This British Standard specifies requirements for closed-circuit breathing apparatus (CCBA) intended to be used during fire-fighting, rescue, evacuation, escape, hazard containment and decontamination, and similar activities by emergency responders (e.g. fire, ambulance, police, and associated civilian agencies and workers) in areas containing and contaminated by chemical, biological, radiological and nuclear (CBRN) agents.

This British Standard is applicable to type CBRN1 and type CBRN3 devices. Type CBRN1 devices provide resistance to gaseous chemical agent permeation and penetration and protection capability against hazardous particulate matter. Type CBRN3 devices provide an enhanced level of resistance to liquid and gaseous chemical agent permeation and penetration.

This British Standard contains requirements for classification, testing and marking of the device.