Which fire class can water be most appropriate for?

A.
Class A fires

B.
Class B fires

C.
Class C fires

D.
Class D fires

Explanation:
Class A fires can be extinguished with water. Class A fire extinguishers use water or foam.
Class A fires involve “common combustibles”; these are ordinary combustible materials, such as cloth, wood,
paper, and many plastics.
Incorrect Answers:
B: You cannot use water on a Class B fire. A Class B fire is a flammable liquid fire such as gasoline, oil or
lacquers. Therefore, this answer is incorrect.
C: You cannot use water on a Class C fire. Class C fires are Electrical fires. Therefore, this answer is incorrect.
D: You cannot use water on a Class D fire. A Class D fire is combustible metals such as magnesium or
potassium. Therefore, this answer is incorrect.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, p. 472