What does OSHA 29 CFR 1910.134 require for respiratory protection programs?

Short answer: OSHA 29 CFR 1910.134 is the general industry respiratory protection standard. It requires employers to establish a written respiratory protection program whenever respirators are used — whether required or voluntarily worn — with specific provisions covering NIOSH-approved respirator selection, medical evaluation, annual fit testing, user seal checks, cartridge change-out schedules, training, and recordkeeping. The standard was substantially revised in 1998 and remains the foundational regulatory document that all other OSHA respiratory protection requirements reference or incorporate. Construction employers comply with 1910.134 through 29 CFR 1926.103, which defers directly to it.

OSHA 29 CFR 1910.134: The Respiratory Protection Standard (2026 Guide)

Every respiratory protection program in the United States — across general industry, construction, maritime, and federal contractor operations — is built on the framework established by 29 CFR 1910.134. This standard, promulgated in its current form in January 1998 after more than two decades of development, defines the legal minimum for every element of a respiratory protection program: the written program structure, the process for selecting NIOSH-approved respirators matched to specific hazards, the medical evaluation required before a worker wears a required respirator for the first time, the annual fit testing obligation, the user seal check protocol, cartridge change-out documentation, and the training and recordkeeping that holds the program together.

This guide is for EHS managers, safety directors, plant managers, and anyone responsible for building or auditing a respiratory protection program. It covers the full 1910.134 section structure, the Assigned Protection Factor (APF) table and Maximum Use Concentration (MUC) calculation used for respirator selection, each mandatory appendix, the most commonly cited compliance failures, and a step-by-step worked example that walks through implementing a compliant program for a manufacturing maintenance operation with both organic vapor and particulate hazards.

Scope of this standard.
1910.134 applies to all general industry employers covered by OSHA's Part 1910 standards whenever respirators are used in the workplace. Construction employers comply through 29 CFR 1926.103, which requires compliance with all of 1910.134. Maritime employers comply through 29 CFR 1915.154 and 1917.92, which also incorporate 1910.134 by reference. Federal contractors covered by OSHA standards must comply with 1910.134 applicable to their industry sector. The standard has 13 operative sections (§§1910.134(a)–(m)) plus five mandatory appendices (A–D, with Appendix E informational).

Part 1 — What is OSHA 29 CFR 1910.134 and how did it develop?

29 CFR 1910.134 is located in OSHA's General Industry Safety and Health Standards, Title 29, Code of Federal Regulations, Part 1910, Subpart I (Personal Protective Equipment). The standard traces its origins to OSHA's initial standards set in 1971, which incorporated existing national consensus standards for respirators from that era. For more than 25 years, the 1971 respiratory protection standard remained largely unchanged while respirator technology, industrial hygiene practice, and understanding of occupational respiratory disease advanced substantially.

The 1998 revision — which remains the operative version today — overhauled the standard in several fundamental ways: it introduced the written program requirement as the administrative backbone, added formal medical evaluation requirements for required-use programs, established the fit testing obligation as a specific annual requirement with accepted protocol methods, introduced the APF table as a quantitative selection tool, and addressed voluntary use specifically. The 1998 revision drew heavily on the consensus standard ANSI/AIHA Z88.2-1992 — see the ANSI/ISEA Z88.2 respiratory protection program standard guide for the relationship between the two documents.

A significant post-1998 amendment was the 2006 Final Rule on Assigned Protection Factors, which formally added the APF table to 1910.134(d)(3)(i)(A). Prior to 2006, APF values existed in OSHA guidance documents but were not part of the binding regulatory text. The 2006 rule codified the APF table and the MUC calculation method, establishing them as mandatory elements of respirator selection rather than recommended practice.

Part 2 — When does 1910.134 apply? Required use vs. voluntary use

1910.134(a)(1) establishes the basic permissible practice: in the workplace where feasible engineering and administrative controls do not adequately reduce employee exposure to harmful levels, respirators shall be used. The standard applies in two distinct scenarios with very different compliance obligations:

Required use

Respirators are required when: (a) engineering controls (ventilation, substitution, enclosure) cannot reduce employee exposure to or below the applicable OSHA PEL or action level; or (b) a substance-specific standard mandates respiratory protection at or above a specified concentration threshold. When respirators are required, the full 1910.134 program applies: written program, NIOSH-approved equipment, medical evaluation, fit testing, training, and recordkeeping. Employers cannot require workers to provide their own respirators for required-use programs — the employer must provide them at no cost.

Voluntary use

When a respirator is not required by OSHA but an employee wants to wear one, voluntary use provisions apply under §1910.134(c)(2):

• Filtering facepieces only (e.g., N95 disposables): The employer must provide the user with the information in Appendix D — a one-page document explaining the respirator's limitations and the importance of proper use. No written program, medical evaluation, or fit testing is required.
• Any other respirator (half-face APR, full-face APR, PAPR, etc.): The employer must implement a written program per §1910.134(c), ensure the respirator does not itself create a hazard, and conduct medical evaluations. Fit testing is required for tight-fitting facepieces. The full administrative infrastructure applies.

The practical implication: allowing workers to keep half-face APRs in their toolboxes for "whenever they want to use one" without a written program, medical evaluations, and fit test records is a 1910.134 violation — even if the task does not require respiratory protection. The program obligation follows the equipment type, not the hazard level.

Part 3 — The written respiratory protection program — §1910.134(c)

The written respiratory protection program (WRPP) is the administrative backbone of every 1910.134-compliant program. §1910.134(c)(1) requires the WRPP to include worksite-specific procedures for each of the following elements:

The WRPP must be worksite-specific — a generic template downloaded from a safety organization does not satisfy 1910.134(c)(1) unless it has been customized to identify the specific hazards present, the specific NIOSH-approved equipment in use, and the procedures applicable to that workplace. The WRPP must be available to all employees covered by the program and to OSHA inspectors on request. A program administrator designated under §1910.134(c)(1) must be suitably trained to administer the program. For guidance on program administrator qualification criteria beyond the 1910.134 minimum, see the ANSI/ISEA Z88.2 guide.

Part 4 — Respirator selection: APF table, MUC, and NIOSH approval — §1910.134(d)

§1910.134(d) establishes three parallel selection requirements that must all be satisfied simultaneously: the respirator must be NIOSH-approved, it must provide a level of protection matched to the hazard through the APF and MUC framework, and it must be appropriate for the specific work environment and user characteristics.

NIOSH approval requirement

§1910.134(d)(1)(ii) requires that all respirators used in required programs be NIOSH-certified. This means the respirator must carry a valid TC-84A (or equivalent) approval number on the facepiece, cartridge, and packaging, and that approval must be verifiable on the NIOSH Certified Equipment List (CEL). See the NIOSH 42 CFR Part 84 respirator certification guide for the full certification framework, N/R/P classification, and step-by-step CEL verification. Dust masks, surgical masks, and comfort face coverings are not NIOSH-certified respirators and do not satisfy this requirement.

Assigned Protection Factors and Maximum Use Concentration

The APF is the minimum workplace level of respiratory protection expected from a properly worn, fitted, and trained respirator class. The MUC is calculated as APF × applicable OEL — it is the highest airborne concentration at which a given respirator is permitted for use. Selecting a respirator with an MUC below the measured or estimated exposure concentration is a §1910.134(d)(3) violation regardless of the respirator's NIOSH approval class.

APF values apply only to properly fitted and worn respirators — a worker without a current fit test, without medical clearance, or who has not performed a user seal check does not receive the benefit of the stated APF. The employer cannot simply specify a full-face APR (APF 50) and assume the protection level is achieved without the surrounding program infrastructure. Browse the 3M full-face mask respirator lineup — APF 50 — for the equipment specification; the program infrastructure is what activates the APF claim.

Cartridge and filter selection

§1910.134(d)(1)(iii) requires that the respirator selected be appropriate for the chemical state and physical form of the contaminant. For particulate hazards, the filter efficiency class (N, R, or P at 95, 99, or 100%) must be matched to the oil aerosol content of the atmosphere — the NIOSH 42 CFR Part 84 N/R/P classification guide covers this in detail. For gas/vapor hazards, the cartridge sorbent must be appropriate for the contaminant: organic vapor (OV) cartridges like the 3M 6001 for solvent vapors; acid gas cartridges for HCl, SO₂, or HF; combination cartridges for mixed-hazard environments. When both particulate and vapor hazards are present — spray painting with solvent-based coatings, welding on coated steel, abrasive blasting — a combination OV/P100 or multi-gas/P100 cartridge is required. The 3M respirator cartridges and filters lineup covers the full spectrum from particulate-only P100s through combination multi-gas/P100 configurations.

Cartridge change-out schedule — §1910.134(d)(3)(iii)(B)

For atmosphere-purifying respirators with cartridges subject to end-of-service-life considerations (primarily OV and combination cartridges), §1910.134(d)(3)(iii)(B) requires a change-out schedule based on "objective information or data that will ensure that sorbent cartridges and canisters are changed before the end of their service life." This requirement is frequently cited because employers document a schedule ("change at end of shift") without documenting the objective basis for that interval. The acceptable basis for a change-out schedule is: manufacturer service-life data, OSHA CARB data, or a mathematical service-life calculation accounting for contaminant concentration, breathing rate, temperature, and humidity. See the ANSI/ISEA Z88.2 guide for the ESLI and calculation methodology that satisfies this requirement in detail.

Part 5 — Medical evaluation — §1910.134(e) and Appendix C

§1910.134(e) requires medical evaluation before a worker wears a required respirator for the first time. The evaluation must be conducted by a Physician or Licensed Health Care Professional (PLHCP) — defined in §1910.134(b) as an individual whose legally permitted scope of practice allows them to independently provide the health care services required by the standard. The employer is responsible for providing the medical evaluation at no cost to the employee and during normal working hours or at a convenient time.

The Appendix C questionnaire process

The medical evaluation begins with OSHA Appendix C — a mandatory written questionnaire that employees complete privately and submit directly to the PLHCP. The questionnaire covers cardiovascular and pulmonary health history, current symptoms, and relevant medication use. The employer does not see the questionnaire responses — only the PLHCP's written recommendation, which states whether the employee is cleared to wear the specified respirator type, cleared with restrictions, or not cleared.

When is re-evaluation required?

Medical evaluation is not automatically annual under 1910.134 — the initial evaluation is required before first use, and re-evaluation is triggered by: (1) an employee reporting signs or symptoms related to the ability to use a respirator; (2) a PLHCP, supervisor, or program administrator concluding a re-evaluation is needed; (3) information from the fit testing or program indicates a need; or (4) a change in workplace conditions that may substantially increase the physiological burden on the employee. Many substance-specific standards (1926.1153 silica, 1926.1101 asbestos, 1926.62 lead) overlay periodic medical surveillance requirements that effectively require annual re-evaluation on a separate statutory basis.

Part 6 — Fit testing — §1910.134(f) and Appendix A

§1910.134(f) requires fit testing for all tight-fitting respirators used in required programs. Fit testing must be performed before initial use and annually thereafter, and must be repeated when the employee reports, or the employer observes, changes in the employee's physical condition that could affect respirator fit. Fit testing must be conducted using an Appendix A-accepted protocol on the specific respirator model the employee will use — a fit test on one manufacturer's half-face respirator does not cover a different manufacturer's model, and a fit test on a medium-size facepiece does not cover a large.

Qualitative fit test (QLFT) protocols — Appendix A

OSHA Appendix A accepts four qualitative fit test protocols. All four test whether the subject can detect a challenge agent introduced into the test enclosure around their facepiece:

• Isoamyl acetate (banana oil): Olfactory detection. Cannot be used for workers who cannot detect the odor of isoamyl acetate at a concentration below its TLV/OEL.
• Saccharin solution aerosol: Sweet taste detection. Worker must be able to taste saccharin to use this protocol.
• Bitrex (denatonium benzoate) solution aerosol: Bitter taste detection. The most widely used QLFT protocol; suitable for most workers.
• Irritant smoke (stannic chloride): Detects visible leakage; used as a screening protocol only — not suitable as the sole QLFT for all facepiece sizes.

Qualitative protocols are limited to respirators with an APF of 10 or below — they cannot be used to fit-test full-face APRs (APF 50) or higher-APF equipment.

Quantitative fit test (QNFT) protocols — Appendix A

Quantitative protocols measure the actual particle count inside vs. outside the facepiece and calculate a fit factor. They are required for full-face APRs and are used when a higher confidence in fit factor is needed. Appendix A accepts three QNFT protocols: generated aerosol (using a PortaCount or similar instrument), condensation nuclei counter (CNC), and controlled negative pressure (CNP). The minimum acceptable fit factor under Appendix A is 100 for half-face respirators and 500 for full-face respirators. Fit factor is not the same as APF — a measured fit factor of 500 does not give an APF of 500; the APF is set by respirator class, not by individual fit test result.

Part 7 — Respirator use — §1910.134(g)

User seal checks — §1910.134(g)(1)

§1910.134(g)(1)(ii) requires that employees perform a user seal check each time they put on a tight-fitting respirator. Two seal check methods are described in mandatory Appendix B-1: the positive pressure check (exhale gently; if facepiece bulges slightly and no outward leakage is detected, fit is adequate) and the negative pressure check (inhale sharply; if facepiece collapses slightly and no inward leakage is detected, fit is adequate). User seal checks are not the same as fit testing — they are a daily pre-use verification that the respirator is properly donned. They must be performed every time a respirator is donned, not just at the start of a shift.

Facial hair — §1910.134(g)(1)(i)

§1910.134(g)(1)(i) prohibits use of a tight-fitting facepiece by any employee who has facial hair that comes between the sealing surface and the face, or that interferes with valve function. This prohibition applies to stubble, beard, sideburns that contact the seal, and goatees. There is no "de minimis" stubble allowance in the standard — any stubble that contacts the sealing surface is non-compliant. Workers with facial hair who require respirator protection must use a loose-fitting facepiece (PAPR with hood or helmet) that does not require a facial seal.

IDLH atmospheres — §1910.134(g)(2)

§1910.134(g)(2) requires that in IDLH (Immediately Dangerous to Life or Health) atmospheres, the employer provide a pressure-demand SCBA or a combination pressure-demand supplied-air respirator with auxiliary SCBA. At least one standby employee must be located outside the IDLH atmosphere with two-way communication to the interior, and rescue equipment must be available. No air-purifying respirator — regardless of filter class or APF — may be used in IDLH conditions.

Part 8 — Maintenance, care, recordkeeping, and common citations — §§1910.134(h)–(m)

Maintenance and care — §1910.134(h)

Reusable respirators must be cleaned and disinfected at a frequency that prevents worker health impairment. Appendix B-2 provides cleaning procedures. Respirators must be inspected before each use and during cleaning — checking straps, facepiece condition, valve condition, and connection points. Damaged respirators must be removed from service and replaced or repaired per manufacturer specifications. Storage must protect respirators from dust, sunlight, extreme temperatures, excessive moisture, and chemicals — keeping a full-face APR from the 3M 7800 Series in a tool locker exposed to solvents, for example, violates this requirement.

Recordkeeping — §1910.134(m)

Three categories of records must be maintained:

• Fit test records: Retain until the next fit test is conducted. Record must include the worker's name, test date, protocol used, respirator model and size, TC approval number, and pass/fail result.
• Medical evaluation records: Maintain per 29 CFR 1910.1020 (access to employee exposure and medical records). This regulation requires 30-year retention for occupational exposure records; for the medical questionnaire and clearance letter, retain for the duration of employment plus 30 years.
• Written respiratory protection program: Maintain and make available to all affected employees and OSHA representatives. No minimum retention period is specified for superseded versions, but best practice is to retain historical WRPPs for 3–5 years for audit trail purposes.

Most common 1910.134 citation patterns

OSHA enforcement data consistently identifies five recurring failure modes across industries:

• No written respiratory protection program — the most frequent citation; the absence of a WRPP is per se non-compliant the moment a required respirator program exists, regardless of whether workers were actually harmed.
• Missing or undocumented medical evaluations — workers wearing required respirators without a PLHCP clearance on file, or clearances that predate the 1998 requirement and were never updated.
• Missing or expired fit test records — annual requirement; records lost when workers change employers; common in industries with high workforce turnover.
• No documented cartridge change-out schedule or schedule without objective basis — a common citation for OV and combination cartridge programs where the written program simply says "replace after use" without specifying a calculated or manufacturer-data-based interval.
• Facial hair at sealing surface — consistently cited; enforcement does not require air monitoring — a compliance officer who observes stubble contacting a sealing surface can cite immediately.

Part 9 — Worked example: implementing a 1910.134-compliant program for a manufacturing maintenance operation

The following six steps walk through building a 1910.134-compliant respiratory protection program for a manufacturing plant maintenance team that performs two types of respiratory-hazard work: (1) solvent degreasing using a parts washer with a petroleum-based solvent (organic vapor hazard), and (2) angle grinding and cutting on steel and cast iron components (iron oxide fume and metal dust particulate hazard). The respirators specified in this example are the 3M 6001 OV cartridge and the 3M 2091 P100 filter, fitted to half-face respirators from the 3M 6000 Series.

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1. Determine whether respirator use is required under §1910.134(a). For each task, confirm whether engineering controls can reduce exposure below the applicable PEL. For the solvent degreasing operation: review the product SDS for the petroleum solvent — identify the primary solvent component (e.g., naphtha, mineral spirits) and its OSHA PEL. If general ventilation in the degreasing area is inadequate to keep the 8-hour TWA below the PEL, respiratory protection is required. For the grinding operation: iron oxide fume PEL is 10 mg/m³ as an 8-hour TWA; personal air monitoring during grinding operations will determine whether ventilation keeps fume levels below this threshold. If required, the program must satisfy all 1910.134 requirements. If exposures are below the PEL with controls and the employer elects to allow voluntary half-face APR use, the full written program, medical evaluations, and fit testing still apply per §1910.134(c)(2).
2. Select NIOSH-approved respirators with adequate APF for each task. For the solvent degreasing task, the primary hazard is organic vapor — select a half-face APR with a 3M 6001 OV cartridge (APF=10, MUC = 10× the solvent PEL). If measured concentrations could approach or exceed 10× the PEL, step up to a full-face APR from the 3M full-face mask respirator lineup (APF=50, MUC = 50× PEL). For the grinding task, the primary hazard is iron oxide fume and metal dust — select a half-face APR with the 3M 2091 P100 filter (APF=10). If workers may perform both tasks in sequence without fully doffing the respirator, specify the 3M 60921 OV/P100 combination cartridge to cover both hazard classes in a single equipment configuration. Verify the TC approval number for each selected cartridge on the NIOSH CEL and record it in the written program. For detailed guidance on reading and verifying NIOSH approval labels, see the how to read a NIOSH approval label guide.
3. Draft and implement the written respiratory protection program per §1910.134(c). Create a WRPP document with a section for each of the eight required elements in §1910.134(c)(1). For each task entry in the written program, record: the task name, the hazard identified, the measured or estimated exposure level, the applicable PEL, the required APF, the selected NIOSH-approved respirator model and TC approval number, the cartridge change-out schedule with its objective basis (see Step 4), and the applicable OSHA standards. Designate a program administrator and include their name and qualifications in the program. The WRPP is a living document — update it whenever a new chemical is introduced, a task changes, or a new respirator model is selected. Make the completed WRPP accessible to all maintenance team members who are covered by the program.
4. Administer medical evaluations per §1910.134(e) and Appendix C. Before any maintenance worker wears a required respirator for the first time, arrange for each worker to complete the Appendix C medical questionnaire. Route the completed questionnaire directly to the PLHCP — do not review its contents as the employer. Retain the PLHCP's written clearance recommendation on file per §1910.134(m)(4)(ii). For workers who are cleared with restrictions (e.g., cleared only for half-face APR, not full-face), ensure the written program reflects those restrictions and the selected equipment matches. For workers with a history of significant cardiovascular or pulmonary conditions, the PLHCP may request a follow-up exam before issuing clearance — the employer must provide this at no cost.
5. Conduct and document fit testing on the specific respirator model each worker will use. Schedule fit testing for all workers before their first use and annually thereafter. Select a protocol from Appendix A appropriate for the respirator type: qualitative (Bitrex or saccharin) is appropriate for the half-face APR (APF=10); quantitative testing is required if full-face APRs are in the program. Conduct the test with the same respirator model, size, and cartridge configuration the worker will actually use — a test on a size Medium 3M 6500 half-face does not cover a 3M 6800 full-face, and vice versa. Record the fit test results per §1910.134(m)(1): worker name, test date, protocol, respirator make/model/size/TC number, and pass/fail. Retain until the next fit test. If a worker fails all available half-face APR sizes and models, arrange a fit test on a full-face APR or a PAPR hood — do not assign the worker to a required respirator task until an adequate fit is documented. For product-level guidance on compatibility, see the 3M 2091 P100 respirator filter review.
6. Train workers, implement user seal checks, and establish the cartridge change-out schedule. Deliver initial training per §1910.134(k) — covering why the respirator is necessary, its capabilities and limitations, proper donning/doffing, the Appendix B-1 user seal check procedure, maintenance and storage, and medical symptoms that may indicate the respirator is impairing the worker. Training must be in a language and vocabulary the worker understands. For the cartridge change-out schedule: for the 3M 6001 OV cartridge on the solvent degreasing task, use the 3M Service Life Software with the measured solvent concentration, expected work rate (moderate = approximately 25 L/min breathing rate), temperature, and relative humidity to calculate the estimated service life. Enter the calculated hours (or the manufacturer's worst-case interval if calculation data is unavailable) as the maximum service interval in the written program. For the 3M 2091 P100 filter on the grinding task, change-out is based on breathing resistance — replace when resistance is noticeably increased or when the filter is physically damaged. Document both change-out schedules with their objective basis in the written program per §1910.134(d)(3)(iii)(B). Annual program evaluation per §1910.134(l) should include a review of whether change-out intervals are being followed and whether any workers have reported cartridge odor breakthrough.

Frequently asked questions about OSHA 29 CFR 1910.134

What is OSHA 29 CFR 1910.134?

OSHA 29 CFR 1910.134 is the general industry respiratory protection standard. Located in OSHA's Part 1910 Subpart I (Personal Protective Equipment), it requires employers to establish written respiratory protection programs covering NIOSH-approved respirator selection, medical evaluation, fit testing, user seal checks, training, and recordkeeping whenever respirators are used — whether required by a hazard assessment or voluntarily worn. The standard was substantially revised in 1998 and further amended in 2006 to add the mandatory APF table.

When is a written respiratory protection program required under 1910.134?

A written respiratory protection program is required under §1910.134(c)(1) whenever respirator use is required because engineering controls cannot reduce exposures below applicable PELs, and whenever any respirator other than a filtering facepiece is used voluntarily. Voluntary use of half-face APRs, full-face APRs, or PAPRs requires a full written program, medical evaluations, and fit testing. Voluntary use of filtering facepieces (N95 disposables) requires only providing OSHA Appendix D information to the user — no written program, medical evaluation, or fit testing is required for this specific scenario.

What respirators does 1910.134 require to be NIOSH-approved?

§1910.134(d)(1)(ii) requires that all respirators used in required programs be NIOSH-certified under 42 CFR Part 84. Every NIOSH-certified respirator carries a TC approval number (format: TC-84A-XXXX) verifiable on the NIOSH Certified Equipment List (CEL). Respirators without a valid, current TC approval number are not compliant with 1910.134 regardless of their filtration claims. See the NIOSH 42 CFR Part 84 respirator certification guide for full approval verification steps.

What is an Assigned Protection Factor under 1910.134?

The Assigned Protection Factor (APF) — codified in 1910.134(d)(3)(i)(A) by the 2006 Final Rule — is the workplace level of respiratory protection a respirator or class of respirators is expected to provide when worn by a properly fitted, trained employee. Multiplied by the applicable OEL, the APF yields the Maximum Use Concentration (MUC): the highest airborne concentration at which a given respirator is permitted for use. A half-face APR has an APF of 10 (MUC = 10× PEL); a full-face APR has an APF of 50 (MUC = 50× PEL).

What does 1910.134 require for medical evaluations?

§1910.134(e) requires a PLHCP-administered medical evaluation before initial required respirator use. The process begins with the mandatory Appendix C questionnaire, completed privately by the employee and submitted directly to the PLHCP. The employer receives only the PLHCP's written recommendation — cleared, cleared with restrictions, or not cleared. Re-evaluation is triggered by employee symptoms, PLHCP recommendation, fit testing observations, or changed work conditions. Medical evaluation is not automatically annual under 1910.134, but substance-specific standards may impose periodic surveillance on top of this baseline.

How often is fit testing required under 1910.134?

§1910.134(f) requires fit testing before initial use of a tight-fitting facepiece in a required program and annually thereafter. Fit testing must be repeated if the employee's physical condition changes in a way that could affect facepiece fit — significant weight change, dental work, facial surgery, or reported discomfort. Fit test records must be retained until the next fit test is conducted. The test must be performed on the specific model the worker will use — tests are not transferable between models or manufacturers.

What fit test protocols does OSHA 1910.134 accept?

OSHA Appendix A (mandatory) lists four accepted qualitative protocols (isoamyl acetate, saccharin solution, Bitrex solution, irritant smoke) and three accepted quantitative protocols (generated aerosol, condensation nuclei counter, controlled negative pressure). Qualitative protocols are limited to respirators with an APF of 10 or below — they cannot be used to fit-test full-face APRs. Quantitative protocols may be used for any tight-fitting respirator; the minimum acceptable fit factor is 100 for half-face and 500 for full-face respirators.

What is the Maximum Use Concentration under 1910.134?

The MUC is calculated as APF × applicable OEL. It is the highest airborne concentration at which a given respirator type may be used. Example: for silica dust (OSHA PEL 50 µg/m³), a half-face APR (APF=10) has a MUC of 500 µg/m³; a full-face APR (APF=50) has a MUC of 2,500 µg/m³. If measured or estimated exposure exceeds the respirator's MUC, a higher-APF respirator is required. Employers cannot use a respirator above its MUC regardless of filter efficiency — an N100 on a half-face respirator still has an APF of 10 and a MUC of 10× PEL because the limiting factor is facepiece seal, not filter efficiency.

Does 1910.134 apply to construction?

Yes, through OSHA 29 CFR 1926.103. The construction respiratory protection standard requires compliance with all elements of 1910.134. Construction employers are not exempt from any 1910.134 requirement by virtue of operating under 1926.103. Additionally, substance-specific construction standards (1926.1153 for silica, 1926.1101 for asbestos, 1926.62 for lead) add requirements on top of the 1926.103/1910.134 baseline. See the OSHA 29 CFR 1926.103 construction respiratory protection guide for full construction coverage.

What does 1910.134 require for voluntary respirator use?

§1910.134(c)(2) creates two tiers of voluntary use obligation. For voluntary use of filtering facepieces (N95 disposables), the employer must only provide Appendix D information — no written program, medical evaluation, or fit testing required. For voluntary use of any other respirator (half-face APR, full-face APR, PAPR), the employer must implement a written program, conduct medical evaluations, and ensure fit testing for tight-fitting facepieces — the same administrative infrastructure as required use. Allowing voluntary use of half-face or full-face APRs without this infrastructure is a 1910.134 violation.

What are the 1910.134 user seal check requirements?

§1910.134(g)(1)(ii) requires employees to perform a user seal check each time they don a tight-fitting respirator. Appendix B-1 (mandatory) describes the positive-pressure check (exhale gently; check for facepiece bulge without outward leakage) and negative-pressure check (inhale sharply; check for facepiece collapse without inward leakage). Workers must be trained in the appropriate seal check for their specific respirator — some manufacturers specify a preferred method that varies from the generic Appendix B-1 procedure, and the manufacturer method is acceptable if it provides equivalent protection.

What cartridge change-out documentation does 1910.134 require?

§1910.134(d)(3)(iii)(B) requires a written change-out schedule for sorbent cartridges and canisters that is based on objective information or data. The schedule must be in the written program and must specify the basis for the interval — whether manufacturer service-life data, OSHA CARB data, or a mathematical service-life calculation. A schedule that states "replace after each shift" without documenting why that interval is protective for the specific solvent concentration and work conditions does not meet this requirement. This is one of the most frequently cited elements in 1910.134 enforcement.

What are 1910.134 IDLH requirements?

§1910.134(g)(2) requires that in IDLH atmospheres, the employer provide a pressure-demand SCBA or a combination pressure-demand supplied-air respirator with auxiliary SCBA. At least one standby employee must be located outside the IDLH atmosphere with two-way communication to the interior. Rescue procedures and equipment must be available. Air-purifying respirators — regardless of filter efficiency or APF — are prohibited in IDLH atmospheres. IDLH is defined in §1910.134(b) as any atmosphere that poses an immediate threat to life, would cause irreversible adverse health effects, or would impair an individual's ability to escape.

What training does 1910.134 require?

§1910.134(k) requires initial training before first use and annual retraining. Required content includes: why the respirator is necessary and how improper fit, use, or maintenance can compromise protection; the program's limitations and capabilities; how to use the respirator in emergency situations; how to inspect, don, doff, use, and check seals; maintenance and storage procedures; and medical signs and symptoms that may limit effective use. Training must be comprehensible to all workers — language and literacy barriers do not exempt an employer from the requirement, they just mean the employer must provide language-accessible training.

What records must be kept under 1910.134?

§1910.134(m) requires retention of: (1) fit test records — until the next fit test; (2) medical evaluation records — per 29 CFR 1910.1020's 30-year retention requirement; (3) the written respiratory protection program — retained and available to workers on request. Employers must provide access to these records to affected employees, employee representatives, and OSHA. Records must be provided within 15 working days of an employee's or OSHA's written request.

What is 1910.134 Appendix A?

Appendix A (mandatory) contains the fit testing procedures accepted by OSHA. It lists four qualitative protocols (isoamyl acetate, saccharin solution aerosol, Bitrex solution aerosol, irritant smoke) and three quantitative protocols (generated aerosol, condensation nuclei counter, controlled negative pressure). Each protocol includes detailed step-by-step administration instructions and pass/fail criteria. Fit test administrators must follow these protocols as written — modified or abbreviated protocols do not satisfy 1910.134(f).

What is 1910.134 Appendix D?

Appendix D (mandatory) is titled "Information for Employees Using Respirators When Not Required Under the Standard." It must be provided to any employee who voluntarily wears a filtering facepiece respirator (N95 or similar) when no respirator use is required. The Appendix D information covers the respirator's limitations, the importance of using only NIOSH-approved devices, and the need for proper fit and condition. It does not require the employer to implement a written program or conduct fit testing — it is an information provision obligation only, specific to the filtering facepiece voluntary-use scenario.

What are the most common 1910.134 citation types?

OSHA enforcement data consistently identifies five recurring failures: (1) no written respiratory protection program when one is required; (2) missing or undocumented medical evaluations; (3) missing or expired annual fit test records; (4) no documented cartridge change-out schedule, or a schedule without an objective data basis; and (5) facial hair at the sealing surface of a tight-fitting facepiece. The first three are administrative deficiencies that OSHA can cite without conducting air monitoring. The fifth can be cited by direct observation alone. All five are preventable through routine administrative maintenance of the written program and records.

Further reading on this site

• NIOSH 42 CFR Part 84 respirator certification guide — the device certification standard that underpins 1910.134's NIOSH-approval requirement; N/R/P classification, TC approval numbers, and CEL verification.
• OSHA 29 CFR 1926.103 construction respiratory protection guide — how 1926.103 incorporates 1910.134 for construction, with APF table application for silica and asbestos operations.
• ANSI/ISEA Z88.2 respiratory protection program standard guide — the professional consensus standard that provides best-practice program design guidance above the 1910.134 legal minimum; cartridge change-out calculation, administrator qualifications, program evaluation.
• How to read a NIOSH approval label — field guide to verifying that a respirator satisfies 1910.134's NIOSH-approval requirement.
• Best 3M full-face respirator buyer's guide — comparison of 3M 6000, 7800, and Ultimate FX series for the APF-50 full-face scenarios required when exposure exceeds 10× the applicable PEL.
• 3M respirator cartridges and filters — OV, P100, OV/P100, acid gas/P100, and multi-gas cartridges for the 1910.134 selection scenarios covered in this guide.
• 3M 2091 P100 respirator filter review — compatibility notes and performance data for the standard P100 particulate filter used in 1910.134-compliant programs across manufacturing and construction.

Related guides and reference pages

• Respiratory protection complete buyer's guide — comprehensive pillar covering all aspects of OSHA 1910.134 compliance: APF table, MUC calculations, written program requirements, fit testing, and respirator selection by hazard class.
• NIOSH 42 CFR Part 84 respirator certification guide — 1910.134(d)(1)(ii) requires NIOSH-certified respirators only; covers TC approval numbers, N/R/P filter classes, and CEL verification before specifying any respirator.
• OSHA 29 CFR 1926.103 construction respiratory protection guide — construction standard that incorporates 1910.134 with additional site-specific requirements; competent person designation, multi-employer site obligations, and silica interaction.
• ANSI/ISEA Z88.2 respiratory protection program standard guide — voluntary standard that expands on 1910.134's written program requirements; OEL hierarchy, selection methodology, and program administration detail beyond the regulatory minimums.
• OSHA 29 CFR 1926.1153 construction silica standard guide — silica substance-specific standard built on the 1910.134 framework; PEL 50 µg/m³, action level 25 µg/m³, P100 requirements for high-exposure construction tasks.
• Respirator fit testing guide — deep dive into 1910.134(f) fit testing requirements: QLFT vs QNFT protocols, pass/fail thresholds (FF ≥100 half-face / ≥500 full-face), and documentation obligations.
• Respirator cartridge change-out schedule guide — 1910.134(d)(3)(iii) mandates ESLI or a calculated change-out schedule before each shift; covers both methods including 3M Service Life Software input procedure for common solvents.
• ACGIH TLVs vs OSHA PELs respirator selection guide — 1910.134 requires OEL-based selection; using ACGIH TLV as governing OEL (per ANSI Z88.2) can require a higher APF class than PEL-only selection, and changes WRPP documentation requirements.
• 3M full-face mask respirator collection — APF 50 NIOSH-approved respirators for exposures where half-face MUC is insufficient; 3M 6000, 7800, and Ultimate FX series.
• 3M respirator cartridges and filters — OV, acid gas, P100, OV/P100 combination, and multi-gas cartridges for 1910.134-compliant written programs.