Is there fire retardant in the fish you eat?

On January 8, 1966, a South African ship caught fire at sea. When it was in port in Bristol, England, firefighters pried open the smoking container, and the conflagration spread and burned for five days. A little over a month later, on February 11, a Liberian steamship caught fire near Rotterdam. The blaze spread and ignited a storage area with barrels of petrol, raging for several days, before melting the deck and mast and eventually sinking the vessel.2 Then, on March 19, 1966, a Danish ship caught fire off Long Beach, California, injuring three firefighters and killing a longshoreman, and causing over a million dollars in estimated damages.

The culprit in each fire was fishmeal, a highly flammable cargo. This dark-yellow powder—made by drying and pulverizing fish for use as animal feed in chicken, pig, and especially aquaculture farms—is known for spontaneously combusting as it decays and oxidizes. From the 1950s through the 1970s, fishmeal cargo ignited at least 90 fires on ships and in plants around the world, according to a sweep of historical news coverage by The Outlaw Ocean Project.

For seafarers, insurers, dock workers, and port firefighters throughout the 1950s and 1960s, fishmeal’s combustibility was a serious worry. One feed manufacturer called it “practically as flammable as gunpowder,” causing fires that are “notoriously hard to control” and that can burn for multiple days, even in a flooded ship’s hold, according to a 1962 article in a Californian newspaper, the Independent. The chairman of the Liverpool Underwriters’ Association, an insurance group, cited fishmeal as a primary reason the 1960s were the “worst in living history” for ship losses in their 1963 annual report of casualty statistics.

But in 1967, American feed producer Cargill announced a solution: a fire retardant called ethoxyquin. A Cargill official told the Los Angeles Evening Citizen News in 1970 that the company had finally found a way to “remove the fire hazard,” solving fishmeal’s primary drawback: “oxidation and resulting heating.”

Ethoxyquin, previously used as a way to keep rubber tires from drying out and as a preservative on fruits and alfalfa, was soon ramped up for production. After a trial shipment of 400 tons of ethoxyquin-treated fishmeal from Peru arrived safely in Florida, Cargill announced plans to ship 100,000 tons of Peruvian fishmeal to the US annually. Their new “AO (for Antioxidant) fishmeal” could now be shipped in bulk and transported “to more distant users in Washington, Oregon, Idaho, Utah, Colorado, and Southern California,” the newspaper reported. (In a statement, Cargill said that since 2005, it has “evaluated alternative antioxidants for use in fishmeal to support transport stability and respond to evolving customer and regulatory expectations” and it does not use ethoxyquin in its global salmon feed business or in any market where ethoxyquin is no longer authorized for use in aquafeed. It also said “antioxidants are applied by fishmeal production facilities before storage and transport; Cargill does not add ethoxyquin to fishmeal after receiving it for aquafeed production.”)

Soon, feed companies marketed ethoxyquin-treated fishmeal as not just safer but also more nutritious. “It’s a fact!” a 1969 Red Rose Poultry Feeds advertisement claimed, “ethoxyquin protects vitamins A and E and pigments in the feed.” A Hubbard Milling Company advertisement added that with their ethoxyquin-containing feed, “the right feed at the right time means more profit for you!”

Most experts agreed that the chemical was highly effective. By the 1970s, press-reported fires dropped sharply—from a typical 16 ship fires a year, according to the Liverpool Underwriters’ Association, to five in 1967. A Florida newspaper wrote that ethoxyquin could “eliminate serious hazards of combustion” and make fishmeal “safe for transportation.” “Antioxidant treatment has made bulk handling an easy matter,” the director of the Canadian Department of Fisheries told an industry publication in 1966, arguing it should be required for fishmeal shipments as it “is the more effective antioxidant,” despite being more expensive. By 1976, the US Coast Guard imposed mandatory ethoxyquin treatment on fishmeal shipments, and three years later, the UN body that oversees maritime activity recommended fishmeal be treated with ethoxyquin “to prevent spontaneous combustion.”

But there was a problem with ethoxyquin: It is carcinogenic.

As early as 1969, a group of UN food and agriculture authorities released a paper noting that “toxic effects had been observed in laboratory animals fed high concentrations of ethoxyquin” and that “occurrence of dermatitis among fruit packers suggests that sensitization could be a problem among those who are handling ethoxyquin.” As its use in animal feeds grew, a 1987 study by British researchers found the chemical “caused severe damage” and had a potentially “carcinogenic effect” in rats. In 2015, the European Food Safety Authority said an impurity within ethoxyquin, known as p-phenetidine, was a possible mutagen, capable of causing mutations in genetic material. Two years later, the European Commission suspended authorization for its use in animal feed across the European Union.

Ethoxyquin has also been banned in the UK and by members of the European Economic Area, including Norway, Iceland, and Liechtenstein. Australia, Japan, South Korea, and the US still permit its use in feed but limit the maximum permissible level. While some countries, such as Peru and Vietnam, have not banned the chemical, their fishmeal industries have responded to the requirements of their major export markets by taking steps to ensure that aquafeed destined for certain parts of the world does not contain ethoxyquin.

While ethoxyquin is not banned in the US, it has been at the center of a half-dozen lawsuits in American courts, typically involving claims of false advertising. In 2019, the NGO Toxin Free USA sued the J.M. Smucker Company and Ainsworth Pet Nutrition in Washington, DC, alleging consumer protection violations for labeling pet food as “natural” and free of “artificial preservatives” despite containing ethoxyquin. In a similar case in 2021, two national nonprofits, GMO Free USA and Clean Label Project Foundation, sued Nestle Purina Petcare Company for marketing cat food as containing “no artificial…preservatives” when it also contained ethoxyquin. Both pet food cases were settled out of court. Also in 2021, a California resident brought a class-action suit against Champion Petfoods USA, alleging false marketing of its pet food as made with “wild-caught fish,” since ethoxyquin is only found in farmed fish. The court dismissed this claim.

Other lawsuits have targeted seafood companies for marketing their products as “sustainable” even though they were found to contain ethoxyquin. Specifically, these cases have highlighted the potential risks that the additive poses to the environment. In 2022, a New York resident brought a class-action lawsuit against Aldi, Inc., a German supermarket chain, alleging its Atlantic salmon products were falsely labeled as “sustainable” due to “environmentally destructive” practices. The complaint cited the EU’s ban on the chemical and a study linking ethoxyquin to mortality and deformations in fish and crustaceans, noting it “poses a risk for aquatic life.” The case was settled out of court. Also in 2022, a New York and a California resident jointly sued seafood company Gorton’s Inc. for labeling its frozen tilapia as “sustainably sourced” despite containing ethoxyquin. This lawsuit also cited the “risk for aquatic life” and the European Union’s ban, and was settled out of court.

Roughly 80 percent of seafood consumed in the US is imported, with China being the biggest supplier. In 2024, the US imported 768 million pounds of seafood from China, more than from any other country, according to trade data by the National Oceanic and Atmospheric Administration.China is also among the biggest global users of ethoxyquin, as Asia is the largest market for feed antioxidants and China is the top regional consumer, according to a 2025 industry report. The chemical’s prevalence is a concern for Beijing as the government works to clean up contamination on fish farms and in the nearshore ocean along China’s eastern coast. In 2018, Chinese researchers studying water pollution found ethoxyquin to be one of the most abundant contaminants in a Yangtze River reservoir that supplies over half the drinking water in Shanghai.

Ethoxyquin is making its way into US-consumed seafood. A review of more than 350,000 weekly FDA inspection reports from 2018-2022 showed trace amounts of the chemical in three seafood types: shrimp, especially from Indonesia and India; salmon, most often from Chile; and tilapia, frequently from China. While the detected levels were always below the amount the FDA deems safe, critics claim this safe level is weak compared to the one in the EU, which bans any amount appearing in food. Though ethoxyquin is also used on fruits and vegetables to slow skin drying, FDA data indicates that seafood is over 10 times more likely to arrive in the US containing the chemical compared to other tested foods, including asparagus, cucumbers, and tomatoes.

Since the EU ban, other antioxidants have been substituted for ethoxyquin, including synthetic chemicals like butylated hydroxyanisole (BHA) and natural additives such as rosemary extract and vitamin E compounds. “More and more destinations are not accepting ethoxyquin, starting with our local Peruvian market,” said James Frank, Managing Director of the Peruvian fishmeal company MSI Ceres, during a 2022 webinar. He added that 100 percent of Peru’s fishmeal exports to Europe, Canada, the US, and Australia are now ethoxyquin-free, a shift also seen among companies in the UK and Norway.

BHA is the most popular alternative to ethoxyquin, favored for its lower costs and strong antioxidant properties over fully natural additives. But, in yet another unfortunate cycle of unintended consequences, this replacement has raised serious concerns. Like the chemical it aims to supplant, BHA has its own significant health risks, according to researchers. The US National Toxicology Program identified BHA as “reasonably anticipated to be a human carcinogen” in 1991, and Japanese researchers found it caused malignant tumors in laboratory rats in 2008.

For the time being, European regulators have deemed BHA safe enough to use. In 2018, a panel from the European Food Safety Authority concluded there was “no concern for consumer safety” when BHA is used as a feed additive below the EU’s established limit of 150 milligrams per kilogram of feed. The US is reassessing the matter; the Food and Drug Administration took a more cautious approach, announcing in 2025 that it would reassess the safety of the substance as a food additive.

Related:

• The Cost of Stench And Who Pays It?
• The Problem of Stench: To Counter It You Must Count It

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This article originally appeared on Foodforfeed.theoutlawocean.com and was syndicated by MediaFeed.co