Quantitative fit testing is the preferred testing method. The ambient aerosol condensation nuclei counting (CNC) method, using a Portacount® Plus instrument, has been selected as the quantitative fit ...
Pursuant to 29 C.F.R. § 1910.134(f) employees are required to be fit tested prior to wearing tight-fitting respirators and the fit test administered must be using an OSHA-accepted fit test protocol.