NCCER Millwright Practice Exam 2025 – The Comprehensive All-in-One Guide for Exam Success!

A CO2 fire extinguisher is recommended for a lubricant store room primarily because lubricants can be flammable liquids, which fall under Class B fires. CO2 extinguishers work by displacing oxygen in the area of the fire, effectively suffocating it. They do not leave any residue, making them ideal for use in environments where sensitive materials such as lubricants are stored, as the residue from other types of extinguishers could contaminate the products or cause damage.

Additionally, CO2 extinguishers are safe for use on electrical fires, which may be relevant in a store room where electrical equipment could be present. This versatility makes them suitable for environments that may have multiple types of fire hazards, including those often found in a lubricant storage area.

It's also important to recognize that other types of extinguishers would not be as appropriate in this setting. For example, a Class D extinguisher, specifically designed for combustible metals, would not be relevant, as lubricants do not typically fall into this category. Whereas a Class A extinguisher, used for ordinary combustibles like wood and paper, would not effectively address flammable liquid fires. Similarly, a Class B extinguisher exists but the CO2 type offers the