Agency for Toxic Substances and Disease Registry
Case Studies in Environmental Medicine (CSEM) 

Ethylene Glycol and Propylene Glycol Toxicity
How Are People Exposed to Ethylene Glycol?

Learning Objectives

Upon completion of this section, you should be able to

• identify the primary route of exposure to ethylene glycol.

Introduction

The primary route of ethylene glycol entry into the body is through accidental or intentional ingestion.

Workers in industries producing or using products containing ethylene glycol are at greatest risk of exposure.

Dermal Exposure

Skin contact is the most likely route of occupational exposure, but dermal exposure is not likely to lead to toxic effects. Skin contact while handling automotive antifreezes, coolants, and brake fluids is not likely to cause adverse health effects under normal conditions.

Inhalation Exposure

Ethylene glycol vapor and mist can be inhaled, particularly when the chemical is heated, agitated, or sprayed. A 1981-1983 National Institute for Occupational Safety and Health (NIOSH) survey found that an estimated 1,133,792 workers were potentially exposed to ethylene glycol (NIOSH 1990).

In one study, prison volunteers were exposed to aerosolized ethylene glycol concentrations of 3-67 mg/m³ (1.4-27 ppm) for 20-22 hours a day for 1 month. The resulting body fluid levels were 1.6-8.4 mg% for urine and 8-21.2 mg% for serum. The participants showed no serious signs of ethylene glycol intoxication, but they did experience nose and throat irritation (Wills, Coulston et al. 1974). No reports of adverse health effects from chronic ethylene glycol environmental exposures were found.

Ingestion

In the general population, ethylene glycol exposure occurs most commonly through ingestion of antifreeze. In the United States, the Toxic Exposure Surveillance System (TESS) prepared by the American Association of Poison Control Centers documented 4,829 cases of ethylene glycol poisonings, 31% experienced toxicity and needed treatment, and 9 cases were fatal in 1996 (Litovitz TL 1997), 2,174 cases treated in health care facilities in 1998 (Litovitz TL 1999), 6,281 ethylene exposures and 23 deaths in 1999 (Litovitz TL 2000), 5562 exposures; 2109 treated; 23 deaths in 2004 (Watson WA 2004).

Who Is at Risk of Exposure?

Workers at greatest risk of exposure are in industries that manufacture or use products containing ethylene glycol, particularly operations involving

• automobile maintenance
• aircraft de-icing

Exposure at Home

In the general population, ethylene glycol exposure occurs most commonly through ingestion of antifreeze. Ethylene glycol exposure in the general population may also result from skin contact while handling

• automotive antifreezes
• coolants
• brake fluids

Such exposures, however, are not likely to cause adverse health effects under normal conditions.

Key Points

• Workers in industries producing or using products containing ethylene glycol are at greatest risk of exposure.
• General population exposures occur most commonly through accidental or intentional ingestion.

Progress Check