If you have such a condition, a physician must examine you to determine if you are physically able to perform assigned work using respiratory equipment. The physician should determine what health and physical conditions are pertinent. Your employer must follow the physician's written recommendation concerning your capability to wear respiratory equipment. Your employer must keep written evidence on file that you were informed. Before an employee is required to perform any work that requires respiratory protection, a record of the physician's evaluation must be on file for those employees who indicate a possible medical limitation.
Respirators have limitations.
They cannot adequately protect a person from all contaminants under all conditions. The protection factor measures the protection provided to the wearer and indicates the efficiency of the respirator in reducing airborne contaminants inhaled. Air-purifying respirator cartridges or canisters have a limited capacity to protect against toxic gases and vapors in the air. Then inspect your respirator for any physical failure. You must change the respirator cartridge or canister if you detect no physical problems.