|NAA Respirator Fit Testing Requirements and Procedures|
Respirator Fit Testing Requirements and Procedures
The OSHA requirement for fit testing respirators has its origins in 29 CFR 1910.134, the Respiratory Protection Standard. A rather ambiguous reference to fit testing is made in 29 CFR 1910.134(e)(5), where employee training is discussed. The passage states, "Training shall provide the men an opportunity to handle the respirator, have it fitted properly, test its facepiece-to-face seal, wear it in normal air for a long familiarity period, and, finally wear it in a test atmosphere."
Missing from 29 CFR 1910.134 are any specifics concerning how this training should be conducted. Many contaminant-specific OSHA standards established after 29 CFR 1910.134, such as Asbestos (29 CFR 1910.1001), Lead (29 CFR 1910.1025), Formaldehyde (29 CFR 1910.1048) and Cadmium (29 CFR 1910.1027) do reference explicit respirator fit guidelines within the respective standards. Rather than provide detailed instructions, 29 CFR 1910.134? states that "Proper selection of respirators shall be made according to the guidance of American National Standard Practices for Respiratory Protection Z88.2-1969."
Within ANSI Z88.2-1969, fit testing procedures are defined and tests are described in exacting detail. It is important to note the ANSI Z88.2 standard has been revised twice since 29 CFR 1910.134 was published. The most recent revision, ANSI Z88.2-1992, has removed fit testing procedures from the standard. It states that a separate standard, ANSI Z88.10, will eventually contain the requirements for acceptable tests. ANSI Z88.2-1992 refers the reader to the protocol listed in the OSHA Asbestos Standard (29 CFR 1910.1001) for fit testing compliance until ANSI Z88.10 is published.
Fit Testing Procedures
There are two types of fit testing procedures: quantitative and qualitative. 29 CFR 1910.1001(g)(4)(ii) of the Asbestos standard states, "For each employee wearing negative pressure respirators, employers shall perform either quantitative or qualitative fit tests." No exclusion is made for disposable dust/mist masks. The Cadmium Standard expands the scope of fit testing to include positive-pressure respirators under 29 CFR 1910.1027(g)(4)(ii). Because of the inclusion of positive-pressure respirators into the Cadmium Standard, it is now prudent to fit test all respirators.
Quantitative fit testing is defined in ANSI Z88.2-1992 as: "A fit test that uses an instrument to measure the challenge agent inside and outside the respirator." This procedure is more precise than the qualitative fit test. It is also performed less commonly because of its complexity. The cost of the required analyzation instrument is also prohibitive. The quantitative test is recommended for work in highly toxic or IDLH (Immediately Dangerous to Life or Health) environments, when facepiece leakage must be minimized.
Presently, the only place OSHA requires a quantitative fit test is in the Cadmium Standard. 29 CFR 1910.1027(g)(4)(iii) states that quantitative fit testing is required for employees who are exposed to airborne concentrations of cadmium that exceed 10 times the permissible exposure limit (PEL). The standard also requires quantitative fit testing for "each employee wearing a tight-fitting, supplied-air respirator, or self-contained breathing apparatus" (29 CFR 1910.1027(g)(4)(iv)).
Along with the analyzation instrument, a challenge agent and a probed respirator (or probe adapter for a standard respirator) are necessary to perform a quantitative fit test. The quantitative fit test protocol is described in detail in Appendix C to both the Asbestos Standard (29 CFR 1910.1001) and Cadmium Standard (29 CFR 1910.1027).
ANSI Z88.2-1992 defines qualitative fit testing as, "A pass/fail test that relies on the subject's response to detect the challenge agent." Because this test relies upon the subjective response of the individual being tested, the reproducibility and accuracy may vary. The qualitative test is more commonly performed because of its simplicity. The necessary testing equipment is also easier to obtain and more economical than quantitative testing equipment.
The three accepted test methods for qualitative fit testing are: isoamyl acetate (more commonly known as banana oil), saccharin solution aerosol, and irritant fume. The test methods all follow essentially the same format. The test method performed will dictate the type of air-purifying element that is used.
The isoamyl acetate or banana oil fit test requires respirators equipped with organic vapor cartridges. The saccharin solution aerosol fit test requires respirators equipped with particulate filters. For applications requiring high-efficiency or HEPA filters, the irritant fume fit test is specified. The saccharin test can be used for a HEPA respirator, but the irritant fume is recommended because the test subject will less likely be able to camouflage a response to the irritant fume. This is important because HEPA respirators are generally used for protection from highly toxic particles, situations where the facepiece-to-face is crucial.
Complete instructions for all qualitative test procedures are located in Appendix C of the Asbestos Standard (29 CFR 1910.1001)
Under part 9.1.4 of ANSI Z88.2-1992 it states, "A respirator fit test shall be carried out for each wearer of a tight-fitting respirator at least every 12 months." The same is true for compliance with the Cadmium and Formaldehyde Standards. Other contaminant-specific standards, such as Asbestos and Lead, require fit testing every six months. In addition, fit testing should be repeated immediately if the subject experiences a weight change of 20 pounds or more, has significant dental changes, or has reconstructive surgery or a facial disfigurement (scarring) All of these instances could affect the facepiece seal.
The employer must ensure that each respirator wearer is medically cleared to wear a respirator. The ARS OMSP Program is used to complete this function. In addition, secure a copy of the clearance for your safety file.
The employer is responsible for recording the results of fit testing. Part 9.4 of ANSI Z88.2-1992 identifies what must be included in the fit test records. The standard does not, however, specify the length of time for which these records must be retained. Insurance carriers often have requirements concerning retention of employee training and health records. They should be consulted for guidance in this area.
Contaminant-specific standards will often state the length of time their respective records must be retained. For example, the Asbestos Standard (29 CFR 1910.1001) requires fit testing records to be held for three years.
Fit testing should not be confused with a respirator fit check. ANSI Z88.2-1992 defines a fit check as, "A test conducted by the wearer to determine if the respirator is properly sealed to the face."
It's recommended that a fit check be performed each time the respirator is donned or adjusted. The fit check is a quick method to determine if the respirator is properly sealed to the face.
Under part A.6 of ANSI Z88.2-1992, procedures for conducting a fit check are described. The two most commonly performed methods are the positive- and negative-pressure tests. The positive-pressure check requires the wearer to cover the exhalation valve of the tight-fitting respirator (placing the palm over the valve is usually sufficient) and exhale. If there is no indication of air escaping, the fit is considered satisfactory. During a negative-pressure fit check, the inlet opening of the respirator's cartridges or filters are covered. The wearer then inhales. If no leakage is detected, the facepiece seal is satisfactory.
Another method for fit checking requires exposing the wearer to a challenge agent (isoamyl acetate, saccharin mist, irritant fume). If the wearer does not detect the challenge agent, the fit check is successful. This method is the only way respirators without valves can be effectively tested. The challenge agent selected will depend on the type of air-purifying element being used.
It is important to note that a fit check is NOT a substitute for a quantitative or qualitative fit test. Fit tests follow detailed, step-by-step guidelines; fit checks do not.
Lab Safety has the products you need to keep your workers safe and comply with current regulations. Please refer to the Books and Respirators sections of your Lab Safety Supply General Catalog for details.
Sources for More Information
29 CFR 1910.134, Respiratory Protection Standard.
29 CFR 1910.1001, Asbestos Standard
29 CFR 1910.1025, Lead Standard
29 CFR 1910.1048, Formaldehyde Standard
29 CFR 1910.1027, Cadmium Standard
ANSI Z88.2-1992, American National Standard Practices for Respiratory Protection
American National Standards Institute
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New York, NY 10036
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Please Note: The information contained in this handout is intended for general training purposes only. It is not a substitute for review of the applicable government regulations and standards.