Multipurpose dry chemical extinguishers are effective on which class of fires?

Multipurpose dry chemical extinguishers are designed to tackle a wide range of fire classes, making them versatile tools in fire safety. Specifically, they are effective on Class A, Class B, and Class C fires. Class A fires involve ordinary combustible materials such as wood, paper, and plastic; Class B fires pertain to flammable liquids, gases, and greases; and Class C fires involve energized electrical equipment.

The correct choice states that multipurpose dry chemical extinguishers are effective against all classes except D (which includes combustible metals like magnesium and sodium) and K (which relates to cooking oils and fats). This highlights their limitations, as they are not suitable for dealing with fires involving these specific materials due to the unique nature of combustion in these classes. For example, using a dry chemical extinguisher on a Class D fire could exacerbate the situation, as the chemicals may react adversely with burning metals.

Thus, understanding the specific applications and limitations of multipurpose dry chemical extinguishers is essential for effective fire firefighting and safety in environments where these fire classes might occur.