A final rule, that became effective on September 26, 2019, provides employers with two new fit testing protocols for ensuring that employees’ respirators fit properly. The new protocols are the modified ambient aerosol condensation nuclei counter (CNC) quantitative fit testing protocol for full-facepiece and half-mask elastomeric respirators, and the modified ambient aerosol CNC quantitative fit testing protocol for filtering facepiece respirators. Both protocols are variations of the original OSHA-approved ambient aerosol CNC protocol, but have fewer test exercises, shorter exercise duration and a more streamlined sampling sequence.
The new protocols add to the four existing in Appendix A of OSHA’s Respiratory Protection Standard, which contains mandatory respirator fit-testing protocols that employers must choose from to protect employees from hazardous airborne contaminants. The rule does not require employers in general industries, shipyard employment and construction to update or replace their current fit testing methods.