Ethoxyquin is a synthetic antioxidant added to chili powder, ground chili, and paprika as a preservative to retain color. This is the only major function that ethoxyquin use has gained approval for as a direct food additive for human consumption. And according to the FDA, it cannot exceed levels past 100 ppm (parts per million). Ethoxyquin is a yellow liquid with molecular weight 217.3. It is insoluble in water, but soluble in organic solvents and has a boiling point of 123°C to 125°C. As a preservative, it works as well or better than BHA (butylated hydroxyanisole, the synthetic antioxidant used to retard rancidity in foods), yet it is not considered natural or clean-label friendly (can be included on a clear, understandable list of non-artificial ingredients and no added chemicals). Some studies have shown ethoxyquin to be effective in crawfish meal and fish oils as an antioxidant. It works especially well in conjunction with lecithin when preserving oils or fats. It will also inhibit, in bacon, nitrosamine formation at very low levels. These are currently not approved uses in the United States per the Code of Federal Regulations.
Other use and industries
Ethoxyquin is also used in animal feed and as a pesticide to control scalding in pears (scalding is an abnormal condition where a fruit's skin is discolored and wrinkled due to excessive sunlight, gases, etc.) The EPA regulates its use as a pesticide, and the FDA regulates its use in animal feed. For animal feed, ethoxyquin has restricted usage levels. These are based on the amount ethoxyquin remaining in or on the animal or animal product for livestock and also the total amount of ethoxyquin allowed in pet food. Some of the limits are not more than 0.5 ppm in uncooked muscle and not more than 5 ppm on uncooked fat of meat products, excluding poultry. In poultry the residual level allowed is 3 ppm. Ethoxyquin is used in pet food. There has been controversy on the usage of this in pet food due to related health issues including thyroid and kidney problems, reproductive problems, and cancer. Due to these findings, the FDA lowered the level permitted in pet food to 75 ppm. As a pesticide, ethoxyquin is an anti-scalding agent and is used on pears to prevent brown spots. The EPA considers ethoxyquin to be a minor-use chemical because production is less than 25,000 lbs per year. The amount of residual ethoxyquin allowed per FDA on pears is not to exceed 3 ppm.
There are no major health concerns with ethoxyquin when consumed at certain levels. It is only permitted at very low levels in food and does not appear to affect health in a negative or positive manner. On the other hand, ethoxyquin is an irritant and can cause dermatitis when handled. It is also an eye irritant, so special precautions should be taken when working with or handling the chemical. Some studies have shown ethoxyquin to cause kidney damage in rats, so it should not be consumed alone or in levels higher than those accepted per the FDA due to its toxicity at high levels.
Ethoxyquin is a synthetic compound and can be prepared a few different ways. One way to produce it is from p-phenetidine-acetone. The ethoxyquin is synthesized by reacting the anil via heat with p-phenetidine and toluenesulfonic acid. This reaction has an 85% yield of ethoxyquin. Ethoxyquin was introduced as a pesticide in 1965 as an anti-scald agent for pears and apples. Originally, ethoxyquin was developed by Monsanto in the 1950’s as a stabilizer. Monsanto is a biotechnology company that still developing and selling high performing pesticides.