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Before a lab worker ever puts on a respirator — N95, elastomeric half-mask, or full-face — someone has to determine whether their body can actually handle wearing one. That determination is the medical evaluation required by 29 CFR §1910.134(e), and its centerpiece is a specific document: the mandatory questionnaire in Appendix C of the standard. This guide covers what that questionnaire actually asks, who has to complete it, what happens after a lab worker submits it, and where medical clearance sits relative to fit testing in the sequence of getting someone into a respirator. For the full nine-element written program a respirator-issuing lab needs, see Respiratory Protection Program for Laboratories — this page goes deep on one element of that program.
Who needs the Appendix C questionnaire: mandatory use vs. voluntary use
§1910.134(e)(1) requires the employer to “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.” That requirement is triggered by required (mandatory) respirator use without exception. It is easy to assume voluntary use sidesteps medical evaluation entirely — it doesn’t, except for one specific case.
§1910.134(c)(2)(ii) exempts only voluntary use of filtering facepieces (disposable dust-mask-style respirators, no cartridges) from the full written program, including the medical evaluation. That employee instead just receives Appendix D, an information sheet, and nothing more. The exemption does not extend to voluntary use of any other respirator type — an elastomeric half-mask, a full-face respirator, or a PAPR worn voluntarily still requires the Appendix C medical evaluation under §1910.134(c)(2)(i). In a lab, this distinction matters most for the researcher who wants to wear a reusable elastomeric respirator instead of disposable N95s for comfort or fit reasons on a task that doesn’t strictly require one: that preference still routes through medical clearance, because the exemption is written narrowly around filtering facepieces specifically, not around “voluntary” as a general category.
What the questionnaire actually asks
Appendix C’s questionnaire is split into two parts. Part A is the piece every employee undergoing evaluation completes: general information (job title, respirator type and expected duration/frequency of wear), followed by a screening section covering cardiovascular history (chest pain, heart conditions, high blood pressure), pulmonary history (asthma, chronic bronchitis, emphysema, shortness of breath), and other conditions relevant to breathing resistance and psychological tolerance of a sealed facepiece — claustrophobia among them. A second Part A section applies specifically to employees who will use a negative-pressure, tight-fitting respirator (which covers most lab respirator use, since PAPRs and supplied-air setups are the exception in bench work): additional questions on more serious cardiopulmonary history go here, because a negative-pressure device demands more respiratory effort from the wearer than a powered, loose-fitting alternative.
Part B is a supplemental history section the PLHCP can request if Part A responses, the employee’s job duties, or the specific respirator type warrant a deeper look — it is not completed by every employee automatically.
The PLHCP reviews the completed questionnaire and, based on the responses alone, either clears the employee or calls for a follow-up physical examination before making a determination. Most employees with an unremarkable Part A questionnaire are cleared on the questionnaire alone; a follow-up exam is the exception triggered by a specific flagged response or the PLHCP’s own judgment, not a routine second step every wearer goes through.
Confidentiality: what the questionnaire covers, and what the employer actually receives
§1910.134(e)(2) requires the questionnaire and any exam to be “administered confidentially during the employee’s normal working hours or at a time and place convenient to the employee,” and the employee’s actual medical responses are not disclosed to the employer. What the employer (or, in a lab, whoever administers the respirator program — typically EHS, not the PI) receives back is a written recommendation from the PLHCP, limited to four things: whether the employee is medically able to use the respirator, any use limitations tied to a medical condition (e.g., a lower-exertion respirator type, or a shorter wear-time), whether follow-up evaluation is needed, and confirmation the employee received a copy of the PLHCP’s written opinion. The underlying clinical detail — what specific condition, if any, drove a limitation — stays with the PLHCP and the employee, not the lab’s safety file. This is a meaningful distinction to communicate to lab staff who may otherwise be reluctant to answer the questionnaire honestly out of concern that a supervisor will see specific health details; they won’t.
Fit testing comes after clearance, not before
The sequencing in §1910.134(e)(1) is explicit: medical evaluation has to happen before the employee is fit tested or assigned a respirator, not after or in parallel. A lab that schedules a batch fit-testing session and pulls in whichever staff show up, checking medical-clearance paperwork afterward as a formality, has the sequence backward and is out of compliance the moment an uncleared employee is fit tested — the standard doesn’t treat fit testing as evidence of fitness to wear a respirator, and a passed fit test doesn’t retroactively substitute for a missing medical clearance. In practice, this means a respirator program administrator needs the PLHCP’s written recommendation on file before booking anyone into a fit-test session, not the other way around. For the mechanics of the fit test itself — qualitative vs. quantitative methods, the annual requirement, why facial hair disqualifies a test — see Respirator Fit Testing: Qualitative vs. Quantitative, and What the Annual Requirement Covers.
When the PLHCP calls for re-evaluation
Initial clearance is not a one-time event good for the life of the job. §1910.134(e)(7) requires the employer to provide an additional medical evaluation if any of four things happen:
- The employee reports medical signs or symptoms related to their ability to use a respirator.
- A PLHCP, supervisor, or the respirator program administrator informs the employer the employee needs to be reevaluated.
- Information from the respiratory protection program itself — including observations made during fit testing — indicates a need for reevaluation. A lab worker who struggles, reports dizziness, or shows visible distress during an annual fit test is a trigger event on its own, independent of anything the worker proactively reports.
- A change occurs in workplace conditions (heavier protective clothing, higher physical exertion, elevated temperature) that could substantially increase the physiological burden the respirator places on the employee.
None of these are tied to a fixed calendar the way fit testing’s annual requirement is — re-evaluation is event-triggered, and a lab that only revisits medical clearance when fit-testing paperwork happens to be due is missing the standard’s actual triggers.
What if the PLHCP says no
A PLHCP can clear an employee with limitations (a lighter respirator class, shorter continuous wear time) or determine they cannot safely wear a respirator of the type in question at all. That is not a dead end for the underlying task — it pushes the lab back to the hierarchy of controls: better engineering controls (a properly functioning fume hood, local exhaust ventilation) or administrative controls (task reassignment, reduced exposure duration) that reduce or eliminate the need for that employee specifically to wear that respirator. A PAPR with a loose-fitting hood is also worth considering where a tight-fitting negative-pressure respirator is medically inappropriate for an employee but a powered, loose-fitting alternative places substantially less physiological burden on them — see the PAPR discussion in the full program guide for when that swap makes sense.
FAQ
Does every lab respirator wearer need to complete Appendix C?
Everyone under required (mandatory) use, yes. Under voluntary use, only filtering-facepiece (dust mask) wearers are exempt; voluntary use of any other respirator type still requires the Appendix C evaluation.
Who sees the answers on the medical questionnaire?
The PLHCP administering it. The employer receives only a written recommendation limited to fitness, use limitations, and whether follow-up evaluation is needed — not the underlying medical responses.
Can an employee be fit tested before their medical clearance comes back?
No. §1910.134(e)(1) requires medical evaluation before fit testing or respirator use, not concurrently or afterward.
Does a lab worker need to redo the questionnaire every year, like fit testing?
No. Medical re-evaluation is triggered by specific events under §1910.134(e)(7) — reported symptoms, a PLHCP/supervisor/administrator recommendation, fit-test observations, or a substantial change in physiological burden — not by a fixed annual schedule the way fit testing is.
What happens if the PLHCP won’t clear an employee for the respirator their task calls for?
The lab falls back to the hierarchy of controls: stronger engineering or administrative controls to reduce the need for that respirator, or a different respirator class (such as a PAPR) that places less physiological burden on that employee.
