Final answer:
A multipurpose dry chemical fire extinguisher should NOT be used on fires involving aluminum shavings, as it can cause a dangerous reaction making the fire worse. It is suitable for use on paper fires, overheated motors, and paint thinner fires. Understanding the right fire extinguisher for each situation is crucial for safety.
Step-by-step explanation:
A multipurpose dry chemical fire extinguisher should not be used on certain types of fires due to the chemical reactions that may occur. For example, aluminum shavings can react with the extinguishing chemicals in a way that could exacerbate the fire.
In contrast, paper ignited by a faulty electrical plug, an instrument motor overheating, or paint thinner ignited by a cigarette, all represent types of fires that a multipurpose dry chemical extinguisher is generally equipped to handle.
Specifically, the use of a dry chemical fire extinguisher on aluminum shavings can be dangerous. When you introduce certain dry chemicals commonly found in these types of fire extinguishers to burning metals such as aluminum, you risk a reaction that produces additional heat and potentially more intense flames, making the situation worse.
It is always important to follow instructions carefully on how to handle flammable chemicals and to understand the appropriate type of fire extinguisher for each class of fire. This knowledge is crucial for ensuring safety and preventing the escalation of a potentially dangerous situation.