BS 8468-3.2:2020 pdf free.Respiratory protective devices for use against chemical, biological, radiological and nuclear (CBRN) agents Air-purifying devices incorporating a hood for escape一Specification. BS 8468-3.2 This British Standard specifies the requirements for air-purifying devices incorporating a hood intended to be used only during escape by emergency responders (e.g. fire, ambulance, police) and adult civilians from areas contaminated by chemical, biological,...