Smoke hood
From Wikipedia, the free encyclopedia
A smoke hood is a protective device similar in concept to a gas mask. A translucent airtight bag seals around the head of the wearer while an air filter held in the mouth connects to the outside atmosphere and is used to breathe. Smoke hoods are intended to protect victims of fire from the effects of smoke inhalation.
High quality smoke hoods are generally constructed of heat resistant material like Kapton, and can withstand relatively high temperatures. The most important part of a smoke hood is the filter that provides protection from the toxic byproducts of combustion. Virtually all smoke hood designs utilize some form of activated charcoal filter and particulate filter to screen out corrosive fumes like ammonia and chlorine, as well as acid gases like hydrogen chloride and hydrogen sulfide. The defining characteristic of an effective smoke hood is the ability to convert deadly carbon monoxide to relatively harmless carbon dioxide through a catalytic process.
Smoke hoods present on aircraft, also called Protective Breathing Equipment (or PBEs), typically generate oxygen for approximately 30 seconds. The oxygen is kept in a closed circuit, usually thanks to a tight neck seal. A scrubber system may be present to reduce the levels of carbon dioxide, and is breathable for around 20 minutes. When the oxygen supply ends, the hood must be removed to avoid suffocation.
