Introduction : Dry chemical is a powder mixture which is used as a fire extinguishing agent. It is intended for application by means of portable extinguishers, hand hose line systems, or fixed systems. The following types of dry chemical powder are generally used: " CLICK to view:- Seminar on Dry chemical powder " a) Borax and sodium bicarbonate based dry chemicals were the first such agents developed. Sodium bicarbonate became the standard because of its greater effectiveness as a fire extinguishing agent. b) Now sodium bicarbonate base dry chemical was modified to render it compatible with protein based low expansion forms to permit a duel agent attack. c) Multipurpose (mono-ammonium phosphate base) and "purple-K" (potassium bicarbonate base) dry chemicals then were developed for fire extinguishing use. d) Shortly there after, "Super-K" (Potassium chloride base) was developed to equal "purple-K" in effectiveness. Dry chemical is...