Fire extinguishers need to be recharged periodically throughout their life, even if they haven't been used. ... For the most commonly used stored pressure dry chemical fire extinguishers, this internal examination and recharging is required periodically as per norms.New extinguishing agent (powder, gas, water or foam) is filled in the cylinder through a vacuum based process that fills the cylinder with exact quantity of extinguishing agent.

Water - Class A fires (solid combustibles such as wood, paper and textiles). Some water extinguishers are safe on electrical equipment if di-electrically tested. Otherwise caution is required near electrical equipment, as ordinary water is a conductor.AFFF foam - Class A and B (flammable liquids). Safe on electrical equipment if di-electrically tested. Carbon dioxide (CO2) - Class B and electrical equipment ABC powder - Class A, B, C (flammable gases) and electrical equipment De-Ionised Water mist - Class A, B, C and electrical equipment Wet chemical - Class F (deep fat) fires, sometimes class A