Fire extinguisher older models also achieved class B and C fire-fighting capability in the past, current models are rated A:K (Amerex, Ansul, Buckeye and Strike First) or K only (Badger/Kidde). Clean agents extinguish fire by displacing oxygen (CO or inert gases), removing heat from the combustion zone (Halotron-1, FE-36, Novec 1230) or inhibiting the chemical chain reaction (Halons). They are referred to as clean agents because they do not leave any residue after discharge which is ideal for protecting sensitive electronics, aircraft, armored vehicles and archival storage, museums, and valuable documents. Halon was completely banned in Europe and Australia except for critical
Cutting extinguisher smoke diving is reduced. The small size of the access hole also reduces any risk of flashover or backdraft. Flashover is reduced by avoiding the need to open up a large access hole, backdraft by the flow of water through this small hole keeping any flow cooled and directed inwards, towards the fire. Secondary advantages are in gaining rapid access to the seat of the fire, directly through most construction materials and without needing to cause structural damage that may further weaken a structure. The cutting extinguisher technique originates in Sweden, with Cold Cut Systems Svenska AB. Cold Cut Systems