What type of fire extinguisher poses a suffocation threat if used in a confined area?

Answer 1

A dry chemical fire extinguisher might be the best choice for confined spaces. The powder isn't particularly pleasant to breathe, but could be fairly well filtered through a hankie or bandanna across the nose. The carbon dioxide (CO2) extinguisher might displace the air (and the oxygen) in the space and render the would-be firefighter unconscious. The results may be fatal. In any case, attempting to suppress a fire in a confined space is something that should be approached with great care by anyone who is not trained or equipped (clothed, including breathing apparatus) to do the job safely.

Answer 2

That really depends on the type of material that is being burnt.

In the US their are 5 classes of fires; 'A', 'B', 'C', 'D', and 'K'

'A' would be ordinary combustibles (things that would be in a campfire).

'B' would be flammable liquids and gases.

'C' would be electrical equipment.

'D' would be combustible metals.

And 'K' would be cooking oil or fat.

Answer 3

CO2 and "clean agent" extinguishers (e.g., Halon flooding systems) work by excluding oxygen from the flaming surface of a fire, which may also cause the oxygen in the air to reach levels that are unable to support breathing by humans or other animals.

Some types of foam could also, in theory, result in suffocation, or a type of "drowning", if the victim's airway is buried in the foam.