A study by the University of Southern California estimates hundreds of thousands of pounds of toxic metals have been dumped onto forests during aerial fire retardant drops during the past decade, and, according to a new federal lawsuit filed against the U.S. Forest Service, could potentially harm wildlife, specifically endangered and threatened species.
The bright red fire retardant, often seen being dumped from large air tankers, contains cadmium, selenium, chromium, and other metals, according to the lawsuit, which was filed by the Forest Service Employees for Environmental Ethics on May 7. The organization is anon-profit made up of current and former USFS employees dedicated to protecting the country’s forests and reform within the agency.
“This stuff is astonishingly dirty,” said Andy Stahl, the executive director of the organization. “Why the hell are we using such a dirty retardant?”
The chemicals found in some retardants can also be fatal to aquatic life and high concentrations of the metals can be toxic to humans, too. The lawsuit focuses on the effect on wildlife, alleging the federal agencies are violating the Endangered Species Act.
“At the risk of doing the regulatory agencies' job for them, Plaintiff points out the obvious – toxic metals in aerial retardant are bad for many Threatened and Endangered species,” the lawsuit reads.
The National Marine Fisheries Service and the U.S. Fish and Wildlife Service are also defendants in the lawsuit. The U.S. Forest Service did not respond to a request for comment.
The plaintiffs are seeking acknowledgement and disclosure of the toxic metals being used, as well as biological opinions from other agencies assessing the impact of the fire retardant on threatened and endangered animals.
The USC Study, which is referenced in the lawsuit, was published in 2024 after researchers bought fire retardant and put it in a mass spectrophotometer to determine the chemical make-up of the retardant.
“Based on information and belief, the Forest Service has known about the presence of some, or all, of these metals in aerial fire retardant since well before the publication of the USC study,” the lawsuit reads.
The study estimated that between 2009 and 2021, about 840,000 pounds of toxic metals were added into the environment due to fire retardant drops in the United States.
Companies only had to disclose part of their retardant formula, according to the study, necessitating the mass spectrometry test. Previous concerns around retardants mostly centered on it containing ammonium polyphosphates, which can kill wildlife.
“They’re the ones who have really blown open this issue that retardant, the Phos-Chek retardant, contains astonishingly high levels of heavy metals like cadmium,” Stahl said. “We’ve suspected that for years.”
‘Most expensive, least effective’
The organization filed the suit in Missoula in part due to its long association with wildland firefighting.
The United States Department of Agriculture has a Technology and Development Center in Missoula, which includes a lab where fire retardants are tested and certified. Missoula has been at the center of aerial firefighting since the 1940s.
“Missoula tends to be a focal point with fire retardant,” said Jack Cohen, a retired U.S. Forest Service fire research scientist with decades of fire experience.
He also worked at the Missoula Technology and Development Center and doesn’t think fire retardant’s work.
“It’s just about the most expensive, least effective mechanism of fire suppression,” Cohen said.
Drops can be impacted by winds, which can also ground aircraft in the first place. Embers can also move over retardant lines and in a famous example, jumped over a six-lane interstate near Santa Rosa during a 2017 fire.
Direct attack on a fire, or when firefighters’ objective is to contain the blaze as quickly as possible, is also a combination of people, machines and tools. rarely, if ever, is only one method used to work a wildfire.
Cohen said multiple studies into whether retardant drops have any impact on the perimeter of fires have shown inconclusive results as to whether or not they work.
The assumption that retardant drops are effective is a dangerous notion, especially in legal arguments, Cohen said. In a previous lawsuit filed by the ethics group, a Missoula judge ruled that fire retardant does pollute water, but allowed agencies to continue the practice.
“The judge admitted that that was happening and essentially decided against withholding the use of the retardant based on the statement, something on the order of it is conceivable that greater harm to the environment, people and their property would occur without using fire retardant and that assumes that fire retardant is effective” Cohen said. “And to me, that’s very troubling.”
For Stahl, the drops are often about optics and he went on to say the vast majority of aerial retardant drops are ineffective. They are also only used on about 5% of fires, he added.
“Some of the Missoula Fire Science researchers have said to me, quietly, we would accomplish the same damn thing if we just put red food coloring into water and dumped it out of airplanes,” Stahl said. “It would look good on CNN. It wouldn’t be bad for the environment, and it would be just as effective in fire suppression.”
‘The cowboy coming over the ridge’
Fighting fires is expected to get more expensive across the country as the climate turns drier and hotter.
Forestry practices in the United States have also focused on suppression, necessitating the armies of firefighters and equipment fire agencies utilize each year. According to the National Interagency Fire Center, the five-year average for suppression efforts in the U.S. is about $3 billion annually.
Prescribed fires, or fires set with the purpose of clearing out fuels or other land management goals, are sometimes used as a tool by fire agencies.
Decades of suppression have left many forests overgrown and full of dead wood, generally regarded in the firefighting world as “fuel” that can make fires more intense.
Prescribed burns seek to take some of that intensity out of wildfires by removing fuels ahead of time.
But there’s a problem there too, Cohen said — the scale of prescribed burns is not nearly enough.
“Prescribed burning is pointless the way we’re doing it now,” Cohen said.
Stahl brought up the example of recent wildfires in Minnesota. Prior to European colonization, the area was an oak savannah that did not have dense forest.
“We’ve committed all the great plains to croplands and have suppressed fire, we now have forests and these in Minnesota and similar northern tier states that used to be savanna, oak grasslands, and those forests when the humidity is low and the wind is high, which, by the way, means the airplanes that dump either water or retardant can’t fly. We get these fires, and they got lots to burn, a lot of biomass to burn.”
To address the issue, Cohen said the focus should be on building and planning. He views community wildfire risk as a structure ignition problem – the way we build makes structures too easily burned. He said if more fire resistant buildings are constructed with fire resistance in mind, fire crews can have a better plan to fight fires and fewer structures will be lost.
No community can fully be fireproofed, Cohen said, but that doesn’t mean it hurts to try. The more buildings that are protected, the less limited fire resources are stretched.
“We can reduce the number of ignitions that do occur and can be matched by our fire protection,” Cohen said.
Communities across the country are updating their fire readiness and Montana Sen. Tim Sheehy has made a point of introducing legislation on the topic, including some for aerial response to fires.
The problem for some, though, is whether aerial bombardment is the most effective strategy for fighting wildfires. And whether the cost, both financially and on the environment, is worth it.
“We do it because it looks good on CNN. It’s the cowboy coming over the ridge,” Stahl said. “Everybody’s real excited. And they see the retardant bomber arrive and the red stuff come out of the plane. They think, ‘Oh, my God, we’re saved.’ Yeah, not so much.”
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