Chapter 5 Auto Shop Safety 59 Copyright Goodheart-Willcox Co., Inc. Fires Type Use Class A Fires Ordinary Combustibles (Materials such as wood, paper, textiles.) Requires... cooling-quenching. Class B Fires Flammable Liquids (Liquids such as grease, gasoline, oils, and paints.) Requires...blanketing or smothering. Class C Fires Electrical Equipment (Motors, switches, etc.) Requires... a nonconducting agent. Class D Fires Combustible Metals (Flammable metals such as magnesium and lithium.) Requires...blanketing or smothering. Soda-acid Bicarbonate of soda solution and sulfuric acid Pressurized Water Water under pressure Carbon Dioxide (CO2) Carbon dioxide (CO2) gas under pressure Foam Solution of aluminum sulfate and bicarbonate of soda Dry Chemical Dry Chemical Granular type material Not for use on Okay for use on Not okay for Not okay for Okay for Okay for Multi-purpose type Ordinary BC type Not for use on Not for use on Not for use on Not for use on Okay for use on Okay for use on Okay for use on Okay for use on Operation Direct stream at base of flame. Direct stream at base of flame. Direct discharge as close to fire as possible, first at edge of flames and gradually forward and upward. Direct stream into the burning material or liquid. Allow foam to fall lightly on fire. Direct stream at base of flames. Use rapid left- to-right motion toward flames. Smother flames by scooping granular material from bucket onto burning metal. A B C A A A A A B C D B B B B C C C C D D D D A D B C A D B C Old New Old New Old New D Old New Goodheart-Willcox Publisher Figure 5-7. There are several different types of fires. Fire extinguishers are rated by the type of fire on which they should be used.