Final answer:
The classification of a fire extinguisher is identified by a letter and color, corresponding to the type of fire it can extinguish. The letters indicate the class of fire - A, B, C, D, or K. The NFPA 704 system further uses color-coded diamonds to indicate a substance's hazards.
Step-by-step explanation:
The classification of a fire extinguisher is identified by a letter and color. These identifiers help users quickly determine the type of fire extinguisher and the class of fires it can safely extinguish. Fire extinguishers are categorized into classes based on the types of fires they are designed to combat, with these classes being represented by letters.
For example, Class A extinguishers are for ordinary combustibles like wood and paper, Class B are for flammable liquids, Class C are for electrical fires, and Class D are for metal fires. There is also a Class K which is suited for kitchen fires involving cooking oils and grease. Each class of extinguisher may also have a color code to aid quick identification.
In addition to the class letters, the National Fire Protection Agency (NFPA) 704 Hazard Identification System uses color-coded diamonds to indicate the level of hazard associated with materials. This system helps identify the flammability, reactivity, health, and other hazards of substances in the case of an emergency.