The hazard
A fire extinguisher can stop a small fire before it spreads, but only if it is close by, charged and the right type for the fire. Fires grow fast, and smoke can fill a room before you know it. Knowing when to fight a fire and when to get out matters as much as knowing how to pull the pin.
The action
In general industry, where your employer provides extinguishers for employees to use, it must give you education on the general principles of using them and the hazards of fighting a fire in its beginning stage. Workers named in an emergency action plan to use firefighting equipment must also be trained on that equipment (29 CFR 1910.157(g)(3)). Ask for a hands-on demonstration with the extinguishers on this site. (29 CFR 1910.157(g)(1))
ASK THE CREW
What kinds of fires could start in our work area, and do our extinguishers match them?
From the talk: Fire extinguishers. Read it in full, free, with the questions and the sign-in sheet.