Fire Extinguishers Hazardous Waste Check Regularly Check your fire extinguisher every month to make sure that it is safe to use. The needle should point to the green area of the pressure gauge. If the needle points to the red area, you must replace your extinguisher or have it refilled. Most fire extinguishers only last 5 to 10 years, even if they have never been used. Ways to Reduce Never Test If you spray your fire extinguisher even once, you must replace it or have it refilled.