Facts About Propylene Glycol and Ethylene Glycol (Antifreezing Agents)

Chemical Facts No. 13

Facts About Propylene Glycol and Ethylene Glycol (Antifreezing Agents)

What are ethylene glycol and propylene glycol?
(Pronounced eth'uh-leen gly'col and pro'puh-leen-gly'col)

Both ethylene glycol and propylene glycol are clear, colourless, slightly syrupy liquids at room temperature. Either compound may exist in air in the vapour form, although propylene glycol must be heated or briskly shaken to produce a vapour. Ethylene glycol is odourless but has a sweet taste. Propylene glycol is practically odourless and tasteless.

Both propylene glycol and ethylene glycol are used to make antifreeze and de-icing solutions for cars, airplanes, and boats; to make polyester compounds; and as solvents in the paint and plastics industries. Ethylene glycol is also an ingredient in photographic developing solutions, hydraulic brake fluids and in inks used in stamp pads, ballpoint pens, and print shops.

The Food and Drug Administration (FDA) has classified propylene glycol as an additive that is “generally recognized as safe” for use in food. It is used to absorb extra water and maintain moisture in certain medicines, cosmetics, or food products. It is a solvent for food colours and flavours.

Propylene glycol is also used to create artificial smoke or fog used in fire-fighting training and in theatrical productions.

What happens to ethylene glycol and propylene glycol when they enter the environment?

Neither compound is likely to exist in large amounts in air.
About half of the compounds that enter the air will break down in 24–50 hours.
Both compounds break down within several days to a week in water and soil.
How might I be exposed to ethylene glycol and propylene glycol?

You can be exposed to ethylene glycol when you use antifreeze, photographic developing solutions, coolants, and brake fluid. You can be exposed to propylene glycol by eating food products, using cosmetics, or taking medicine that contains it. If you work in an industry that uses ethylene glycol or propylene glycol, you could be exposed by breathing or touching these substances.


How can ethylene glycol and propylene glycol affect my health?

Eating or drinking very large amounts of ethylene glycol can result in death, while large amounts can result in nausea, convulsions, slurred speech, disorientation, and heart and kidney problems.

Female animals that ate large amounts of ethylene glycol had babies with birth defects, while male animals had reduced sperm counts. However, these effects were seen at very high levels and would not be expected in people exposed to lower levels at hazardous waste sites.

Ethylene glycol affects the body's chemistry by increasing the amount of acid, resulting in metabolic problems. Similar to ethylene glycol, propylene glycol increases the amount of acid in the body. However, larger amounts of propylene glycol are needed to cause this effect.

How likely are ethylene glycol and propylene glycol to cause cancer?

The Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), and the EPA have not classified ethylene glycol and propylene glycol for carcinogenicity. Studies with people who used ethylene glycol did not show carcinogenic effects. Animal studies also have not shown these chemicals to be carcinogens.

Is there a medical test to show whether I've been exposed to ethylene glycol and propylene glycol?

Tests are available to determine if you have been exposed to ethylene glycol. These tests are only used on people who are showing symptoms of ethylene glycol poisoning (but they could be used in other situations). The tests are most often used on people who have intentionally consumed, or who suspect they have consumed, large amounts of ethylene glycol.

Propylene glycol is generally considered to be a safe chemical, and is not routinely tested for, unless specific exposure, such as to a medicine or cosmetic, can be linked with symptoms. Since both propylene glycol and ethylene glycol break down very quickly in the body, they are very difficult to detect, even though symptoms may be present.

"Know the labels of what you eat and drink. Have a healthy life."...:>)

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