Dry Powder Fire Extinguisher by Sk Sons & Associates

The base material used in these extinguishers is ordinary sodium bi-carbonate based dry powder conforming to specifications of IS:4308-1982. The composition of dry powder is Sodium Bicarbonate, Ammonium phosphate, potassium chloride etc. with additives to make it free flowing & water repellant. Dry powder is non-toxic, non-corrosive, non-abrasive and non-conductive to live electrical equipment.
Ordinary dry powder extinguishers are not recommended for the following fires:

1. Fire involving chemicals like cellulose nitrate which have their own oxygen supply.

2. Fire involving combustile metals like magnesium, titanium, zirconium etc.

3. Where dry powder deposition causes damage to sensitive electrical / electronic equipment.

4. In confined areas where temporary reduction in visibility due to discharge powder may jeopardize chances of the people in the room. Article size of the dry powder also effects the performance. Is specifies that 90% of the powder should be below 75 microns.

Applications:
These extinguishers are excellent for 'running' or 3-dimmentional burning liquid or pressurized gas leak fires. Dry Powder is non-conductive hence these extinguishers can be used on Electrical fires. However the insulating properties of the reside caking onto wires and electrical equipment may damage the electrical fittings in salvage operations.
Fires involving fuel falling vertically or a pressurized leak fire going upwards should be fought from bottom first and progressively upwards otherwise the flames leaping from the bottom continuously re-ignites the falling stream. Three dimensional fires should be fought starting from the source of the flammable liquid and in the direction of flow.