Which of the following statements pertaining to fire suppression systems is TRUE?

A.
Halon is today the most common choice as far as agents are concerned because it is highly effective in the
way that it interferes with the chemical reaction of the elements within a fire.

B.
Gas masks provide an effective protection against use of CO2 systems. They are recommended for the
protection of the employees within data centers.

C.
CO2 systems are NOT effective because they suppress the oxygen supply required to sustain the fire.

D.
Water Based extinguishers are NOT an effective fire suppression method for class C (electrical) fires.

Explanation:
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, it is TRUE that water-based extinguishers are NOT an effective
fire suppression method for class C (electrical) fires.
Incorrect Answers:A: Halon is NOT the most common choice as far as agents are concerned. Halon is now known to be
dangerous and no longer produced. Therefore, this answer is incorrect.
B: Gas masks DO NOT provide an effective protection against use of CO2 systems. CO2 systems work by
removing the oxygen from the air. Therefore, this answer is incorrect.
C: CO2 systems ARE effective because they suppress the oxygen supply required to sustain the fire.
Therefore, this answer is incorrect.

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