Wearing a respirator in the workplace introduces a physical strain that requires a medical assessment for safety. A Pulmonary Function Test (PFT) uses spirometry to measure how well the lungs move air, providing data on respiratory capacity. Because wearing a respirator increases the effort required to breathe, a medical evaluation is mandated to ensure the user is physically capable of handling this added stress. The PFT is one tool used in this process, but it is not the universal starting point for every employee needing respiratory protection.
The Mandatory Medical Evaluation for Respirator Users
Before an employee can be fit-tested or assigned to work while wearing a respirator, a medical evaluation must be completed by a physician or other licensed healthcare professional (PLHCP). This requirement is established under OSHA standard 29 CFR 1910.134. This initial screening determines the employee’s ability to tolerate the physiological burden of respirator use, which affects both the cardiovascular and respiratory systems.
The foundational step is the completion of a mandatory medical questionnaire, often referred to as Appendix C. This confidential questionnaire screens for pre-existing medical conditions that could be aggravated by wearing a respirator, such as heart disease, asthma, or COPD. The PLHCP reviews the responses to identify potential contraindications or symptoms, like unexplained shortness of breath or chest pain.
This medical questionnaire is the primary screening tool for all respirator users. The PLHCP’s review determines if the employee can be immediately cleared for use. For most workers using simple air-purifying respirators, the questionnaire alone satisfies the regulatory requirement. Therefore, the PFT is generally considered a secondary, follow-up step rather than a required initial test.
When a Pulmonary Function Test Becomes Necessary
A Pulmonary Function Test (PFT) is not universally required by OSHA’s respiratory protection standard, but it becomes a necessary component of the medical evaluation under specific conditions. The PFT is primarily triggered when the PLHCP identifies potential concerns based on the initial medical questionnaire. A positive response to questions concerning heart or lung conditions, or the reporting of symptoms like wheezing or significant shortness of breath, usually necessitates further objective testing.
The PFT, most commonly performed as spirometry, measures various aspects of lung mechanics, including capacity and airflow. This test evaluates the lungs’ ability to move air in and out, which is directly relevant to safe respirator use because the mask creates breathing resistance. The most common measurements are Forced Vital Capacity (FVC), the total amount of air exhaled after a deep breath, and Forced Expiratory Volume in one second (FEV1), the amount exhaled in the first second. These values are compared to predicted norms based on the employee’s demographics to determine lung function status.
A PFT is also frequently required for employees who will use respirators that place a higher demand on the respiratory system. This includes self-contained breathing apparatus (SCBA) or other heavy pressure-demand systems. The physical exertion associated with carrying and using an SCBA unit significantly increases the physiological burden, necessitating a more thorough assessment of lung capacity. Additionally, OSHA mandates PFTs as part of medical surveillance for exposure to specific substances:
- Asbestos
- Formaldehyde
- Cotton dust
- Silica
The employer may also choose to require a PFT as a standard practice for all respirator users, even if the questionnaire is negative, as a more conservative screening measure. Some studies suggest the questionnaire alone may fail to identify workers who have inadequate lung function to safely wear a respirator. While the PFT is not a blanket mandate, it is a common requirement for employees with risk factors or those using demanding respiratory equipment.
Understanding the Impact of PFT Results on Respirator Use
The PFT results provide the PLHCP with objective data necessary to finalize the employee’s fitness determination for respirator use. Low values in key metrics like FEV1 or FVC can indicate an obstructive or restrictive lung disorder, suggesting the employee may struggle with the added resistance of a respirator. For example, a low FEV1/FVC ratio often indicates obstructive conditions like COPD, which makes exhalation difficult. The PLHCP considers these values alongside the job’s physical demands and the specific type of respirator being used.
The medical determination based on the PFT results leads to one of three outcomes regarding the employee’s clearance. Full clearance is granted when lung function is within acceptable parameters, indicating the worker can safely handle the physiological stress of the respirator. If the results show a measurable reduction in function, the PLHCP might grant clearance with limitations. These limitations could include allowing the employee to use only certain types of respirators, such as loose-fitting powered air-purifying respirators (PAPR), or imposing time limits on how long the respirator can be worn per shift.
If the PFT results show severely compromised lung function, the PLHCP may deny clearance for respirator use altogether. This determination is made purely for the safety of the employee, as wearing the device could pose a significant health risk, particularly under emergency conditions or high physical exertion. The PLHCP’s final recommendation focuses on ensuring that the employee’s respiratory health is not jeopardized by the job requirements.