... TIME(S)≥6EFFECTIVE DISCHARGE DISTANCE(M)≥3.0MATERIALCarbon Steel Class ACommon combustibles such as wood, paper, cloth, rubber ... . May occur in homes, office buildings, or business. Class BFlammable liquids such as gasoline, kerosene, oil, grease, ... strikes in kitchens, garages, light manufacturing plants and warehouses. Class CLive electrical equipment. Often occurs in computers, motors, wiring ...