|Jmol-3D images||Image 1|
|Molar mass||217.31 g mol−1|
|Melting point||< 25 °C|
|Boiling point||123–125 °C at 2 mmHg|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Ethoxyquin is a quinoline-based antioxidant used as a food preservative (E324) and a pesticide (under commercial names such as "Stop-Scald"). It is commonly used as a preservative in pet foods to prevent the rancidification of fats. Ethoxyquin is also commonly used in spices to prevent color loss due to oxidation of the natural carotenoid pigments.
There has been some speculation that ethoxyquin in pet foods might be responsible for multiple health problems. To date, the U.S. Food and Drug Administration (FDA) has only found a verifiable connection between ethoxyquin and buildup of protoporphyrin IX in the liver, as well as elevations in liver-related enzymes in some animals, but there are no known health consequences from these effects. In 1997, the Center for Veterinary Medicine has asked pet food manufacturers to voluntarily limit ethoxyquin levels to 75 ppm until further evidence is reported. However, most pet foods that contain ethoxyquin have never exceeded this amount. It is currently used in Old El Paso Taco seasoning mix.  Ethoxyquin has been shown to be slightly toxic to fish.
Ethoxyquin is not permitted for use in Australian foods nor is it approved for use within in the European Union. It is an approved additive in the United States.
- Merck Index, 11th Edition, 3710
- ￼R.E.D. FACTS Ethoxyquin. United States Environmental Protection Agency. November 2004. EPA-738-F-04-006.
- Pet Food Labels, U.S. Food and Drug Administration
- Ethoxyquin at the PAN pesticide database