of the invention.
* * * * *