Colorado CDL Practice Test

What type of extinguisher is suitable for electrical equipment fires?

1. Water-based extinguishers

2. Dry chemical extinguishers

3. Foam extinguishers

4. Wet chemical extinguishers

The correct answer is: Dry chemical extinguishers

Dry chemical extinguishers are suitable for electrical equipment fires because they effectively put out fires involving energized electrical equipment without conducting electricity. These extinguishers typically contain agents such as monoammonium phosphate or sodium bicarbonate, which smother the fire and disrupt the chemical reaction that fuels it. Using water-based extinguishers on electrical fires is dangerous, as water conducts electricity and can lead to electrocution or further complications in suppressing the fire. Foam and wet chemical extinguishers are also not appropriate for electrical fires; foam can conduct electricity as well, while wet chemical agents are more suited for grease and oil fires, like those associated with cooking equipment, and not for electrical equipment. The choice of a dry chemical extinguisher ensures that safety and effectiveness are maintained in a potentially hazardous situation.