Antifreeze Poisoning in Humans – Signs and Symptoms

What is antifreeze?

Antifreeze is a also known as radiator fluid and is used to reduce the heat build up in car engines. Almost all antifreezes contain a compound called ethylene glycol, and some also contain methanol and/or isopropyl alcohol (isopropanol). Apart from antifreeze, ethylene glycol may also be found in brake fluid.

What is antifreeze poisoning?

Antifreeze poisoning is a fairly common occurrence with regards to poisoning – both accidental and intentional. Ingestion is the main path of entry into the body. Due to its sweet taste, antifreeze from leaking radiators or spilled bottles are quickly consumed by household pets (like dogs and cats). Infants who can access a poorly secured or open bottle of antifreeze may also be at risk of poisoning. Both these instances are accidental poisoning.

Antifreeze poisoning, like arsenic poisoning, is often implicated in deaths due to poisoning – either murder or suicide.  The sweet taste makes in fairly inconspicuous and if mixed with alcoholic drinks, it is easily missed. However, modern pathology and forensic science has made it easy for a case of antifreeze poisoning to be identified. New regulations in the United States have compelled antifreeze manufacturers to include bitter tasting additives to the final product.

Effects of Antifreeze Poisoning

The effects of antifreeze poisoning are not directly from ethylene glycol but rather as a result of the metabolites (breakdown products of ethylene glycol). Alcohol dehydrogenase (ADH), an enzyme in the liver and also found in the lining of the stomach, is responsible for the breakdown of ethylene glycol.

Ethylene glycol is sequentially metabolized into :

  • Glycoaldehyde
  • Glycolic acid (from glycoaldehyde)
  • Glycoxylic acid (from glycolic acid)
  • Oxalic acid (from glycoxylic acid)

Other additives like methanol and isopropanol are also broken down by ADH. Methanol is metabolized into formaldehyde and then into formic acid. Isopropanol is metabolized into acetone.

The effects of these metabolites affect multiple systems simultaneously. Some of the effects include :

  • Glycolic acid in the blood increases the pH of the blood (acidosis). This leads to hyperventilation as the blood tries expel carbon dioxide and increase the pH.
  • Oxalic acid may form oxalate crystals which bind with calcium in the kidney to form calcium-oxalate stones. These stones cause an obstruction for filtration and lead to renal insufficiency.
  • Formic acid damages the optic nerve leading to blindness.
  • Acetone depresses the activity of the central nervous system (CNS).

Signs and Symptoms of Antifreeze Poisoning

  • Nausea
  • Vomiting
  • Abdominal pain
  • Frequent and/or painful urination
  • Kidney pain and eventually kidney failure
  • Dizziness
  • Stupor similar to intoxication (drunkeness)
  • Shortness of breath (dyspnea)
  • Rapid breathing (tachypnea)
  • Diminished reflexes
  • Muscle spasms (cramps) and twitching
  • Partial or complete paralysis of certain body parts
  • Pancreatitis
  • Metabolic acidosis
  • Blindness
  • Seizures
  • Low levels of calcium (hypocalcemia), magnesium (hypomagnesemia) and a high level of potassium (hyperkalemia) in the blood, similar to fluoride poisoning.

Depending on the quantity of antifreeze consumed and whether prompt medical treatment is sought, antifreeze poisoning will lead to death.

Ask a Doctor Online Now!

Please note that any information or feedback on this website is not intended to replace a consultation with a health care professional and will not constitute a medical diagnosis. By using this website and the comment service you agree to abide by the comment terms and conditions as outlined on this page

  • Kym

    I found a spray bottle of rat poison hanging on door under my sink where you’d find my windex ( I didn’t buy it or put it there). Also the very same day I find antifreeze in my shed. I have lots of pets and never have that stuff around because I know if spilled my dogs would lick it up and I might never know what happened. Any way I’m going through a divorce that should have happened ten years ago. I’m an idiot who is paying for it now. But facts are the facts. More recent I have a jilted lover I kicked out two weeks ago. This is where it gets weird. Both guys I’ve learned are NARCISSIST two types though but I always felt they alike even though on outside it looks like opposite each other. Anyway lover I called him friend really he is pushy and he just moved in my new place last sept 2014. I sometimes felt they working together on something. My soon to be ex moves out of beach house and moves in with me but commutes 4 hours when he does work. He basically quits a good full time job so he says And now just works For himself and moves in with this guy here too and me who is trying to get lover/friend to move out cuz he refuses to get a job and help out. both him and my soon to be ex husband were without places and both content to stay at my place, too weird for me. Both cooked for me!!! I’ve been feeling sick for a few months now. I don’t know what to think. What do I do ? Please advise!! Soon to be ex husband has been hiding money for over a year now. He is in sales 47 years and is a master manipulator. Horrible at home but everyone just loves him who isn’t married to him. He is super greedy. We own a few properties together. I’ve learned since he moved in to my place just how crazy he is. No one will believe me. Well my kids might. I’m not keeping quiet about this stuff to them. Hubby n BF got chummy. Totally weird.

    I read where a guy killed his wife with antifreeze by mixing it into her sports drinks. She just got sicker and sicker. She was only in her late twenties.

    I need a swift kick in the butt. I read and hear this stuff but who wants to believe that this could be happening to them? That would mean action then and it’s hard to change all that up especially when you’re weak and broke.

    Please don’t say this is off topic. This is for the record. Thanks

  • Watch the Toes

    I know you posted this 2 months ago, but I hope you’re doing ok and read this.

    I think you really need to follow your intuition and get yourself and your kids as far away from both of these men as possible, and don’t eat any food they might have tampered with. Could you be over-reacting? Maybe. But if you’re not (and I have a feeling your aren’t), you could be saving your own life.

    If you don’t already have a escape plan, I really urge you to look into women’s shelters that you can go to if you don’t have friends/family or a place to stay. Start talking with your own lawyer – one who isn’t working for your husband (ex?) to get yourself squared away financially. But mostly, stay safe and don’t let either of these men know where you or the kids are going.

    Good luck, and I hope you find your way out of this.