The U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) today issued a final rule that 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.