Dry Chemical powder extinguishers utilize a specially silicon zed Sodium Bicarbonate. It chemically insulates class B , C fires by forming a cloud and cutting off the oxygen supply, thus extinguishing the fire. It smothers and breaks the chain reaction of Class B fires and will not conduct electricity back to the operator. Features Multi-purpose application Squeeze grip operation Complete with Bracket Corrosion resistant finish Kitemarked to BS EN3* Protective plastic base (Excludes models up to 2kg).