Phos-Chek
ADDPMP742Phos-Chek is a brand of long-term fire retardants manufactured by Perimeter Solutions, headquartered in Clayton, Missouri, US since 1962. It was the first phosphate-based fire retardant to be approved by the United States Forest Service and is now the most used fire retardant in the world.
Phos-Chek products are manufactured as dry powders or concentrated liquids, to be diluted with water prior to use. The phosphate and sulfate salts, part of the composition, act as fire retardants and prevent the combustion of cellulosic materials. Phosphate also acts as a fertiliser once the fire danger has passed. The retardant is applied to homes and vegetation in wildfire-prone areas by ground crews and aerial firefighting units using either fixed-wing or rotary-wing aircraft.
Phos-Chek is produced in several colours, including an off-white colour, red iron oxide and a fugitive mixture that is coloured red when dispersed but gradually fades to an earth tone when exposed to sunlight. The red colour aids aircrews in targeting drops of retardant.
















































































































































































































































































































































































































































































































































































































































































































































































































































