MagChloride Truth


PHOS-CHEK Fire Retardants: 60 Years of Continuing Innovation

After working as part of a cooperative effort with the US Forest Service since the mid-1950s, PHOS-CHEK became the first Agency-approved phosphorus-based wildland fire retardant in 1962.

PHOS-CHEK products were the first commercialized gum-thickened retardants with a range of viscosities. Previously, the only options for the fire manager were no-viscosity (un-thickened) or high viscosity retardants. This innovation allowed the using Agencies to optimize retardant characteristics based on the delivery system, topographical situation, fuel and specific fire characteristics.

PHOS-CHEK introduced iron oxide-colored PHOS-CHEK 259-R in 1971. PHOS-CHEK 259 is the only retardant that meets the corrosion requirements for critical magnesium components in helicopters with fixed tanks.

PHOS-CHEK developed and introduced the first “fugitive colored” retardant in 1975. This critical innovation provided fire management agencies the ability to effectively fight fires in aesthetically sensitive areas such as National Parks and wildland-urban interface areas, where iron oxide-colored retardants were less desirable or unacceptable. Fugitive colored retardants also reduced the risk of staining private property, airport runways, taxiways and other exposed areas. PHOS-CHEK fugitives today remain the only “true-fugitive” fire retardants where the red color disappears in less than a month.

PHOS-CHEK commercially introduced retardants based on a synergistic blend of ammonium sulfate and ammonium phosphates in 1985. This blend provides fire retardant performance similar to ammonium phosphate retardants at a considerably lower cost. This phosphate/sulfate retardant blend was later eliminated in favor of a full phosphate formulation that provided more favorable environmental effects.  This is just one example of the continuing evolution of more effective, more environmentally responsible formulations.

All PHOS-CHEK fire retardants are available and qualified for use in ground engines and other ground application apparatuses. These retardants give fire management agencies a valuable tool for fire prevention, suppression, and prescribed burning.

As a complement to the chemistry of their fire retardants, Perimeter Solutions pioneered “eductor mixers” that could continuously mix dry-powder retardants at a rate of 21,000 gallons per hour using only one person. Today, Perimeter Solutions offers eductor systems capable of mixing 30,000 gallons of retardant per hour.

Perimeter Solutions offers the most comprehensive set of fire retardant solutions on the market today – featuring technology development, products, services, training and equipment.