For Class C fires, which extinguishers are suitable?

• A. Water-based extinguishers are best
• B. CO2 and dry chemical ABC/BC extinguishers
• C. Wet chemical extinguishers
• D. Class D extinguishers

Answer: (B)

Class C fires involve energized electrical equipment, so you want an extinguisher that won’t conduct electricity and won’t leave conductive residue. CO2 extinguishers are non-conductive and displace the oxygen, making them effective for electrical fires. Dry chemical powders (ABC or BC) are also non-conductive and interrupt the chemical reactions sustaining the flame, which helps in electrical fires. Water-based extinguishers are unsafe on electrical fires because water conducts electricity and can energize the extinguisher or spread the shock risk. Wet chemical extinguishers are designed for cooking fats/oils, not electrical equipment, and Class D extinguishers are for metal fires, not electrical. Therefore, the best choice is CO2 and dry chemical ABC/BC extinguishers.