https://www.3m.com/3M/en_US/p/c/ppe/respiratory-protection/powered-supplied-air/b/scott/
Powered air-purifying respirators (PAPR) and supplied air respirator (SAR) systems and components incorporate head and body gear to either purify the...
supplied air respiratorsunited statesscottpowered
https://www.cdc.gov/niosh/docket/archive/docket083A.html
NIOSH is working to develop appropriate standards and test procedures for respiratory devices used to protect workers in hazardous environments
supplied air respiratorsdocketnioshcdc