https://laist.com/news/climate-environment/how-much-toxic-heavy-metal-is-in-that-bright-red-fire-retardant-we-had-it-tested-to-find-out Support for LAist comes from Become a sponsor LAist logo Local and national news, NPR, things to do, food recommendations and guides to Los Angeles, Orange County and the Inland Empire Donate * The Brief * AirTalk * News + Criminal Justice + Housing and Homelessness + Civics & Democracy + Transportation and Mobility + Los Angeles Olympics 2028 + Climate and Environment + Gardening & Outdoors + Health + Education + Food + Explore LA + Arts and Entertainment + LA History + Orange County News + Criminal Justice + Housing and Homelessness + Civics & Democracy + Transportation and Mobility + Los Angeles Olympics 2028 + Climate and Environment + Gardening & Outdoors + Health + Education + Food + Explore LA + Arts and Entertainment + LA History + Orange County News * Imperfect Paradise * Podcasts * All Radio Programs * Events * Newsletters * Support Us + Ways to Support + Become a Sustainer + Make a One-Time Gift + Update Your Credit Card + Donate Your Vehicle + Make a Gift of Stock + Make an IRA Charitable Donation + Include LAist in Your Will + Business Membership Program + Member Benefits + Annual Gala + Corporate Sponsorship + Ways to Support + Become a Sustainer + Make a One-Time Gift + Update Your Credit Card + Donate Your Vehicle + Make a Gift of Stock + Make an IRA Charitable Donation + Include LAist in Your Will + Business Membership Program + Member Benefits + Annual Gala + Corporate Sponsorship * About Us + Mission + Board of Trustees + Regional Advisory Council + Leadership + Staff + Diversity, Equity, and Inclusion + Partnerships + Press Releases + Advertising Policy + Jobs + Editorial Ethics & Guidelines + Contact Us + Become an LAist Source + Republishing Our Work + How To Listen + Support Us + Annual Gala + Public Files + Mission + Board of Trustees + Regional Advisory Council + Leadership + Staff + Diversity, Equity, and Inclusion + Partnerships + Press Releases + Advertising Policy + Jobs + Editorial Ethics & Guidelines + Contact Us + Become an LAist Source + Republishing Our Work + How To Listen + Support Us + Annual Gala + Public Files Stay Connected instagram facebook LAist is part of Southern California Public Radio, a member-supported public media network. Menu LAist Listen Donate * News * Listen * Donate A long trail of red follows an airplane over hills. Retardant is dropped over the Palisades Fire. What's in that bright red cloud? ( David Swanson / AFP via Getty Images ) Climate and Environment What's in that bright red fire retardant? No one will say, so we had it tested An LAist investigation found toxic heavy metals in samples of fire retardant collected from the Palisades, Eaton and Franklin fires. Here's what that means. By Jacob Margolis Published Apr 3, 2025 5:00 AM Share This * Facebook * Twitter Keep up with LAist. If you're enjoying this article, you'll love our daily newsletter, The LA Report. Each weekday, catch up on the 5 most pressing stories to start your morning in 3 minutes or less. [ ] Sign Up Not long after the Palisades Fire broke out Jan. 7, firefighting aircraft began drawing bright red lines with fire retardant across the Santa Monica Mountains, in an effort to slow and contain the flames. By the time the fire was out about three weeks later, the MD-87s, S-2Ts and mammoth DC-10s had performed more than 280 drops across 20 square miles, according to data from Cal Fire obtained via public records requests. LAist partnered with researchers at USC to test samples of the fire retardant gathered from fire zones in the weeks after the Palisades, Eaton and Franklin fires where it remained on the ground. Those tests found toxic heavy metals including lead, arsenic, cadmium and chromium, which can accumulate in the environment and pose risks to humans and wildlife, according to federal and state environmental agencies. Support for LAist comes from Become a sponsor A plane dropping a large cloud of red fire retardant in the air over homes. Fire authorities say retardant is a critical component of the firefighting arsenal. ( Mario Tama / Getty Images ) A person watches a plane off in the distance drop fire retardant on the Palisades Fire. Tests USC conducted on LAist's behalf found the presence of heavy metals in unused retardant and in samples collected after the recent fires. ( Allen J. Schaben / Los Angeles Times via Getty Images ) A product called MVP-FX, a variant of Perimeter Solutions' Phos-Chek, was the primary aerial retardant dropped on the Eaton and Palisades fires, according to the company. The presence of heavy metals in MVP-Fx has not been previously reported. LAist shared the USC lab results with Perimeter Solutions. Jeff Emery, Perimeter's president of global fire safety, said the company's products, including Phos-Chek MVP-Fx, have passed extensive testing. He added that the amount of heavy metals found by LAist was far below limits set by the Environmental Protection Agency and "any concerning levels for human health and safety." The presence of heavy metals isn't noted in safety documents publicly shared by Perimeter Solutions. Aircraft often drop more retardant than water each year on fires in California. From 2006 to 2024, more than 194 million gallons of various types of fire retardant were dropped by aircraft, according to data from Cal Fire. "We don't check into every single thing that's in there," said Chris Jurasek, deputy chief of tactical operations at Cal Fire. Support for LAist comes from Become a sponsor He said his agency relies on the U.S. Forest Service to test and verify the safety of the retardants it uses. The use of fire retardants is a "critical" component of the firefighting arsenal, according to both Cal Fire and the U.S. Forest Service. More LAist watchdog reporting * A Black woman sits at a dais with a flag in the background. A name placard in front of her reads: Dr. Va Lecia Adams Kell[um]. Housing and Homelessness Head of LA homeless services resigns days after county votes to pull $350M from troubled agency * A man in a suit jacket and tie looks off to the side, as the name "Andrew Do" appears on a name tag next to the official seal of County of Orange, California. "Vice Chairman, District 1," is written underneath the name. Civics & Democracy Alleging 'special treatment,' OC supervisors push for longer sentence for Andrew Do * Evelyn Douglas, who is 79, stands in front of a burnt out car in the carport directly beneath her apartment. Walls in the carport are charred, and outside of the frame there are holes burnt in the ceiling. News An LAFD and LA County firefighter brawled at the scene of a fire. Here's what we know Why we had to run our own tests Late last year, LAist requested samples of MVP-Fx from Cal Fire, the U.S. Forest Service and Perimeter Solutions, which manufactures the product, for the purpose of running an independent analysis for heavy metals. All declined. "It's not in our interest to share product with public or private agencies," Jurasek said at the time. "You are not the first person to ask for us to give them fire retardant. It happens. It's not something we do." Plants covered in pink powder. Fire retardant coats laurel sumac in the Santa Monica Mountains after the Palisades Fire. ( Jacob Margolis / LAist ) A person's hand holding a bag of leaves covered in red flakes with pink vegetation in the background. A bag of laurel sumac covered in Phos-Chek, gathered in the Santa Monica Mountains. It was later taken to USC for testing. ( Jacob Margolis / LAist ) So over the next few months we gathered our own samples from the field. Support for LAist comes from Become a sponsor After the Franklin, Eaton and Palisades fires were under control, I hiked to remote sites and collected vegetation, trash and dirt that had been caked with fire retardant. The samples were placed into baggies and taken to the Environmental Chemistry Laboratory at USC, where the fire retardant was tested for heavy metals. Marella Schammel, a Ph.D. student, scraped dried red flakes into tubes filled with a diluted mixture of nitric acid and ran them through an inductively coupled plasma mass spectrometer. Test tubes in a tray. Flakes of Phos-Chek were scraped into tubes along with diluted nitric acid for testing. ( Jacob Margolis / LAist ) Arsenic, cadmium, chromium, copper, manganese, nickel, lead, antimony, thallium, vanadium and zinc were all found in the samples. Emery told LAist that any trace heavy metals found in testing were "naturally occurring." Phos-Chek MVP-Fx is primarily made of ammonium phosphates, which are derived from phosphate. That rock, when mined, can contain trace amounts of heavy metals. "There are no heavy metals added to any of our formulations," Emery said. Support for LAist comes from Become a sponsor Cal Fire, the U.S. Forest Service and Perimeter Solutions all dismissed the results of the testing -- saying that the samples couldn't be relied on because they were gathered in the field. That the potential for contamination by ash from burning structures and brush after the retardant was dropped from planes was too great. Eventually, LAist obtained unused, unmixed MVP-Fx and verified the source and authenticity of the material. What we found A person holding a tube with a red liquid. Marella Schammel, a Ph.D. student at USC, prepares samples of Phos-Chek for testing. ( Jacob Margolis / LAist ) Test tubes in a machine. Samples of Phos-Chek loaded into an inductively coupled plasma mass spectrometry machine for testing. ( Jacob Margolis / LAist ) Like the materials collected in fire zones, this unused sample was sent to the USC lab. Schammel processed the MVP-Fx and found the same heavy metals present as the field samples we gathered. There were some differences. However, it's unclear if those differences are due to contamination on the ground or if there's a variance in the amount of heavy metals present in different batches of the product. table visualization "I'm not too surprised," said Daniel McCurry, professor of civil and environmental engineering, who oversaw the testing process. Last year he and Schammel analyzed another Phos-Chek variant -- LC95 -- and found heavy metals as well. LC95 is one of several USDA approved retardants in use today and one of the variants manufactured by Perimeter Solutions. Cal Fire doesn't use the LC95 variant. Those results -- from tests sparked in part by questions I'd asked McCurry in 2019 about whether we should be concerned about what was in fire retardants -- made me want to know more about what is in the fire retardants in use now. In an effort to compare USC's test results to the official safety testing required by the federal government, LAist reached out to both Perimeter Solutions and the U.S. Forest Service, an agency within the USDA, for detailed test results for MVP-Fx. Neither would provide them. In a statement, the U.S. Forest Service said that retardants that qualify for use have to show "nondetectable or trace levels" of certain heavy metals. However, the test results are proprietary information protected by nondisclosure agreements. 'Let people know what they're dealing with' LAist's review of publicly available documentation related to MVP-Fx, including its safety data sheet -- which is required to warn those who may come in contact with the product of potential risks -- found no reference to the presence of heavy metals. A plane dropping red fire retardant on a green hill with flames in the background. A firefighting aircraft drops fire retardant as the Palisades Fire burns amid a powerful windstorm in January. ( Mario Tama / Getty Images ) After reviewing LAist's results and the company's safety data sheet, Claudia Polsky, director of the Environmental Law Clinic at UC Berkeley School of Law, said the company is likely in violation of multiple California laws and regulations including Cal OSHA standards, unfair competition law and Proposition 65. "The Cal OSHA hazard communication standards require that a safety data sheet identify every hazardous ingredient in the product," Polsky said. "Companies often resist disclosure requirements. "To me this situation is disturbing if unsurprising." When asked about the safety data sheet, Emery said that the company works to "ensure compliance with all applicable regulatory requirements concerning our product." A firefighter standing in front of vegetation coated in fire retardant. A firefighter stands amid vegetation covered in retardant in the hills of Mandeville Canyon in January. ( Valerie Macon / AFP via Getty Images ) Some who regularly work with Phos-Chek said that LAist's findings were a surprise to them. " The heavy metal thing, I can tell you, was news to me," said Joel Lane, air tactical group supervisor with the Orange County Fire Authority. He's worked in the industry for decades and has come in contact with different variants of Phos-Chek, both during preparation and when it's been dropped on him by aircraft. Lane said that he's never been told or read in official documentation that heavy metals could potentially be present in retardant, which he finds upsetting. He said the lack of transparency is concerning, but that it wouldn't be the first time. Lane feels firefighters were left in the dark about the risk of PFAS -- long-lasting chemicals used in firefighting foam and in the heavy gear firefighters wear -- that have been tied to elevated rates of cancer, according to the Environmental Protection Agency. Lane himself recently survived prostate cancer. " Be transparent, be open. Let people know what they're dealing with," Lane said. It's only then that they can make informed decisions about risks for themselves, he added. LAist asked the U.S. Forest Service about potential risks to firefighters, to which they responded that "risk assessments of firefighter exposure to retardants do not indicate an increased risk for health effects," pointing to a health assessment conducted by the agency, which includes MVP-Fx. Although the assessment says risks are expected to be generally negligible, it doesn't explicitly mention heavy metal exposure. The U.S. Forest Service didn't respond to whether heavy metal contamination was taken into consideration for the assessment. Widespread safety concerns after the fires * As recent fires burned whole neighborhoods, thousands of homes were destroyed, leaving behind a toxic stew of materials from lead paint in older homes, wiring, batteries and other hazardous substances. The aftermath has been a concern for many in the region looking for a path to rebuilding. Read more: + After LA's wildfires, firefighters show high levels of toxic metals in their blood + Air, soil, water and dust: New study focuses on long-term health impacts of LA wildfire pollution + Researchers tested sandboxes and street dust for lead after the Eaton Fire. Here's what they found What's the risk to you? Heavy metals can pose a serious health risk and have been tied to increased rates of cancer, as well as reproductive and developmental issues in humans. That said, multiple health experts told LAist that the risk to members of the public exposed to the retardant when doing activities like hiking, is likely low, given the concentration of contaminants present in our samples. "It should not be a reason for panic, but maybe it's a reason for caution," said Dr. Ana Navas-Acien, professor and chair of Environmental Health Sciences at the Mailman School of Public Health at Columbia University, who reviewed the results. A yard full of toyws is covered in a red substance. Retardant coats a playground at a Mandeville Canyon home after the Palisades Fire. ( Valerie Macon / AFP via Getty Images ) Pool furniture covered in red retardant. Fire retardant covers a pool and lounge chairs dropped from a firefighting aircraft. ( Justin Sullivan / Getty Images ) Sanjay Mohanty, associate professor of civil and environmental engineering at UCLA, agreed, saying that the risk for people with limited exposure, such as homeowners or hikers, is "very low." If you or your pets are exposed, it's a good idea to wash it off. Environmental effects A sign for the "Santa Monica Mountains Conservancy Zone Parkland" covered in pink retardant. Retardant is a particular concern if it gets into aquatic ecosystems. ( Valerie Macon / AFP via Getty Images ) Fire retardants can be particularly dangerous to aquatic ecosystems, according to a U.S. Forest Service environmental impact study published in 2011. Once retardant enters waterways it can lead to elevated ammonia levels, which in turn can be toxic to salmon and trout. And there's a possibility that an influx of nutrients from retardant can boost algal growth and create dead zones, killing off organisms there. Because of these risks, the U.S. Forest Service prohibits the dropping of retardant within 300 feet of waterways, though it does happen. There have been more than 240 intrusions since 2012, according to another U.S. Forest Service environmental impact study from 2023. However, even if the retardant doesn't get dropped directly on waterways, it can get washed into them by rain. Heavy metals can settle in streams and ponds and potentially have devastating impacts on organisms there. William Clements, a professor in the Department of Fish and Wildlife Conservation at Colorado State University, homed in on the cadmium LAist found in the MVP-Fx. " If even a small fraction of that ends up in that stream, that is cause for concern," he said. An air tanker drops fire retardant on a ridge behind homes burned in the Eaton Fire. If you or your pets are exposed to fire retardant, it's a good idea to wash it off. ( David McNew / Getty Images North America ) The heavy metal can get taken up by sponge-like algae, which is then eaten by aquatic insects such as mayflies and stoneflies, which can die when exposed to the cadmium. Exposure to the heavy metal can also inhibit their reproduction, growth and ability to emerge from streams, compromising a source of food for fish and birds, according to Clements. " The levels of metals will increase and will be bioconcentrated over time. Not now, but in a year, two years, maybe five years from now," said Dmitri Deheyn, a marine toxicologist at the Scripps Institution of Oceanography. " People need to make the association that the impact is a lingering impact that will be diffused and diluted over time and space." In an effort to figure out how much heavy metal was spread throughout the San Gabriel and Santa Monica mountains during the Eaton and Palisades fires, LAist requested information on the total number of gallons of retardant dropped, from both the U.S. Forest Service and Cal Fire, via records requests. None were fulfilled. If you're in the firefighting world and have any samples of Phos-Chek or another type of fire retardant you'd like to share, please reach out. Local news needs you! At a time when trusted news and information are more important than ever, your donation ensures that LAist can continue to serve everyone in our community. Make a powerful statement that you value quality reporting from LAist and safeguard the future of public media today with your gift. Donate Now (*) Monthly Donation ( ) One-Time Donation ( ) $5/mo (*) $10/mo ( ) $15/mo ( ) $20/mo ( ) [ ] ( ) $60 (*) $120 ( ) $180 ( ) $240 ( ) [ ] Continue Most Read * Two fuzzy grey eaglet chicks are huddled together inside a nest as an adult eagle feeds them. Climate and Environment One of Jackie and Shadow's chicks has died. Volunteers tell fans: 'Grieve and feel whatever you feel' Friends of Big Bear Valley, the nonprofit that manages the popular YouTube livestream of the nest, confirmed the news Saturday. * Several people shovels dig into dirt to plant trees; one person holding up a young tree, covering its roots with soil Climate and Environment Thousands of trees will go unplanted in Los Angeles after Musk pulls funding Tens of millions of dollars in grants were withdrawn across the country, targeting programs that plant trees in low-income communities. * A burning hillside with powerlines within the flames is seen with smoke rising into the night sky. Climate and Environment LA County and two cities sue SoCal Edison over damage from deadly Eaton Fire The lawsuits allege that SCE's equipment caused the fire that destroyed swaths of Altadena, prompting massive emergency response and ongoing cleanup costs. * A gated up beige single story house with crumbling walls and foundation. Climate and Environment Rancho Palos Verdes homes continue to slide into the ocean, but the destruction could have been avoided For years, experts warned against developing the unstable cliff top, but property owners prevailed. Now they're paying the price. * A model train track with no train on it behind white picket fence. Climate and Environment His house survived the Eaton Fire -- for now, he's figured out a way to stay Rob Caves and his partner's Christmas Tree Lane home survived the Eaton Fire, like the majority of houses on his block. But with ash in the air and no drinkable water, few of his neighbors have returned. * Pacific Coast Highway during day. A crane, workers, and many cones are in the middle of the road. Burned remains of buildings are on the left, with a view of the burned hillside in the middle of the frame. Climate and Environment Hours before planned Palisades' public reopening, Bass reverses course Reopening of the Palisades was scheduled for 8 a.m. Sunday. But on Saturday night, L.A. Mayor Karen Bass said checkpoints will remain in place, after she secured additional law enforcement resources from Gov. Gavin Newsom. Best of LAist * I just couldn't get comfortable with hearing only one side of an issue * As LA veers toward a financial crisis, $320M in liability payouts play a big role * Searing audit finds city of LA has failed to properly track billions in homelessness spending * OC treasurer threw keys at subordinate, violating workplace violence policy, investigation found * LA's top homelessness official signed $2.1 million contract with husband's employer * Asking rents skyrocket as LA fires destroy homes Keep up with our local independent news The L.A. Report newsletter is your daily morning update on the biggest stories in the Los Angeles region. [ ] Sign Up LAist Stay Connected instagram facebook LAist is part of Southern California Public Radio, a member-supported public media network. * About Us * LAist Staff * Careers * Advertising * Contact Us * Support Us * Newsletters * Editorial Ethics & Guidelines * Diversity, Equity, and Inclusion * EEO Public Reports * FCC Public Files KPCC-FM * FCC Public Files KUOR-FM * FCC Public Files KVLA-FM * FCC Public Files KJAI-FM * FCC Applications Public Notices (c) 2025 Southern California Public Radio - All Rights Reserved Terms of Service Privacy Policy Play Live Radio Next Up: 0:00 0:00 Available On Air Stations * On Air Now Playing LAist 89.3 Listen * On Air Now Playing LAist 89.3 Special Coverage Listen All Streams