Under what conditions would the use of a Class C fire extinguisher be preferable to a Class A extinguisher?

A.
When the fire involves paper products

B.
When the fire is caused by flammable products

C.
When the fire involves electrical equipment

D.
When the fire is in an enclosed area

Explanation:
Class C fire extinguishers are used for fires involving electrical equipment.Class C fires are electrical fires which that may occur in electrical equipment or wiring. Class C fire
extinguishers use gas, CO2 or dry powders. These extinguishing agents are non-conductive.
Class A fire extinguishers use water or foam. Water or foam used on an electrical fire would conduct the
electricity and make the fire worse. Therefore, for an electrical fire, a Class C fire extinguisher is preferable to a
Class A fire extinguisher.
Incorrect Answers:
A: For a paper fire, a Class A fire extinguisher that uses water or foam is preferred. Therefore, this answer is
incorrect.
B: All products that are burning in a fire are ‘flammable’. The specific type of product needs to be determined to
determine which fire extinguisher to use. Therefore, this answer is incorrect.
D: For a fire in an enclosed area, a Class A fire extinguisher that uses water or foam is preferred (unless the
elements of the fire require a different fire extinguisher). This is because other fire extinguishers can use gases
that can be harmful to life. Therefore, this answer is incorrect.

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