Question

On a class charlie fire, what portable firefighting extinguisher should be the last resort?

1) Water
2) Carbon Dioxide
3) Dry Chemical
4) Foam

Answer 1

Water should be used as a last resort for Class Charlie fires, which involve electrical equipment. Carbon Dioxide or dry chemical extinguishers are preferred due to their non-conductive properties.

Step-by-step explanation:

On a Class Charlie (electrical) fire, the portable firefighting extinguisher that should be used as a last resort is water. Class Charlie fires involve electrical equipment, and water conducts electricity, which could pose additional hazards such as the risk of electrocution.

Instead, Carbon Dioxide (CO₂) or dry chemical extinguishers are generally preferred because they don't conduct electricity and are effective in putting out the fire. Foam extinguishers are also not recommended for electrical fires as they can conduct electricity due to the water content.

Carbon Dioxide extinguishers work well as they displace oxygen and extinguish the fire without leaving residue that could harm sensitive electrical equipment.