A report prepared for the World Health Organization in 2000 stated that laboratory tests exposing aquatic organisms to stream water receiving runoff from airports have shown toxic effects and death (p. 12). Field studies in the vicinity of an airport have reported toxic signs consistent with ethylene glycol poisoning, fish kills, and reduced biodiversity, although those effects could not definitively be ascribed to ethylene glycol (p. 12). The process of biodegrading of glycols also increases the risk to organisms, as oxygen levels become depleted in surface waters (p. 13). Another study found the toxicity to aquatic and other organisms was relatively low, but the oxygen-depletion effect of biodegradation was more serious (p. 245). Further, "Anaerobic biodegradation may also release relatively toxic byproducts such as acetaldehyde, ethanol, acetate, and methane (p. 245). "In Canada, Environment Canada reports that "in recent years, management practices at Canada’s major airports have improved with the installation of new ethylene glycol application and mitigation facilities or improvements to existing ones." Since 1994, federal airports must comply with the Glycol Guidelines of the Canadian Environmental Protection Act, monitoring and reporting on concentrations of glycols in surface water. Detailed mitigation plans include storage and handling issues (p. 27), spill response procedures, and measures taken to reduce volumes of fluid (p. 28).
In the EU classification of dangerous substances it is harmful (Xn) while more toxic substances are classified as toxic (T) or very toxic (T+). The U.S. Environmental Protection Agency generally puts substances which are lethal at more than 30 g to adults in Toxicity Class III.Ethylene glycol has a low vapor pressure; it does not evaporate readily at normal temperatures and therefore high concentrations in air or intoxication are unlikely to occur following inhalational exposures. There may be a slight risk of poisoning where mists or fogs are generated, although this rarely leads to poisoning as ethylene glycol causes irritation and coughing when breathed in, alerting victims to its presence. Ethylene glycol is not well absorbed through skin meaning poisoning following dermal exposure is also uncommon. Diagnosis
As many of the clinical signs and symptoms of ethylene glycol poisoning are nonspecific and occur in many poisonings the diagnosis is often difficult. It is most reliably diagnosed by the measurement of the blood ethylene glycol concentration. Ethylene glycol in biological fluids can be determined by gas chromatography. Many hospital laboratories do not have the ability to perform this blood test and in the absence of this test the diagnosis must be made based on the presentation of the person. In this situation a helpful test to diagnose poisoning is the measurement of the osmolal gap.