The Responder PAPR has an industry leading motor blower for constantly filtered airflow and is ideal for first BLOWER, PAPR, C420, W/30" BREATHING TUBE. This manual provides instructions for the use and maintenance of the Sperian SC420 Powered. Air-Purifying Respirator (PAPR) with the Opti-Fit™ Gas. The C420 PAPR has no user-serviceable parts except as instructed in this manual. 19. DO NOT drop the C420 PAPR. If the C420 PAPR is dropped leave the The Scott Safety C420 Plus PAPR can be used for CBRN and non-CBRN applications. It is for fire departments, law enforcement and federal first responders fo. Scott Health and Safety (2005) Brochure for C420 PAPR, Powered Air Purifying Operation and Service Manual, P=N 1980092, Revision M, August 2006,The C420 Continuous Air Supply Unit (CASU) is the most widespread design of a blower unit for Powered Air Purifying Respirator (PAPR) mask ensembles. C420 PLUS PAPR is ideal for fire departments, law enforcement and federal first responders for protection against CBRN related incidents.