Answer :
Final answer:
Foam extinguishers are recommended for Class A and Class B fires which involve ordinary combustibles and flammable liquids. They are not suitable for Class C or Class K fires.
Explanation:
Foam extinguishers are recommended for Class A and Class B fires. These classes include ordinary combustibles like wood, paper, and textiles (Class A) as well as flammable liquids such as gasoline, paint, and oils (Class B). Foam extinguishers work effectively on these types of fires because the fluorinated solution within the foam can spread across the burning surface and extinguish the fire. Such foams are versatile and are widely used to combat large-scale fires involving organic liquids.
It's important to note that foam extinguishers are not suitable for electrical fires (Class C) or fires involving cooking oils and fats (Class K). Previously, certain foaming agents were used in fire extinguisher systems for different applications such as dry-cleaning solvents, but some of these are no longer recommended for use due to environmental and health concerns.
