5.3 Respiratory Protection Programs & Fit Testing (29 CFR 1910.134)

5.3 Respiratory Protection Programs & Fit Testing (29 CFR 1910.134)

Introduction to Respiratory Protection

In environments where engineering controls are not feasible, or while they are being installed, respiratory protection is necessary to protect employees from inhaling harmful dusts, fogs, fumes, mists, gases, smokes, sprays, or vapors. OSHA's Respiratory Protection standard, 29 CFR 1910.134, is one of the most comprehensive and frequently cited health standards in General Industry. It outlines the strict requirements for implementing a written program, conducting medical evaluations, performing annual fit testing, understanding assigned protection factors, and selecting the appropriate class of respirator.

The Written Respiratory Protection Program

Whenever respirators are required in the workplace, the employer must establish and implement a written respiratory protection program with worksite-specific procedures. The program must be updated as necessary to reflect changes in workplace conditions that affect respirator use. The employer must designate a qualified program administrator to run the program and evaluate its effectiveness regularly.

A compliant written program must include nine mandatory elements:

1. Procedures for selecting respirators for use in the workplace.
2. Medical evaluations of employees required to use respirators.
3. Fit testing procedures for tight-fitting respirators.
4. Procedures for proper use of respirators in routine and reasonably foreseeable emergency situations.
5. Procedures and schedules for cleaning, disinfecting, storing, inspecting, repairing, discarding, and otherwise maintaining respirators.
6. Procedures to ensure adequate air quality, quantity, and flow of breathing air for atmosphere-supplying respirators.
7. Training of employees in the respiratory hazards to which they are potentially exposed during routine and emergency situations.
8. Training of employees in the proper use of respirators, including putting them on and taking them off, any limitations on their use, and their maintenance.
9. Procedures for regularly evaluating the effectiveness of the program.

Voluntary Use Exception: If the employer determines that respirator use is not required, but allows employees to use respirators voluntarily (such as filtering facepiece "dust masks"), the employer must provide the employee with the information contained in Appendix D of 29 CFR 1910.134. However, if the voluntary respirator is an elastomeric respirator or a powered air-purifying respirator (PAPR), the employer must still establish elements of the written program to ensure the user is medically fit and that the respirator is cleaned and stored properly.

Medical Evaluations (PLHCP)

Wearing a respirator places a physical burden on the human body. It increases the resistance to breathing, can cause carbon dioxide build-up inside the facepiece, and adds weight and heat stress, which can place significant strain on the cardiovascular and pulmonary systems.

Therefore, 29 CFR 1910.134(e) requires that the employer provide a medical evaluation to determine the employee's ability to use a respirator before the employee is fit tested or required to use the respirator in the workplace.

• The evaluation must be performed by a Physician or Other Licensed Health Care Professional (PLHCP).
• The employer must use the OSHA medical questionnaire (found in Appendix C of the standard) or conduct an equivalent medical examination.
• The PLHCP will provide a written recommendation regarding whether the employee is medically fit to wear a respirator and if there are any limitations (e.g., restricted to wearing a PAPR instead of a negative-pressure respirator).
• Re-evaluations: The employer must provide additional medical evaluations if an employee reports medical signs or symptoms related to respirator use, if the PLHCP, supervisor, or program administrator determines it is necessary, or if workplace conditions change in a way that increases the physical burden on the employee.

Fit Testing: Qualitative vs. Quantitative

Fit testing is required for all tight-fitting respirators (both negative and positive pressure). A tight-fitting respirator must have an effective seal against the user's face to prevent contaminated air from bypassing the filter or cartridge.

• Timing: Fit testing must be conducted prior to initial use of a respirator, and at least annually (every 12 months) thereafter. It must be repeated if the employee has physical changes that could affect the facepiece seal, such as dental work, facial surgery, significant cosmetic changes, or a body weight change of 10% or more.
• No Facial Hair: Tight-fitting respirators cannot be worn by employees with facial hair (such as beards, long mustaches, or stubble) that passes between the sealing surface of the facepiece and the face, or that interferes with valve function.

There are two approved methods of fit testing:

1. Qualitative Fit Testing (QLFT): A pass/fail test method that relies on the user's sensory detection (taste, smell, or mild irritation) of a test agent. If the user detects the test agent inside the mask, the fit is inadequate. Common agents include:
   • Isoamyl acetate (banana oil): Tests for organic vapor respirators.
   • Saccharin: A sweet aerosol spray.
   • Bitrex: A bitter-tasting aerosol spray.
   • Irritant smoke (stannic chloride): Causes voluntary coughing (requires caution). QLFT is simple and inexpensive but is subjective and can only be used to fit test negative-pressure air-purifying respirators that must achieve a fit factor of 100 or less (e.g., half-mask elastomeric or filtering facepiece respirators).
2. Quantitative Fit Testing (QNFT): An assessment that uses an instrument to numerically measure the amount of leakage into a respirator. It does not rely on human senses. The instrument (like a Portacount) compares the concentration of particles in the ambient air outside the mask to the concentration of particles inside the mask to calculate a numerical "Fit Factor."
   • For a half-mask respirator, a fit factor of at least 100 must be achieved.
   • For a full-facepiece respirator, a fit factor of at least 500 must be achieved. QNFT is mandatory for full-facepiece negative-pressure respirators if they are to be used in atmospheres where a protection factor greater than 10 is required.

Assigned Protection Factors (APF) & Maximum Use Concentration (MUC)

The Assigned Protection Factor (APF) is the level of respiratory protection that a respirator is expected to provide when worn correctly. Standard APF values established by OSHA include:

The APF is used to calculate the Maximum Use Concentration (MUC) for a specific workplace hazard. The MUC is the maximum atmospheric concentration of a hazardous substance from which an employee can be expected to be protected by a class of respirator.

The formula is: $\text{MUC} = \text{APF} \times \text{PEL}$

Calculation Example: If a chemical has an OSHA PEL of 10 parts per million (ppm), and a worker wears a quantitatively fit-tested full-facepiece APR (APF = 50), the MUC is: $\text{MUC} = 50 \times 10 \text{ ppm} = 500 \text{ ppm}$

If the concentration in the workplace exceeds 500 ppm, this class of respirator is inadequate, and a higher-performing respirator (such as an SCBA or PAPR with a higher APF) must be selected. Note: The MUC is also limited by the chemical's Immediately Dangerous to Life or Health (IDLH) value or the cartridge's capacity limits.

Supplied-Air (SAR/SCBA) vs. Air-Purifying Respirators (APR)

Respirators are broadly divided into two categories based on how they provide clean air:

1. Air-Purifying Respirators (APR): These devices draw ambient air through a filter, cartridge, or canister to remove particles, gases, or vapors. They can be negative-pressure (relying on the user's lung power) or positive-pressure (PAPR, which uses a blower).
   • CRITICAL LIMITATION: APRs do not supply oxygen. They only filter the air that is already in the room. They must never be used in oxygen-deficient atmospheres (less than 19.5% oxygen) or in atmospheres that are Immediately Dangerous to Life or Health (IDLH).
2. Atmosphere-Supplying Respirators: These devices deliver clean breathing air from a source independent of the ambient atmosphere.
   • Supplied-Air Respirators (SAR): Also known as airline respirators. Clean air is delivered via a hose from a remote compressor or bank of high-pressure cylinders. The maximum allowable hose length is 300 feet. A critical safety requirement is that if the airline is used in an IDLH atmosphere, the user must wear an auxiliary self-contained air cylinder (often a 5- or 10-minute escape bottle) to provide air in case the primary supply line is cut or fails.
   • Self-Contained Breathing Apparatus (SCBA): The user carries their own breathing air supply in a high-pressure cylinder (typically 30- to 60-minute capacity). SCBAs operate under positive pressure (pressure-demand) to ensure that any facepiece leakage is outward. SCBAs are mandatory for entry into unknown or IDLH atmospheres, and for firefighting.