What Is Ethylene Oxide, and How Are People Exposed?

Ethylene oxide is a man-made flammable gas, according to the Agency for Toxic Substances and Disease Registry. It is mostly used at chemical plants to make ethylene glycol, a chemical used to make antifreeze and polyester, and it is also used to sterilize medical equipment and supplies and food products, and to control insects in some stored agricultural products such as spices and herbs.

ATSDR says exposure of the general population usually involves levels lower than those known to cause health problems, but that people living near industrial facilities that release ethylene oxide to the outdoor air may be exposed to higher levels. Workers where it is made or used, such as hospitals and facilities processing certain herbs and spices, generally have higher exposure. For spices, it says only a small amount of the ethylene oxide used in the US goes to herbs and spices, and because it breaks up into the air, only very small amounts could remain on food, if at all.

ATSDR says workers exposed to high concentrations reported effects such as headaches, memory loss, numbness, nausea and vomiting, and that some studies of the most highly exposed workers, exposed over an average of 10 years or longer, found higher risks of certain cancers, such as some blood cancers and breast cancer, while some studies of workers have not found increases in cancer. The US Department of Health and Human Services has determined that ethylene oxide is known to be a human carcinogen, and the EPA has concluded that inhalation exposure is carcinogenic to humans.