The Forest Service is suspending use of a new-age aerial fire retardant after inspections revealed corrosion in two air tankers that were carrying the chemical.
The agency said it won’t use the magnesium chloride-based retardant for the 2024 season, depriving the Forest Service of an alternative to phosphate-based treatments that are toxic to aquatic wildlife.
Routine aircraft inspections after the 2023 fire season revealed significant corrosion in two air tankers used to test the intermingling of chemical retardants, including the magnesium chloride compound made by a company called Fortress.
The initial findings created “an unacceptable level of uncertainty regarding aircraft safety” and spurred the Forest Service to seek further investigation by the National Transportation Safety Board and the National Institute on Standards and Technology, the forest agency said.
