By Marilyn A. Bishop MD, MPH, FABPM, MRO, AME, Ballad Health
The Occupational Safety and Health Administration (OSHA) estimates that around 5 million workers, representing about 20% of all businesses, use respirators as a crucial tool for worker protection when sufficient environmental controls are lacking. Respirators are employed to reduce workers’ exposure to airborne contaminants and provide protection during accidental releases or when entering hazardous areas. OSHA’s respiratory protection standard (29 CFR 1910.134) was first established in 1971, requiring employers to establish and maintain a respiratory protection program.
A crucial aspect of this standard is the requirement for a medical evaluation before respirator use. A qualified physician or licensed healthcare professional conducts this evaluation, determining the content and periodicity of reevaluations based on an individual’s health status. OSHA mandates a questionnaire as a screening tool to identify workers who may need further medical evaluation before respirator use, with a more comprehensive assessment required if “red flags” are identified.
Medical examiners responsible for these evaluations must understand the characteristics and physical requirements of various respiratory protection devices. Employers must provide NIOSH-certified respirators to their employees. The most commonly used respirator is the “air-purifying” negative pressure protective device, typically employing filters or cartridges to remove particulates or vapors. NIOSH classifies filtering respirators into N, R, and P categories with efficiency levels of 95, 99, and 99.97%. The examiner should be aware of facial or dental deformities, including facial hair, that may interfere with a proper seal, even though they are not responsible for the Fit Test required by OSHA.
Examiners may recommend a respirator that does not require a seal for employees with certain characteristics that prevent a proper seal. Air-purifying respirators vary in size and increase breathing resistance, and the examiner should consider the nature of the work being done while wearing the respirator. Pulmonary function testing may be required to assist in the medical qualification for respirator use and to determine any restrictions. While the increased work of breathing minimally contributes to the cardiac workload, changes in blood pressure, heart rate, and respiratory rate can occur in healthy individuals wearing respirators during heavy work after 5 minutes.
Powered air-purifying respirators (PAPRs) utilize a fan to force ambient air through a purification medium to the respiratory inlet covering, relieving the user of the effort required to inhale. PAPRs offer an increased protection factor beyond air-purifying devices and are generally considered more comfortable by most workers. These respirators do not need to fit tightly against the face, provide some cooling, and require less ventilatory effort. There is little to no intolerance or contraindication to this type of respirator.
Atmosphere-supplying respirators provide the highest level of protection by supplying breathing air independently of the ambient work environment. This can be delivered through a hose (supplied air respirator) or a self-contained breathing apparatus (SCBA). Supplied air respirators tether the worker to a hose, presenting a trip hazard, but there is little to no intolerance to this type of respirator. SCBAs, however, can weigh up to 40 pounds, are carried by the worker, and impose significant aerobic and musculoskeletal demands. When using an SCBA, additional protective equipment is often worn, increasing the worker’s heart rate and oxygen consumption. Environmental conditions, such as high temperatures or humidity, can further amplify these demands.
When an examiner is considering qualifying a worker for SCBA use, a thorough and comprehensive evaluation is recommended. This includes assessing the worker’s cardiac stability, and blood pressure control, and ensuring no increased risk for sudden loss of consciousness in a hazardous environment. Musculoskeletal factors that could impair the safety of the worker must also be considered before providing medical clearance for SCBA use.
The quality of the respirator’s medical evaluation depends on the examiner’s understanding of the specific demands placed on an individual by different respirators and the conditions under which they will be used. Developing strong relationships with employer clients and understanding the full scope of respiratory protection use in their environment contributes to both the quality and value of the examiner’s respiratory evaluations.
