A wide variety of toxic airborne organic vapors, gases, spray mists, fumes and dusts are
produced by materials used in the visual arts, theater and conservation.
Ventilation should be the
first line of defense against these airborne materials. In certain circumstances, ventilation is not
adequate and respiratory protection is necessary,
OSHA permits the use of respirators only when effective engineering controls are not feasible,
or while they are being instituted.
In fact, proper use of respirators takes a lot more effort and
knowledge than many people assume.
Employees wearing respirators come under OSHA's respirator standard. This standard (29
CFR 1910.134) has just been updated. The revised standard became effective April 8, 1998, with
employers having to be in complete compliance by October 5, 1998.
The revised standard can be
found on CSA's web site (http://artswire.org:70/1/csa) in the Precautions subdirectory. The
revised standard has several new or enlarged requirements:
* a written plan with work-site specific procedures;
* a hazard evaluation to determine respiratory hazards and work conditions in order to help in
respirator selection (compliance date September 8, 1998);
* medical evaluations to determine the ability of employees to wear a particular respirator;
* fit testing of tight-fitting respirators;
* training in the safe use of respirators; and
* regular respirator program evaluations.
OSHA requires employers to develop and implement a written respiratory protection program
with work-specific procedures and procedures for respirator use.
The program must be
administered by a trained administrator, and must include the following features.
1. Whenever respirators are necessary to protect health or whenever an employer requires
wearing of respirators, there must be a written respiratory protection program with the following
* procedures for selecting respirators;
* medical evaluation of employees required to wear respirators;
* fit-testing procedures for tight-fitting respirators;
* procedures for proper use of respirators in routine and emergency situations;
* procedures and schedules for maintenance of respirators;
* procedures for proper functioning of atmosphere-supplying respirators;
* training of employees in hazards and proper use of respirators; and
* procedures for regularly evaluating the effectiveness of the program.
2. If respirator use is not required:
* An employer may provide employees with respirators or allow employees to use their own
respirators, if the employer determines such respirator use will not create a hazard. If voluntary
respirator wearing is allowed, then the employer must provide the information in Appendix D of
the respirator standard to the respirator user;
* An employer must have a written respirator program that includes medical evaluation of ability
to wear a respirator and adequate maintenance of the respirator. An exception is when an
employee voluntarily wears a filtering facepiece (dust mask), whether provided by the employee
or employer. However the employer must still make sure the dust mask is not a hazard to the
wearer and is not dirty or contaminated.
3. An employer shall designate a program administrator who is qualified by training or experience
to administer the program.
4. Employers shall provide respirators, training, and medical evaluations at no cost to the
Atmosphere-supplying respirators provide a source of clean air from compressed air tanks or
compressors. Examples are supplied air (airline) respirators and self-contained breathing
For situations involving oxygen deficiency or that are immediately dangerous
to life or health (IDLH), only full-facepiece pressure demand SCBA certified by NIOSH for a
minimum service life of 30 minutes, or a full facepiece pressure demand airline respirator with
auxiliary self-contained air supply is acceptable.
Pressure demand or positive pressure respirators
are respirators in which there is always a positive air pressure inside the facepiece so that
contaminated air cannot leak into the facepiece.
The source of air for atmosphere-supplying respirators can be compressed or liquid oxygen or
Compressed or liquid oxygen must meed the US Pharmacopoeia requirements
for medical or breathing oxygen. Compressed air must meet the specifications for Type I-Grade D
breathing air: 19.5 - 23.5 % oxygen, less than 5 mg/cu.m. of hydrocarbons, less than 10 ppm
carbon monoxide, less than 1000 ppm carbon dioxide, and no noticeable odors.
OSHA has other
requirements for cylinders.
Since the use of supplied air respirators is more complicated than air purifying respirators, it is
imperative that people wearing these have adequate and training in their use and practice with
them on a regular basis.
Air-purifying respirators remove contaminants from the air in a given location in a variety of
ways, including filtering particulates from the air, absorbing the contaminant, or chemically
reacting with the contaminant.
The air is pulled into the face-piece by lung power, which creates
a negative pressure inside the face-piece during inhalation. Thus if the fit is not perfect,
contaminants can leak into the face-piece because of this negative pressure.
Air-purifying respirators come in two types: gaseous and particulate.
There can also be
combinations of the two. Gaseous types contain cartridges for organic vapors (e.g. solvent
vapors), ammonia, and acid gases (e.g. for chlorine bleach, sulfur dioxide, hydrogen chloride). In
the past, particulate filters included ones for paint spray, dusts and mists (DM); dusts, mists and
fumes (DMF, e.g. for welding fumes); and high efficiency (HEPA) filters.
In 1995, NIOSH published revised standards for particulate respirators.
The new regulation
provides for nine classes of filters: three levels of filter efficiency, each with three categories of
resistance to filter efficiency degradation from oil. The three levels of filter efficiency are 95%,
99%, and 99.97%. The three categories of resistance to filter efficiency degradation are labeled N
(not resistant to oil) , R (resistant to oil for a limited time), and P ( oil-proof. ). N95 and N99
filters outperform DM and DMF filters.
Air-purifying respirators cannot be used in oxygen-deficient atmospheres, in IDLH situations,
or for very high concentrations of contaminants. They also should not be used for chemicals with
poor warning properties (when air concentrations at or above the recommended exposure levels
create no observable odor, irritation or taste) because there is no way to detect when the cartridge
is no longer removing the contaminants. Examples include methyl alcohol, nitrogen dioxide,
isocyanates, and carbon monoxide.
Air-purifying respirators should also not be relied upon to
give adequate protection against cancer-causing chemicals (carcinogens) because they are not
100% efficient and do allow some contaminants to penetrate through the respirator (see section
below on protection factors). Finally, air-purifying respirators are not to be used for abrasive
blasting because this type of respirator is not approved for very high levels of particulates (see
protection factors below).
Powered air-purifying respirators (PAPRs)
PAPRs actually come under the classification of air-purifying respirators. They differ, however,
in that the air is pumped through the cartridge or filter so that there is always a positive pressure
inside the respirator face-piece.
This reduces a major disadvantage of air-purifying respirators
which create a negative pressure inside the face piece. The same restrictions applying to
air-purifying respirators apply to powered air-purifying respirators. In addition they are only
approved for particulates, although there are also cartridges for gaseous contaminants.
there have been studies indicating that they do not provide as great a protection factor as
Respirator face-pieces come in a variety of types and sizes. These include:
* hoods, which cover the entire head and shoulders;
* full-facepiece types, (typified by the classic "gas mask", and required for protection against eye
* half-facepiece types which cover mouth, nose, and chin;
* quarter-facepiece types, covering the mouth and nose; and
* filtering facepieces (dust masks).
The revised OSHA standard defines filtering facepieces as a negative pressure air-purifying
particulate respirator with a filter as an integral part of the facepiece or with the entire facepiece
consisting of the filtering medium. These dust masks do not have to have full written respirator
Respirators must be selected for the particular contaminants, their physical state, and exposure
conditions that will be encountered by the individual wearing the respirator.
The revised OSHA
respirator standard requires that employers evaluate respiratory hazards in the workplace and
exposure conditions in order to assist in respirator selection. (This must be completed by
September 8, 1998.) If the employer can't identify or reasonably estimate the level of exposure to
a contaminant, the employer shall consider the atmosphere to be IDLH (immediately dangerous to
life or health).
Table 7-1 is a general protocol for determining the allowable types of respirators for a given
contaminant and conditions. Table 7-2 is a more specific selection chart for types of filters and
cartridges for various art processes.
At high concentrations of toxic contaminants, air-supplied
respirators might become necessary instead of air-purifying types.
Different types of
respirators vary in the degree of efficiency with which they can protect. To properly select a
respirator, you need to know the actual concentration of the contaminant in the work area, the
Threshold Limit Value (or OSHA Permissible Exposure Limit) of the contaminant, and the rated
Protection Factor of the various types of respirators.
Hazard Respirator Type
- Combination Airline and auxiliary
- IDLH * - Positive Pressure SCBA
- Positive pressure airline respirator
plus auxiliary SCBA
- Not IDLH - Air line respirator
- Chemical cartridge respirator
Particulate - Dust, mist or fumes respirator
- Airline respirator
- Abrasive blasting respirator
Gaseous and Particulate
- IDLH - Positive pressure SCBA
- Positive pressure airline
respirator plus auxiliary SCBA
- Not IDLH - Airline respirator
- Chemical cartridge respirator with
with special filter
* IDLH Immediately dangerous to life or health
The Protection Factor of a respirator is defined as the concentration outside the respirator
divided by the concentration inside the respirator.
These protection factors are developed from
laboratory studies. Table 7-3 gives the Protection Factors for a variety of respirators based on
recommendations from NIOSH.(OSHA will be issuing Protection Factors in the future).
obtain the maximum concentration of the contaminant for which you can use a given respirator by
multiplying the Protection Factor for that respirator by the recommended exposure level for the
contaminant of concern. If the actual concentration is higher than the calculated maximum
concentration, then you need to select a respirator with a higher Protection Factor.
For example, suppose someone is exposed to xylene, which has a Threshold Limit Value of
100 ppm. The standard half-face respirator with organic vapor cartridges has a Protection Factor
of 10. Therefore, for xylene, the maximum concentration against which this respirator can be
used is 1000 ppm. If the actual concentration is greater than 1000 ppm, then a full-face respirator
or a supplied-air respirator would be needed.
If the concentration of the substance is unknown and can not be estimated, particularly if it is
one that can be immediately dangerous to life or health, then a positive-pressure SCBA type or
positive-pressure demand airline respirator with emergency SCBA should be used. This would
apply, for example, in many spill situations.
In some cases, cartridges for gaseous contaminants have limitations for exposure
concentrations not related to the face-piece. In such instances, the most protective respirator
should be used.
Before requiring an employee to be fit tested for a respirator, a medical evaluation must be
provided to determine the ability of the employee to wear a respirator since respirators put an
extra strain on the heart and lungs.
OSHA does not require a medical examination; at the
minimum, the medical evaluation can be done by a questionnaire found in Appendix C of the
The evaluation must be performed by a physician or other licensed health care
professional qualified to do the evaluation. The OSHA standard has further requirements on what
information must be provided to the health care professional and what information they can
divulge to the employer.
Persons with heart or lung diseases such as arrhythmias, asthma, emphysema, and chronic
bronchitis may be limited in their ability to wear a particular type of respirator.
factors that could limit respirator use include anemia, hemophilia, poor eyesight or hearing (i.e.
not being able to detect warnings), lack of proper use of fingers or hands, and claustrophobia. In
cases where a medical condition would limit the use of negative-pressure air-purifying respirators,
the employer must provide a powered air-purifying respirator if the health professional finds the
employee can use one.
Additional medical evaluations must be done if an employee reports symptoms related to his or
her ability to wear a respirator, if the health care provider or supervisor or respiratory program
administrator indicates the need, or if there is a change in workplace conditions that might result
in an increased physiological strain on the employee.
If a respirator with a tight-fitting facepiece does not fit properly, then it is not serving its
In order to fit, there must be an adequate seal between the face-piece and the
wearer's face. Anything interfering with this seal can allow inward leakage of contaminants.
There are a variety of factors affecting the fit of a respirator, including the model and size of the
face-piece, facial characteristics, and eyeglasses.
No two people have the same size and shape of
face. Similarly there are variations in shape of respirator face-pieces between the different models
of respirators. As a result, it cannot be expected that one size or model of respirator would fit
Until a few years ago, respirators were designed to fit men only, and women and
others with small faces found it impossible to get a proper fit with a respirator. Today most major
respirator manufacturers make a variety of models and sizes. It is therefore advisable, and is
required by OSHA, to provide a variety of makes and sizes available to be certain of a proper fit.
Beards, sideburns or other facial hair between the face-piece and the skin will prevent you from
obtaining a proper respirator to face seal. Many men who shave regularly can even find difficulty
in getting a proper fit if they have a heavy growth during the day. In some instances it is
necessary to shave just before putting on the respirator.
In addition facial scars, missing teeth, and
a broken nose can prevent a proper fit.
Eyeglasses can also prevent a proper fit if the temple bars of eyeglasses interfere with the seal of
the respirator. Changing eyeglass styles can often help. Another solution is to mount corrective
lenses inside a full-face respirator.
OSHA requires annual fit testing to determine if a respirator with a tight-fitting facepiece fits
properly. Employees must also be fit tested if a different respirator facepiece is used, or if there is
any question about the fit of the respirator. If the employee notifies the employer that the fit is
unacceptable (even after passing a fit test) then the employee shall be given a reasonable
opportunity to select another respirator and be retested.
There are two basic types of fit tests: quantitative and qualitative. Quantitative fit testing
involves exposing the respirator wearer to an atmosphere of some agent such as corn oil and
measuring the concentration of this agent both inside and outside the respirator.
This is the best
method but is expensive.
Qualitative fit testing involves exposing the respirator wearer to an agent which can be detected
by irritation, odor or taste. Examples of approved qualitative fit testing agents include isoamyl
acetate (banana oil), irritant smoke, saccharin mist, and Bitrex.
The isoamyl acetate requires an
organic vapor cartridge and the irritant smoke, saccharin and Bitrex require a particulate filter.
Qualitative fit testing may only used to test negative pressure air-purifying respirators that must
achieve a fit factor of 100 or less.
The following are the general steps required by OSHA for qualitative fit testing. The entire
protocol can be found in the mandatory Appendix A of the respirator standard.
1. The person to be tested shall be allowed to select the most acceptable respirator from a variety
2. Prior to selection, the person shall be shown how to put on and adjust a respirator.
3. The selected respirators is put on and worn for at least 5 minutes to assess comfort.
4. The adequacy of the fit shall be checked using listed criteria.
5. The test subject shall conduct
either a positive or negative-pressure seal check as described in Appendix B-1.
6. The fit test procedure shall be described, including exercises to be performed.
7. The fit test will be performed wearing any other personal protective equipment that would be
normally worn and which could affect respirator fit.
8. For qualitative fit tests, a threshold
sensitivity test will be performed to determine if the person can detect the odor, taste or other
response used to indicate a poor fit.
9. The person shall conduct the following 1-minute exercises while wearing the respirator in the
fit testing atmosphere:
* normal breathing;
* deep breathing;
* turning head side to side;
* moving head up and down;
* bending over; and
* repeat of normal breathing.
10. If a person fails a fit test with a given respirator, the procedure is repeated with a different
Records of fit tests must be kept until the next fit test.
OSHA requires employers to establish procedures for the proper use of respirators.
* prohibiting conditions that would interfere with the facepiece seal. Employers shall not allow
employees with tight-fitting facepieces to be worn by employees who have facial hair that comes
between the sealing surface of the facepiece and the face or have any other condition that would
interfere with the seal or valve function.
* Employers shall ensure that corrective glasses or goggles or other personal protective
equipment worn by employees does not interfere with the facepiece seal.
* Employees wearing respirators with tight-fitting facepieces must perform a user seal check each
time they wear the respirator, as described in Appendix B-1 (or approved manufacturer
Ongoing surveillance of the workplace conditions to determine if they may affect respirator
* Employers shall ensure that employees leave respirator use area to
1) wash their faces as needed
to prevent eye or skin irritation;
2) if they detect vapor or gas breakthrough, changes in breathing
resistance or leakage; and
3) to replace filers, cartridges or canisters.
* Employers must have proper emergency procedures for use of respirators in IDLH
One of the major disadvantages of air-purifying respirators is that the cartridges become
saturated with the gaseous contaminant and breakthrough of the contaminant occurs into the
The revised OSHA standard requires that air-purifying respirators be equipped with
end-of-service indicators certified by NIOSH for the contaminant or that the employer implement
a change of cartridge schedule based on objective data.
The data relied on shall be included in the
respirator program. In the absence of air sampling data to help determine when to change
cartridges, the respirator manufacturer should be consulted. In any case, change cartridges if odor
breakthrough is detected.
With filter cartridges, the more particulates collected on the filter, the more efficient the filtering
action. Particulate filters should get changed whenever it becomes difficult to breathe through
Maintenance and Care of Respirators
OSHA requires employers to provide for cleaning and disinfecting, storage, inspection and
repair of respirators used by employees.
* Appendix B-2 of the respirator standard specifies cleaning and disinfection procedures.
Respirators used by one person shall be cleaned and disinfected as needed to maintain them in a
sanitary condition. Respirators worn by more than one person shall be cleaned and disinfected
before being worn by different individuals. Emergency respirators shall be cleaned and disinfected
after every use.
* Respirators shall be stored to protect them from damage, contamination, lights, temperature
* Respirators used routinely shall be inspected before each use and during cleaning. Inspections
must include a check of respirator function, tightness of connections, condition of various parts
including valves, straps, facepiece, etc.
There are special procedures for emergency and
* Defective respirators must be repaired before being used. Repairs must be done by trained
Employees required to wear respirators must be trained before being required to use a
respirator, and at least annually thereafter. The training must be understandable by the employees
and employers must demonstrate that employees know at least the following:
* why the respirator is needed and the how improper fit, use or maintenance can affect its
* limitations and capabilities of the respirator;
* what to do in emergency situations, including cases of respirator malfunction;
* how to inspect, put on and remove, and check the seal of the respirator;
* how to recognize medical signs that may limit or prevent respirator use;
* the general requirements of the OSHA respirator standard.
Employees voluntarily wearing respirators must be given the information in Appendix D.
Employers must conduct regular evaluations of the workplace to ensure that the written
respiratory program is being properly implemented. This shall include consulting employees about
the effectiveness of the program. Factors to be assessed include:
* respirator fit;
* appropriate respirator selection;
* proper respirator use under existing workplace conditions; * proper respirator maintenance.
OSHA regulations only apply to employees, and do not cover students (unless they are
working for the Art Department). However, in order to protect students, it is good practice to
use the same procedures for respirator use with students as is required for employees.
I would not recommend that students ever be in situations where atmosphere-supplying
respirators are required for reasons of the complexity of the equipment, the danger of accidents,
and possible liability in case of accidents.
American National Standards Institute. American National Standard for Respiratory Protection -
Protection During Fumigation ANSI Z88.3-1983. New York (1983).
American National Standards Institute. American National Standard Practices for Respiratory
Protection. ANSI Z88.2-1980. New York (1980).
National Institute for Occupational Safety and Health. A Guide to Industrial Respiratory
Protection DHEW (NIOSH) #76-189, Government Printing Office, Washington, DC (1976).
National Institute for Occupational Safety and Health. NIOSH Certified Equipment List As of
October 1, 1987. DHEW (NIOSH) #88-107. Government Printing Office, Washington, DC
(1988). Updated regularly.
National Institute for Occupational Safety and Health. NIOSH Respirator Decision Logic.
DHEW (NIOSH) #87-108. Government Printing Office, Washington DC (1987).
National Institute for Occupational Safety and Health.
Respiratory Protection: An Employers Manual, DHEW (NIOSH) #78-138A. Government
Printing Office, Washington, DC (1978). National Institute for Occupational Safety and Health.
Respiratory Protection: A Guide for the Employee, DHEW (NIOSH) #78-138B. Government
Printing Office, Washington, DC (1978). Occupational Health and Safety Products Division/3M,
Administrative Respiratory Protection Program. 3M Center, St. Paul, Minnesota.
Occupational Safety and Health Administration. Occupational Safety and Health Standards for
General Industry - Respiratory Protection. 29 CFR 1910.134. Government Printing Office,
Washington, DC (1981).
This data sheet was made possible with the assistance of public funding from the National
Museum Act and the Museum Aid Program of the New York State Council on the Arts.
(c) Center for Safety in the Arts 1986, 1989, 1998