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
Before you start work, find the closest extinguisher and the closest way out. On construction sites, access to all firefighting equipment must be kept open at all times. Never stack material, park a cart or hang gear in front of an extinguisher, even for a few minutes. (29 CFR 1926.150(a)(2))
ASK THE CREW
Who checks our extinguishers, and what do you do if you find one that is empty, damaged or blocked?
From the talk: Fire extinguishers. Read it in full, free, with the questions and the sign-in sheet.