[1][4] The diagnosis may be suspected when calcium oxalate crystals are seen in the urine or when acidosis or an increased osmol gap is present in the blood.

[1] Diagnosis may be confirmed by measuring ethylene glycol levels in the blood; however, many hospitals do not have the ability to perform this test.

[5] Antifreeze products sometimes have a substance to make them bitter added to discourage drinking by children or animals but this has not been found to be effective.

[9] Other sources of ethylene glycol include windshield deicing agents, brake fluid, motor oil, developing solutions for hobby photographers, wood stains, solvents, and paints.

[9] The most significant source of ethylene glycol is from aircraft de-icing and anti-icing operations, where it is released onto land and eventually to waterways near airports experiencing cold winter climates.

[12] In 2006, approximately 1540 kilotonnes of ethylene glycol were manufactured in Canada by three companies in Alberta, with most of the production destined for export.

[7] The central nervous system is affected early in the course of poisoning as the result of a direct action of ethylene glycol.

A toxic dose requiring medical treatment varies but is considered more than 0.1 mL per kg body weight (mL/kg) of pure substance.

Poison control centers often use more than a lick or taste in a child or more than a mouthful in an adult as a dose requiring hospital assessment.

[citation needed] 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.

However, acidosis has a large number of differential diagnoses, including poisoning from methanol, salicylates, iron, isoniazid, paracetamol, theophylline, or from conditions such as uremia or diabetic and alcoholic ketoacidosis.

Following ingestion of antifreeze products containing ethylene glycol and fluorescein, a Wood's lamp may reveal fluorescence of a person's mouth area, clothing, vomitus, or urine which can help to diagnose poisoning.

[30][31] Antifreeze products for automotive use containing propylene glycol in place of ethylene glycol are available, and are generally considered safer to use, as it possesses an unpleasant taste in contrast to the perceived "sweet" taste of toxic ethylene glycol-based coolants, and produces only lactic acid in an animal's body, as their muscles do when exercised.

[36] Following decontamination and the institution of supportive measures, the next priority is inhibition of further ethylene glycol metabolism using antidotes.

Ethanol acts by competing with ethylene glycol for alcohol dehydrogenase (ADH), the first enzyme in the degradation pathway.

Because ethanol has nearly 100 times more affinity for ADH, it blocks the breakdown of ethylene glycol into glycolaldehyde, thus preventing further degradation to oxalic acid and the associated nephrotoxic effects.

Pharmaceutical grade ethanol is usually given intravenously as a 5 or 10% solution in 5% dextrose, but it is also sometimes given orally in the form of a strong spirit such as whisky, vodka, or gin.

[7] Fomepizole is a potent inhibitor of alcohol dehydrogenase; similar to ethanol, it acts to block the formation of the toxic metabolites.

[45] Alternatively, people presenting late with signs and symptoms of coma, hyperkalemia, seizures, or severe acidosis have a poor prognosis.

[17] People who develop severe central nervous system manifestations or stroke who survive may have long term neurologic dysfunction; in some cases they may recover, although convalescence may be prolonged.

[55][56][57] Many cases of poisoning are the result of using ethylene glycol as a cheap substitute for alcohol or intentional ingestions in suicide attempts.

[64][68][69] Specifically, Mullins finds that bittering of antifreeze does not reduce reported cases of poisoning of preschoolers in the US state of Oregon.

[68] Similarly, White found that adding bittering agents did not decrease the frequency or severity of antifreeze poisonings in children under the age of 5.

[69] Additionally, another study by White found that suicidal persons are not deterred by the bittered taste of antifreeze in their attempts to kill themselves.

[64] These studies did not focus on poisoning of domestic pets or livestock, for example, or inadvertent exposure to bittered antifreeze among a large population (of non-preschool age children).

[70] An online veterinary manual provides information on lethal doses of ethylene glycol for chicken, cattle, as well as cats and dogs, adding that younger animals may be more susceptible.

[71] Ethylene glycol was once thought innocuous; in 1931 it was suggested as being suitable for use as a vehicle or solvent for injectable pharmaceutical preparations.

[16] Ethylene glycol involved in aircraft de-icing and anti-icing operations is released onto land and eventually to waterways.

[75] Detailed mitigation plans include storage and handling issues (p. 27), spill response procedures, and measures taken to reduce volumes of fluid (p. 28).

[12] In the U.S., airports are required to obtain stormwater discharge permits and ensure that wastes from deicing operations are properly collected and treated.