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U. S. Department of Labor
Occupational Safety and Health Administration
Directorate of Science, Technology and Medicine
Office of Science and Technology Assessment |
A Brief Guide to Mold in the Workplace
Safety and Health Information Bulletin
SHIB 03-10-10
This Safety and Health Information Bulletin is not a standard or regulation, and it creates no new legal obligations. The Bulletin is advisory in nature, informational in content, and is intended to assist employers in providing a safe and healthful workplace. Pursuant to the Occupational Safety and Health Act, employers must comply with hazard-specific safety and health standards promulgated by OSHA or by a state with an OSHA-approved state plan. In addition, pursuant to Section 5(a)(1), the General Duty Clause of the Act, employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm. Employers can be cited for violating the General Duty Clause if there is a recognized hazard and they do not take
reasonable steps to prevent or abate the hazard. However, failure to implement any recommendations in this Safety and Health Information Bulletin is not, in
itself, a violation of the General Duty Clause. Citations can only be based on standards, regulations, and the General Duty Clause. |
Introduction
Concern about indoor exposure to mold has
increased along with public awareness that
exposure to mold can cause a variety of health
effects and symptoms, including allergic reactions.
This safety and health information bulletin
provides recommendations for the prevention of
mold growth and describes measures designed to
protect the health of building occupants and
workers involved in mold cleanup and prevention.
This bulletin is directed primarily at building
managers, custodians, and others responsible for
building maintenance, but may also be used as a
basic reference for those involved in mold
remediation.
By reading this safety and health
information bulletin, individuals with little or no
experience with mold remediation may be able to
reasonably judge whether mold contamination can
be managed in-house or whether outside assistance
is required. The advice of a medical professional
should always be sought if there are any emerging
health issues. This document will help those
responsible for building maintenance in the
evaluation of remediation plans. Contractors and
other professionals (e.g. industrial hygienists or
other environmental health and safety
professionals) who respond to mold and moisture
situations in buildings, as well as members of the
general public, also may find these guidelines
helpful.
The information in these guidelines is
intended only as a summary of basic procedures
and is not intended, nor should it be used, as a
detailed guide to mold remediation. These
guidelines are subject to change as more
information regarding mold contamination and
remediation becomes available.
Mold Basics
Molds are part of the natural environment.
Molds are fungi that can be found anywhere -
inside or outside - throughout the year. About
1,000 species of mold can be found in the United
States, with more than 100,000 known species
worldwide.
Outdoors, molds play an important role in
nature by breaking down organic matter such as
toppled trees, fallen leaves, and dead animals. We
would not have food and medicines, like cheese and
penicillin, without mold.
Indoors, mold growth should be avoided.
Problems may arise when mold starts eating away
at materials, affecting the look, smell, and possibly,
with the respect to wood-framed buildings,
affecting the structural integrity of the buildings.
Molds can grow on virtually any substance,
as long as moisture or water, oxygen, and an
organic source are present. Molds reproduce by
creating tiny spores (viable seeds) that usually
cannot be seen without magnification. Mold
spores continually float through the indoor and
outdoor air.
Molds are usually not a problem unless
mold spores land on a damp spot and begin
growing. They digest whatever they land on in
order to survive. There are molds that grow on
wood, paper, carpet, foods and insulation, while
other molds feast on the everyday dust and dirt that
gather in the moist regions of a building.
When excessive moisture or water
accumulates indoors, mold growth often will
occur, particularly if the moisture problem remains
uncorrected. While it is impossible to eliminate all
molds and mold spores, controlling moisture can
control indoor mold growth.
All molds share the characteristic of being
able to grow without sunlight; mold needs only a
viable seed (spore), a nutrient source, moisture,
and the right temperature to proliferate. This explains
why mold infestation is often found in damp, dark,
hidden spaces; light and air circulation dry areas out,
making them less hospitable for mold.
Molds gradually damage building materials
and furnishings. If left unchecked, mold can
eventually cause structural damage to a wood framed building, weakening floors and walls as it
feeds on moist wooden structural members. If you
suspect that mold has damaged building integrity,
consult a structural engineer or other professional
with the appropriate expertise.
Since mold requires water to grow, it is
important to prevent excessive moisture in
buildings. Some moisture problems in buildings
have been linked to changes in building
construction practices since the 1970s, which
resulted in tightly sealed buildings with diminished
ventilation, contributing to moisture vapor
buildup. Other moisture problems may result from
roof leaks, landscaping or gutters that direct water
into or under a building, or unvented combustion
appliance. Delayed or insufficient maintenance
may contribute to moisture problems in buildings.
Improper maintenance and design of building
heating/ventilating/air-conditioning (HVAC)
systems, such as insufficient cooling capacity for
an air conditioning system, can result in elevated
humidity levels in a building.
Health Effects
Currently, there are no federal
standards or recommendations, (e.g., OSHA,
NIOSH, EPA) for airborne concentrations of
mold or mold spores. Scientific research on the
relationship between mold exposures and health
effects is ongoing. This section provides a brief
overview, but does not describe all potential health
effects related to mold exposure. For more
detailed information, consult a health professional
or your state or local health department.
There are many types of mold. Most typical
indoor air exposures to mold do not present a risk of
adverse health effects. Molds can cause adverse
effects by producing allergens (substances that can
cause allergic reactions). Potential health concerns are
important reasons to prevent mold growth and to
remediate existing problem areas.
The onset of allergic reactions to mold can
be either immediate or delayed. Allergic responses
include hay fever-type symptoms such as runny
nose and red eyes.
Molds may cause localized skin or mucosal
infections but, in general, do not cause systemic
infections in humans, except for persons with
impaired immunity, AIDS, uncontrolled diabetes,
or those taking immune suppressive drugs. An
important reference with guidelines for immuno-compromised individuals can be found at
the Centers for Disease Control and Prevention (CDC) website.
Molds can also cause asthma attacks in
some individuals who are allergic to mold. In
addition, exposure to mold can irritate the eyes,
skin, nose and throat in certain individuals.
Symptoms other than allergic and irritant types are
not commonly reported as a result of inhaling mold
in the indoor environment.
Some specific species of mold produce
mycotoxins under certain environmental
conditions. Potential health effects from
mycotoxins are the subject of ongoing scientific
research and are beyond the scope of this
document.
Eating, drinking, and using tobacco
products and cosmetics where mold remediation is
taking place should be avoided. This will prevent
unnecessary contamination of food, beverage,
cosmetics, and tobacco products by mold and other
harmful substances within the work area.
Prevention
Moisture control is the key to mold control.
When water leaks or spills occur indoors - act
promptly. Any initial water infiltration should be
stopped and cleaned promptly. A prompt response
(within 24-48 hours) and thorough clean- up,
drying, and/or removal of water-damaged materials
will prevent or limit mold growth.
Mold prevention tips include:
- Repairing plumbing leaks and leaks in the
building structure as soon as possible.
- Looking for condensation and wet spots.
Fix source(s) of moisture incursion
problem(s) as soon as possible.
- Preventing moisture from condensing by
increasing surface temperature or reducing
the moisture level in the air (humidity). To
increase surface temperature, insulate or
increase air circulation. To reduce the
moisture level in the air, repair leaks,
increase ventilation (if outside air is cold
and dry), or dehumidify (if outdoor air is
warm and humid).
- Keeping HVAC drip pans clean, flowing
properly, and unobstructed.
- Performing regularly scheduled building/
HVAC inspections and maintenance,
including filter changes.
- Maintaining indoor relative humidity below
70% (25 - 60%, if possible).
- Venting moisture-generating appliances,
such as dryers, to the outside where
possible.
- Venting kitchens (cooking areas) and
bathrooms according to local code
requirements.
- Cleaning and drying wet or damp spots as
soon as possible, but no more than 48
hours after discovery.
- Providing adequate drainage around buildings
and sloping the ground away from building
foundations. Follow all local building codes.
- Pinpointing areas where leaks have
occurred, identifying the causes, and taking
preventive action to ensure that they do not
reoccur.
Questions That May Assist in Determining
Whether a Mold Problem Currently Exists
- Are building materials or furnishings
visibly moisture damaged?
- Have building materials been wet more
than 48 hours?
- Are there existing moisture problems in the
building?
- Are building occupants reporting musty or
moldy odors?
- Are building occupants reporting health
problems that they think are related to mold
in the indoor environment?
- Has the building been recently remodeled
or has the building use changed?
- Has routine maintenance been delayed or
the maintenance plan been altered?
Always consider consulting a health professional
to address any employee health concerns.
Remediation Plan
Remediation includes both the identification
and correction of the conditions that permit mold
growth, as well as the steps to safely and effectively
remove mold damaged materials.
Before planning the remediation assess the
extent of the mold or moisture problem and the
type of damaged materials. If you choose to hire
outside assistance to do the cleanup, make sure the
contractor has experience with mold remediation.
Check references and ask the contractor to follow
the recommendations in EPA's publication, "Mold
Remediation in Schools and Commercial
Buildings," or other guidelines developed by
professional or governmental organizations.
The remediation plan should include steps
to permanently correct the water or moisture
problem. The plan should cover the use of
appropriate personal protective equipment (PPE).
It also should include steps to carefully contain and
remove moldy building materials in a manner that
will prevent further contamination. Remediation
plans may vary greatly depending on the size and
complexity of the job, and may require revision if
circumstances change or new facts are discovered.
If you suspect that the HVAC system is
contaminated with mold, or if mold is present near
the intake to the system, contact the National Air
Duct Cleaners Association (NADCA), or consult
EPA's guide, "Should You Have the Air Ducts in
Your Home Cleaned?" before taking further action.
Do not run the HVAC system if you know or
suspect that it is contaminated with mold, as it
could spread contamination throughout the
building. If the water or mold damage was caused
by sewage or other contaminated water, consult a
professional who has experience cleaning and
repairing buildings damaged by contaminated
water.
The remediation manager's highest priority
must be to protect the health and safety of the building
occupants and remediators. Remediators should
avoid exposing themselves and others to mold-laden
dusts as they conduct their cleanup activities. Caution
should be used to prevent mold and mold spores from
being dispersed throughout the air where they can be
inhaled by building occupants. In some cases,
especially those involving large areas of contamination,
the remediation plan may include temporary relocation
of some or all of the building occupants.
When deciding if relocating occupants is
necessary, consideration should be given to the
size and type of mold growth, the type and extent
of health effects reported by the occupants, the
potential health risks that could be associated with
the remediation activity, and the amount of
disruption this activity is likely to cause. In
addition, before deciding to relocate occupants,
one should also evaluate the remediator's ability to
contain/minimize possible aerosolization of mold
spores given their expertise and the physical
parameters of the workspace. When possible,
remediation activities should be scheduled during
off hours when building occupants are less likely
to be affected.
Remediators, particularly those with health
related concerns, may wish to check with their
physicians or other health-care professionals
before working on mold remediation or
investigating potentially moldy areas. If any
individual has health concerns, doubts, or
questions before beginning a remediation/cleanup
project, he or she should consult a health
professional.
Mold Remediation/Cleanup Methods
The purpose of mold remediation is to
correct the moisture problem and to remove moldy
and contaminated materials to prevent human
exposure and further damage to building materials
and furnishings. Porous materials that are wet and
have mold growing on them may have to be
discarded because molds can infiltrate porous
substances and grow on or fill in empty spaces or
crevices. This mold can be difficult or impossible to
remove completely.
As a general rule, simply killing the mold,
for example, with biocide is not enough. The mold
must be removed, since the chemicals and proteins,
which can cause a reaction in humans, are present
even in dead mold.
A variety of cleanup methods are available for
remediating damage to building materials and
furnishings caused by moisture control problems
and mold growth. The specific method or group of
methods used will depend on the type of material
affected. Some methods that may be used include
the following:
Wet Vacuum
Wet vacuums are vacuum cleaners
designed to collect water. They can be used to
remove water from floors, carpets, and hard
surfaces where water has accumulated. They
should not be used to vacuum porous materials,
such as gypsum board. Wet vacuums should be
used only on wet materials, as spores may be
exhausted into the indoor environment if
insufficient liquid is present. The tanks, hoses, and
attachments of these vacuums should be
thoroughly cleaned and dried after use since mold
and mold spores may adhere to equipment
surfaces.
Damp Wipe
Mold can generally be removed from
nonporous surfaces by wiping or scrubbing with
water and detergent. It is important to dry these
surfaces quickly and thoroughly to discourage
further mold growth. Instructions for cleaning
surfaces, as listed on product labels, should always
be read and followed.
HEPA Vacuum
HEPA (High-Efficiency Particulate Air)
vacuums are recommended for final cleanup of
remediation areas after materials have been thoroughly
dried and contaminated materials removed. HEPA
vacuums also are recommended for cleanup of dust
that may have settled on surfaces outside the
remediation area. Care must be taken to assure that
the filter is properly seated in the vacuum so that all the
air passes through the filter. When changing the
vacuum filter, remediators should wear respirators,
appropriate personal protective clothing, gloves, and
eye protection to prevent exposure to any captured
mold and other contaminants. The filter and contents
of the HEPA vacuum must be disposed of in
impermeable bags or containers in such a way as to
prevent release of the debris.
Disposal of Damaged Materials
Building materials and furnishings
contaminated with mold growth that are not
salvageable should be placed in sealed
impermeable bags or closed containers while in the
remediation area. These materials can usually be
discarded as ordinary construction waste. It is
important to package mold-contaminated materials
in this fashion to minimize the dispersion of mold
spores. Large items with heavy mold growth
should be covered with polyethylene sheeting and
sealed with duct tape before being removed from
the remediation area. Some jobs may require the
use of dust-tight chutes to move large quantities of
debris to a dumpster strategically placed outside a
window in the remediation area.
Use of Biocides
The use of a biocide, such as chlorine
bleach, is not recommended as a routine practice
during mold remediation, although there may be
instances where professional judgment may
indicate its use (for example, when immuno-compromised individuals are present). In most
cases, it is not possible or desirable to sterilize an area,
as a background level of mold spores comparable to
the level in outside air will persist. However, the
spores in the ambient air will not cause further
problems if the moisture level in the building has been
corrected.
Biocides are toxic to animals and humans, as
well as to mold. If you choose to use disinfectants or
biocides, always ventilate the area, using outside air if
possible, and exhaust the air to the outdoors. When
using fans, take care not to extend the zone of
contamination by distributing mold spores to a
previously unaffected area. Never mix chlorine
bleach solution with other cleaning solutions or
detergents that contain ammonia because this
may produce highly toxic vapors and create a
hazard to workers.
Some biocides are considered pesticides,
and some states require that only registered
pesticide applicators apply these products in
schools, commercial buildings, and homes. Make
sure anyone applying a biocide is properly licensed
where required.
Fungicides are commonly applied to
outdoor plants, soil, and grains as a powder or
spray. Examples of fungicides include
hexachlorobenzene, organomercurials,
pentachlorophenol, phthalimides, and
dithiocarbamates.
Do not use fungicides developed for outdoor
use in any indoor application, as they can be extremely
toxic to animals and humans in an enclosed
environment.
When you use biocides as a disinfectant or
a pesticide, or as a fungicide, you should use
appropriate PPE, including respirators. Always,
read and follow product label precautions. It is a
violation of Federal (EPA) law to use a biocide in
any manner inconsistent with its label direction.
Mold Remediation Guidelines
This section presents remediation guidelines
for building materials that have or are likely to have
mold growth. The guidelines are designed to protect
the health of cleanup personnel and other workers
during remediation. These guidelines are based on the
size of the area impacted by mold contamination.
Please note that these are guidelines; some
professionals may prefer other remediation methods,
and certain circumstances may require different
approaches or variations on the approaches described
below. If possible, remediation activities should be
scheduled during off-hours when building occupants
are less likely to be affected.
Although the level of personal protection
suggested in these guidelines is based on the total
surface area contaminated and the potential for
remediator or occupant exposure, professional
judgment always should play a part in remediation
decisions. These remediation guidelines are based
on the size of the affected area to make it easier for
remediators to select appropriate techniques, not
on the basis of research showing there is a specific
method appropriate at a certain number of square
feet. The guidelines have been designed to help
construct a remediation plan. The remediation
manager should rely on professional judgment and
experience to adapt the guidelines to particular
situations. When in doubt, caution is advised.
Consult an experienced mold remediator for more
information.
Level I: Small Isolated Areas (10 sq. ft or less) -
e.g., ceiling tiles, small areas on walls.
- Remediation can be conducted by the
regular building maintenance staff as long
as they are trained on proper clean-up
methods, personal protection, and potential
health hazards. This training can be
performed as part of a program to comply
with the requirements of the OSHA Hazard
Communication Standard (29 CFR 1910.1200).
- Respiratory protection (e.g., N-95 disposable
respirator) is recommended. Respirators must
be used in accordance with the OSHA
respiratory protection standard (29 CFR
1910.134). Gloves and eye protection should
be worn.
- The work area should be unoccupied.
Removing people from spaces adjacent to
the work area is not necessary, but is
recommended for infants (less than 12 months
old), persons recovering from recent surgery,
immune-suppressed people, or people with
chronic inflammatory lung diseases (e.g.,
asthma, hypersensitivity pneumonitis, and
severe allergies).
- Containment of the work area is not
necessary. Dust suppression methods, such
as misting (not soaking) surfaces prior to
remediation, are recommended.
- Contaminated materials that cannot be
cleaned should be removed from the
building in a sealed impermeable plastic
bag. These materials may be disposed of
as ordinary waste.
- The work area and areas used by
remediation workers for egress should be
cleaned with a damp cloth or mop and a
detergent solution.
- All areas should be left dry and visibly free
from contamination and debris.
Level II: Mid-Sized Isolated Areas (10-30 sq.
ft.) – e.g., individual wallboard panels.
- Remediation can be conducted by the
regular building maintenance staff. Such
persons should receive training on proper
clean-up methods, personal protection, and
potential health hazards. This training can
be performed as part of a program to
comply with the requirements of the OSHA Hazard Communication Standard (29 CFR 1910.1200).
- Respiratory protection (e.g., N-95 disposable
respirator) is recommended. Respirators must
be used in accordance with the OSHA respiratory protection standard (29 CFR
1910.134). Gloves and eye protection should
be worn.
- The work area should be unoccupied.
Removing people from spaces adjacent to
the work area is not necessary, but is
recommended for infants (less than 12 months
old), persons recovering from recent surgery,
immune-suppressed people, or people with
chronic inflammatory lung diseases (e.g.,
asthma, hypersensitivity pneumonitis, and
severe allergies).
- Surfaces in the work area that could
become contaminated should be covered
with a secured plastic sheet(s) before
remediation to contain dust/debris and
prevent further contamination.
- Dust suppression methods, such as misting
(not soaking) surfaces prior to
remediation, are recommended.
- Contaminated materials that cannot be
cleaned should be removed from the
building in a sealed impermeable plastic
bag. These materials may be disposed of
as ordinary waste.
- The work area and areas used by
remediation workers for egress should be
HEPA vacuumed and cleaned with a damp
cloth or mop and a detergent solution.
- All areas should be left dry and visibly free
from contamination and debris.
Level III: Large Isolated Areas (30 –100 square feet) – e.g., several wallboard panels.
Industrial hygienists or other environmental health and
safety professionals with experience performing
microbial investigations and/or mold remediation
should be consulted prior to remediation activities to
provide oversight for the project.
The following procedures may be implemented
depending upon the severity of the contamination:
- It is recommended that personnel be trained in
the handling of hazardous materials and
equipped with respiratory protection (e.g.,
N-95 disposable respirator). Respirators
must be used in accordance with the OSHA respiratory protection standard (29 CFR
1910.134). Gloves and eye protection should
be worn.
- Surfaces in the work area and areas directly
adjacent that could become decontaminated
should be covered with a secured plastic
sheet(s) before remediation to contain dust/
debris and prevent further contamination.
- Seal ventilation ducts/grills in the work
area and areas directly adjacent with plastic
sheeting.
- The work area and areas directly adjacent
should be unoccupied. Removing people
from spaces near the work area is
recommended for infants, persons having
undergone recent surgery, immunesuppressed
people, or people with chronic
inflammatory lung diseases. (e.g., asthma,
hypersensitivity pneumonitis, and severe
allergies).
- Dust suppression methods, such as misting
(not soaking) surfaces prior to mediation,
are recommended.
- Contaminated materials that cannot be cleaned
should be removed from the building in sealed
impermeable plastic bags. These materials
may be disposed of as ordinary waste.
- The work area and surrounding areas should
be HEPA vacuumed and cleaned with a
damp cloth or mop and a detergent
solution.
- All areas should be left dry and visibly free
from contamination and debris.
Note: If abatement procedures are expected to
generate a lot of dust (e.g., abrasive cleaning of
contaminated surfaces, demolition of plaster walls) or
the visible concentration of the mold is heavy (blanket
coverage as opposed to patchy), it is recommended
that the remediation procedures for Level IV be
followed.
Level IV: Extensive Contamination (greater than
100 contiguous square feet in an area).
Industrial hygienists or other environmental health
and safety professionals with experience
performing microbial investigations and/or mold
remediation should be consulted prior to
remediation activities to provide oversight for the
project.
The following procedures may be implemented
depending upon the severity of the contamination:
- Personnel trained in the handling of
hazardous materials and equipped with:
- Full face piece respirators with
HEPA cartridges;
- Disposable protective clothing
covering entire body including both
head and shoes; and
- Gloves.
- Containment of the affected area:
- Complete isolation of work area
from occupied spaces using plastic
sheeting sealed with duct tape
(including ventilation ducts/grills,
fixtures, and other openings);
- The use of an exhaust fan with a
HEPA filter to generate negative
pressurization; and
- Airlocks and decontamination
room.
- If contaminant practices effectively prevent
mold from migrating from affected areas, it
may not be necessary to remove people
from surrounding work areas. However,
removal is still recommended for infants,
persons having undergone recent surgery,
immune- suppressed people, or people with
chronic inflammatory lung diseases. (e.g.,
asthma, hypersensitivity pneumonitis, and
severe allergies).
- Contaminated materials that cannot be cleaned
should be removed from the building in sealed
impermeable plastic bags. The outside of the
bags should be cleaned with a damp cloth and
a detergent solution or HEPA vacuumed in the
decontamination chamber prior to their
transport to uncontaminated areas of the
building. These materials may be disposed
of as ordinary waste.
- The contained area and decontamination
room should be HEPA vacuumed and
cleaned with a damp cloth or mopped with
a detergent solution and be visibly clean
prior to the removal of isolation barriers.
Personal Protective Equipment (PPE)
Any remediation work that disturbs mold and
causes mold spores to become airborne increases the
degree of respiratory exposure. Actions that tend to
disperse mold include: breaking apart moldy porous
materials such as wallboard; destructive invasive
procedures to examine or remediate mold growth in a
wall cavity; removal of contaminated wallpaper by
stripping or peeling; using fans to dry items or ventilate
areas.
The primary function of personal protective
equipment is to prevent the inhalation and ingestion of
mold and mold spores and to avoid mold contact with
the skin or eyes. The following sections discuss the
various types of PPE that may be used during
remediation activities.
Skin and Eye Protection
Gloves protect the skin from contact with
mold, as well as from potentially irritating cleaning
solutions. Long gloves that extend to the middle
of the forearm are recommended. The glove material
should be selected based on the type of substance/
chemical being handled. If you are using a biocide
such as chlorine bleach, or a strong cleaning solution,
you should select gloves made from natural rubber,
neoprene, nitrile, polyurethane, or PVC. If you are
using a mild detergent or plain water, ordinary
household rubber gloves may be used.
To protect your eyes, use properly fitted
goggles or a full face piece respirator. Goggles
must be designed to prevent the entry of dust and
small particles. Safety glasses or goggles with
open vent holes are not appropriate in mold
remediation.
Respiratory Protection
Respirators protect cleanup workers from
inhaling airborne mold, contaminated dust, and
other particulates that are released during the
remediation process. Either a half mask or full face piece air-purifying respirator can be used. A
full face piece respirator provides both respiratory
and eye protection. Please refer to the discussion
of the different levels of remediation to ascertain
the type of respiratory protection recommended.
Respirators used to provide protection from mold
and mold spores must be certified by the National
Institute for Occupational Safety and Health
(NIOSH). More protective respirators may have to
be selected and used if toxic contaminants such as
asbestos or lead are encountered during remediation.
As specified by OSHA in
29 CFR 1910.134
individuals who use respirators must be properly
trained, have medical clearance, and be properly fit
tested before they begin using a respirator. In
addition, use of respirators requires the employer to
develop and implement a written respiratory
protection program, with worksite-specific procedures
and elements.
Protective Clothing
While conducting building inspections and
remediation work, individuals may encounter
hazardous biological agents as well as chemical
and physical hazards. Consequently, appropriate
personal protective clothing (i.e., reusable or
disposable) is recommended to minimize cross-contamination between work areas and clean areas, to
prevent the transfer and spread of mold and other
contaminants to street clothing, and to eliminate skin
contact with mold and potential chemical exposures.
Disposable PPE should be discarded after it
is used. They should be placed into impermeable
bags, and usually can be discarded as ordinary
construction waste. Appropriate precautions and
protective equipment for biocide applicators
should be selected based on the product
manufacturer's warnings and recommendations
(e.g., goggles or face shield, aprons or other
protective clothing, gloves, and respiratory
protection).
Sampling for Mold
Is it necessary to sample for mold? In
most cases, if visible mold growth is present,
sampling is unnecessary. Air sampling for mold
may not be part of a routine assessment because
decisions about appropriate remediation strategies
often can be made on the basis of a visual inspection.
Your first step should be to inspect for any
evidence of water damage and visible mold growth.
Testing for mold is expensive, and there should be a
clear reason for doing so. In many cases, it is not
economically practical or useful to test for mold
growth on surfaces or for airborne spores in the
building. In addition, there are no standards for
"acceptable" levels of mold in buildings, and the lack
of a definitive correlation between exposure levels and
health effects makes interpreting the data difficult, if
not impossible.
Testing is usually done to compare the levels
and types of mold spores found inside the building
with those found outside of the building or for
comparison with another location in the building. In
addition, air sampling may provide tangible evidence
supporting a hypothesis that investigators have
formulated. For example, air sampling may show a
higher concentration of the same species of mold when
the HVAC is operating than when it has been turned
off. This finding may convince the investigators that
the mold is growing within, and being disseminated by,
the HVAC system. Conversely, negative results may
persuade investigators to abandon this hypothesis and
to consider other sources of mold growth or
dissemination. If you know you have a mold problem,
it is more important to spend time and resources
removing the mold and solving the moisture problem
that causes the moldy conditions than to undertake
extensive testing for the type and quantity of mold.
If you are in doubt about sampling, consult
an industrial hygienist or other environmental
health or safety professional with experience in
microbial investigations to help you decide if
sampling for mold is necessary or useful, and to
identify persons who can conduct any necessary
sampling. Due to the wide difference in individual
susceptibility to mold contamination, sampling
results sampling may have limited application.
However, sampling results can be used as a guide
to determine the extent of an infestation and the
effectiveness of the cleanup. Their interpretation is
best left to the industrial hygienist or other
environmental health or safety professional.
Sampling for mold should be conducted by
professionals with specific experience in designing
mold-sampling protocols, sampling methods for
microbial contaminants, and interpretation of results.
For additional information on air sampling, refer to the
American Conference of Governmental Industrial
Hygienists' document, "Bioaerosols: Assessment and
Control." In addition, sampling and analysis should
follow any other methods recommended by either
OSHA, NIOSH, EPA, the American Industrial
Hygiene Association, or other recognized professional
guidelines. Types of samples can include: air samples,
surface samples, bulk samples, and water samples
from condensate drain pans or cooling towers.
Microscopic identification of the spores/
colonies requires considerable expertise. These
services are not routinely available from
commercial laboratories. Documented quality control
in the laboratories used for analysis of the bulk,
surface, and other air samples is necessary. The
American Industrial Hygiene Association offers
accreditation to microbial laboratories (Environmental
Microbiology Laboratory Accreditation Program
(EMLAP)). Accredited laboratories must participate
in quarterly proficiency testing (Environmental
Microbiology Proficiency Analytical Testing Program
(EMPAT)).
Remediation Equipment
There are various types of equipment useful in
mold assessment and remediation. Some of the
more common items include:
Moisture Meters
Moisture meters measure/monitor moisture
levels in building materials, and may be helpful for
measuring the moisture content in a variety of
building materials following water damage. They also
can be used to monitor the progress of drying
damaged materials. These direct reading devices
have a thin probe that is inserted into the material
to be tested or pressed directly against the surface
of the material. Moisture meters can be used on
materials such as carpet, wallboard, wood, brick, and
concrete.
Humidity Gauges or Meters
Humidity meters can be used to monitor
indoor humidity. Inexpensive (less than $50)
models that monitor both temperature and
humidity are available.
Humidistat
A humidistat is a control device that can be
connected to an HVAC system and adjusted so that
if the humidity level rises above a set point, the
HVAC system will automatically turn on and reduce
the humidity below the established point.
Boroscope
A boroscope is a hand-held tool that allows
users to see potential mold problems inside walls,
ceiling plenums, crawl spaces, and other tight
areas. It consists of a video camera on the end of a
flexible "snake." No major drilling or cutting of dry
wall is required.
HVAC System Filter
High-quality filters must be used in a
HVAC system during remediation because
conventional HVAC filters are typically not
effective in filtering particles the size of mold
spores. Consult an engineer for the appropriate
filter efficiency for your specific HVAC system,
and consider upgrading your filters if necessary. A
filter with a minimum efficiency of 50 to 60% or a
rating of MERV 8, as determined by Test Standard
52.2 of the American Society of Heating,
Refrigerating and Air-Conditioning Engineers,
may be appropriate.
Remember to change filters as appropriate,
especially following any remediation activities.
Remove filters in a manner that minimizes the
reentry of mold and other toxic substances into the
workplace. Under certain circumstances, it may be
necessary to wear appropriate PPE while performing
this task.
How Do You Know When You Have Finished
Remediation/Cleanup?
- You must have identified and completely corrected
the source of the water or moisture problem.
- Mold removal should be complete. Visible mold,
mold-damaged materials, and moldy odors should
no longer be present.
- Sampling, if conducted, should show that the level
and types of mold and mold spores inside the
building are similar to those found outside.
- You should revisit the site(s) after remediation, and
it should show no signs of moldy or musty odors,
water damage, or mold growth.
Conclusion
After correcting water or moisture infiltration,
the prompt removal of contaminated material and
structural repair is the primary response to mold
contamination in buildings. In all situations, the
underlying cause of water accumulation must be
rectified or the mold growth will reoccur. Emphasis
should be placed on preventing contamination through
proper building and HVAC system maintenance and
prompt repair of water damaged areas.
Effective communication with building
occupants is an essential component of all large-scale remediation efforts. The building owner,
management, and/or employer should notify
occupants in the affected area(s) of the presence of
mold. Notification should include a description of
the remedial measures to be taken and a timetable for
completion. Group meetings held before and after
remediation with full disclosure of plans and results can
be an effective communication mechanism. Individuals
with persistent health problems that appear to be
related to mold exposure should see their physicians
for a referral to practitioners who are trained in
occupational/environmental medicine or related
specialties and are knowledgeable about these types
of exposures.
References
American Conference of Governmental Industrial
Hygienists 1999. Bioaerosols
Assessment and Control
http://www.acgih.org
National Apartment Association
http://www.naahq.org
National Institute for Occupational Safety and Health
(NIOSH)
National Multi-Housing Council
http://www.nmhc.org
The Building Owners and Managers Association
International (BOMA)
http://www.boma.org
New York City Department of Health & Mental
Hygiene Bureau of Environmental & Occupational
Disease Epidemiology 2002.
Guidelines on
Assessment and Remediation of Fungi in
Indoor Environments
United States Environmental Protection Agency,
Office of Air and Radiation, Indoor Environments
Division 2001.
Mold Remediation in Schools and
Commercial Buildings. EPA 402-K-01-001
Mold Resources List
Business owners who are concerned about the cost
of professional help can contact the OSHA
Consultation Project Office in their state for free
consultation service. Priority is given to businesses
with fewer than 250 employees at a worksite, with
further consideration given to the severity of the
worksite problem. The Consultation Program can
help the employer evaluate and prevent hazardous
conditions in the workplace that can cause injuries and
illnesses, including mold problems.
The following list of resources includes
information developed and maintained by public
and private organizations. However, OSHA does
not control this information and cannot guarantee the
accuracy, relevance, timeliness, or completeness of
this outside information. Further, the inclusion of these
resources is not intended to endorse any views
expressed, or products or services offered, by the
author of the reference or the organization operating
the service identified by the reference.
An Office Building Occupants Guide to Indoor Air Quality
[Page title updated in 2012]
Biological Pollutants [Page title updated in 2012]
Building Air Quality (BAQ)
[Page title updated in 2012]
Flood Cleanup [Page title and link updated in 2012]
Indoor Air Quality (IAQ) Home Page
IAQ in Large and Commercial Buildings
[Page title updated in 2012]
Creating Healthy Indoor Environments in Schools [Page title updated in 2012]
Mold Resources
Mold Remediation in Schools and Commercial Buildings
U.S. EPA IAQ Information Clearinghouse
(IAQINFO)
Phone: (800)438-4318 or (703)356-4020
Fax: (703)356-5386
Email: iaqinfo@aol.com
Indoor air related documents, answers to Indoor
Air Quality (IAQ) questions, maintains listing of
State IAQ contacts, and regional EPA Contacts.
Air Conditioning Contractors of America (ACCA)
(703)575-4477
http://www.acca.org
Information on indoor comfort products and
services.
American College of Occupational and
Environmental Medicine (ACOEM)
(847)818-1800
http://eserver.acoem.org/physicianlocator/default.cfm
Referrals to physicians who have experience with
environmental exposures.
American Conference of Governmental Industrial
Hygienists, Inc. (ACGIH)
(513)742-2020
http://www.acgih.org
Occupational and environmental health and safety
information.
American Industrial Hygiene Association (AIHA)
(703)849-8888
http://www.aiha.org
Information on industrial hygiene and indoor air
quality issues including mold hazards and legal
issues.
American Society of Heating, Refrigerating and
Air Conditioning Engineers, Inc. (ASHRAE)
(800)527-4723
http://www.ashrae.org
Information on engineering issues and indoor air
quality.
Association of Occupational and Environmental
Clinics (AOEC)
(202)347-4976
http://www.aoec.org
Referrals to clinics with physicians, who have
experience with environmental exposures,
include exposure to mold; maintains a database of
occupational and environmental cases.
Association of Specialists in Cleaning and Restoration
(ASCR)
(800)272-7012 or (410)729-3603
http://www.ascr.org/institutes
Carpet and Upholstery Cleaning Institute,
Mechancial Systems Hygiene Institute, National
Institute of Disaster Restoration, National Institute Rug
Cleaning, Water Loss Institute referrals to
professionals.
American Academy of Allergy, Asthma &
Immunology (AAAAI)
(800)822-2762
http://www.aaaai.org
Physician referral directory, information on allergies
and asthma.
Asthma and Allergy Foundation of American (AAFA)
(800) 7ASTHMA (800)727-8462)
http://www.aafa.org
Information on allergies and asthma.
American Lung Association (ALA)
(800) LUNGUSA (800)586-4872)
http://www.lungusa.org
Information on allergies and asthma.
Allergy and Asthma Network Mothers of
Asthmatics (AANMA)
(800)878-4403 or
(703)641-9595)
http://www.aanma.org
Information on allergies and asthma.
National Institute of Allergy and Infectious Diseases
(NIAID)
(301)496-5717
Information on allergies and asthma.
National Jewish Medical and Research Center
(800) 222LUNG (800)222-5864)
http://www.njc.org
Information on allergies and asthma.
Carpet and Rug Institute (CRI)
(800) 882-8846
http://www.carpet-rug.com
Carpet maintenance, restoration guidelines for
water-damaged carpet, other carpet-related issues.
Centers for Disease Control and Prevention (CDC)
(800)311-3435
Information on health-related topics including asthma
molds in the environment, and occupational health.
CDC is recognized as the lead federal agency for
protecting the health and safety of the American
people at home and abroad. It serves as the national
focus for developing and applying disease prevention
and control, environmental health, and health
promotion and education activities.
Flood Cleanup [Page title and link updated in 2012]
Federal Emergency Management Agency (FEMA)
(800)480-2520
Publications on floods, flood proofing, etc.
University of Minnesota, Department of
Environmental Health and Safety
(612)626-5804
http://www.dehs.umn.edu/iaq/flood.html
Managing water infiltration into buildings.
Indoor Environmental Remediation Board (IERB)
(215)387-4097
http://www.ierb.org
Information on best practices in building remediation.
Institute of Inspection, Cleaning and Restoration
Certification (IICRC)
(360)693-5675
http://www.iicrc.org
Information on and standards for the inspection,
cleaning, and restoration industry.
International Sanitary Supply Association (ISSA)
(800)225-4772
http://www.issa.com
Education and training on cleaning and
maintenance.
MidAtlantic Environmental Hygiene Resource
Center (MEHRC)
(215)387-4096
http://www.mehrc.org
Indoor environmental quality training center giving
courses in building moisture and
biocontamination, and managing and operating
facilities for good IAQ. Extensive courses given
in IAQ.
National Air Duct Cleaners Association (NADCA)
(202)737-2926
http://www.nadca.com
Duct cleaning information.
National Institute of Building Sciences (NIBS)
(202)289-7800
http://www.nibs.org
Information on building regulations, science, and
technology.
National Institute for Occupational Safety and
Health (NIOSH)
(800) 35NIOSH (800)356-4674)
Health and safety information with a workplace
orientation.
National Pesticide Information Center (NPIC)
(800)858-7378
http://npic.orst.edu/
Information on pesticides/antimicrobial chemicals,
including safety and disposal information.
New York City Department of Health, Bureau of Environmental and Occupational
Disease Epidemiology,
Guidelines on
Assessment and Remediation of Fungi in
Indoor Environments
(212)788-4290
Occupational Safety and Health Administration
(OSHA)
(800)321-OSHA (800)321-6742)
Information on worker safety and health,
compliance assistance, laws and regulations, cooperative programs, state programs, statistics,
and newsroom.
Sheet Metal and Air Conditioning Contractors'
National Association (SMACNA)
(703)803-2980
http://www.smacna.org
Technical information on topics such as air
conditioning and air ducts.
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