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From the sound of its name, it’s probably no surprise that propylene glycol is a synthetic chemical. (It’s actually the main ingredient in antifreeze!) And although its safety is questionable, it’s an incredibly common food additive that the FDA considers “Generally Recognized As Safe” (along with artificial food dyes).
Have you ever seen propylene glycol on a nutrition label and wondered, is it safe? Me too, and here’s what I found out!
What Is Propylene Glycol?
Propylene glycol is derived from petroleum and is a viscous colorless, odorless substance with a sweet taste. Food makers value it for its ability to keep a substance moist, maintain texture, and mix with almost anything (oil, alcohol, and water). Because of these properties and because it is generally recognized as safe, it has become a common food additive in processed or ready-made food items.
Processed food items containing propylene glycol are typically foods that require thickening, emulsifying, or stabilizing properties. These include:
- Salad dressing
- Liquid artificial flavoring
- Ice cream
- Artificial sweetener
- Icing
- Soft drinks
- Soups
- Puddings and desserts
- Sauces and dips
Propylene glycol is also often added to body care products, cosmetics, and medications.
Is Propylene Glycol Safe?
The safety of propylene glycol depends on the dose and individual susceptibility. So it is possible that if you are 100% healthy, exposure to small amounts once in a blue moon might be okay.
Unfortunately, when people consume the processed foods listed above, they usually consume a sizable amount on a regular basis, which is definitely not healthy.
Physiological Side Effects of Propylene Glycol
Consumption of propylene glycol has many known effects … here are the biggies.
Acidifies the Blood
Propylene glycol absorbs very quickly in the small intestine with peak levels detected in the blood about an hour after ingestion. It is also quickly eliminated (almost 50% of what is consumed is left after 4 hours).
About 55% of this is metabolized into lactic and pyruvic acids, while the remaining is eliminated by the kidneys (source).
These lactic and pyruvic acids make the blood more acidic. At low doses, the kidneys can immediately re-balance the blood alkalinity. But higher doses of propylene glycol can acidify the blood, injure the kidneys, and cause toxicity. This is why consistent consumption in large amounts is a bad idea.
In a large enough amount it can acidify the blood to the point that it requires emergency medical care. There are a few case reports, including in the New England Journal of Medicine, when patients injected with psychiatric drugs containing propylene glycol were shown to quickly develop acidosis that can cause a coma and kidney failure. Propylene glycol toxicity can also result in similar symptoms to sepsis or severe inflammatory response syndrome (source).
While it is possible to achieve this dosage level by ingesting it, this reaction is typically only reported when it is administered at a very high dose of over ~2 grams (source).
Contributes to Leaky Cells and Leaky Gut
Like soap, propylene glycol is a surfactant, which means it can break the barrier between fat and water. Our cell membranes are made with thin layers of fat molecules, which can be easily disrupted by surfactants like propylene glycol.
Pharmaceutical companies capitalize on this property by mixing or chemically binding drug molecules to propylene glycol to increase the drug absorption rate (source). This is the case for both drugs that are taken orally and topically.
Cells exposed to propylene glycol become more permeable to other molecules (source). (This is why the safety of e-cigarettes containing propylene glycol together with nicotine and cancer-causing substances is very questionable).
Currently, there is no study that directly tests whether propylene glycol causes leaky gut and the inflammatory health problems caused by the leaky gut. However, in a test tube study, propylene glycol even at low concentration destroyed some gut cells (source).
Those who struggle with leaky gut, autoimmune diseases, or digestive issues, may want to consider avoiding propylene glycol for these reasons.
Increases Risks of Childhood Allergies & Asthma
And if that’s not enough, it may affect our kids as well.
As a volatile organic compound (VOC) emitted from building materials, furniture, paint, carpet and the like, propylene glycol can aggravate the immune system. In a study evaluating the effects of propylene glycol and glycol ether vapors in the air on preschool children’s health, the authors found that the presence of such chemicals in a child’s bedroom air is associated with:
- 1.5-fold increased risks of asthma
- 2.8-fold increased risks of allergic rhinitis (hay fever)
- 1.6-fold increased risks of eczema (source)
A good air purifier can help remove airborne chemicals and is a great idea in any sleeping space.
Irritates the Skin
Propylene glycol has been reported as a skin irritant that can cause dermatitis, an eczema-like rash (source). When added to skin, body care, and cosmetic products, it can really aggravate skin problems. (Ironically, it is often an ingredient in topical medications to treat these skin conditions! How does that make sense?!)
When to Avoid Propylene Glycol
Some people are more sensitive to the side effects of propylene glycol than others. Those who are generally cautioned to avoid it are:
- People with liver or kidney problems, because the liver and kidneys are responsible for eliminating propylene glycol and its byproducts
- Pregnant women, babies, and infants as they have reduced ability to handle these types of ingredients (source)
- People with inflammatory health problems because it can irritate cells and cause leaky gut
- People with digestive problems because it will further irritate the gut cells
Fortunately, it is possible to avoid and/or reduce your exposure to as much as possible.
How to Avoid Propylene Glycol
Unfortunately, this additive is in a lot of common products, so it takes some diligence to avoid it! A few tips:
Avoid Processed Foods
The best way to avoid foods dangerous ingredients such as propylene glycol is to eat home-cooked meals the majority of the time. Fake ingredients are not necessary to make food delicious. It is possible to replace the effects of these types of additives with other, natural ingredients, such as gluten-free starch or gelatin as a thickener or stabilizer.
Read Labels and Buy from Trustworthy Brands
Always check the labels of your food ingredients and other household products for propylene glycol and its synonym, propane-1,2-diol.
I like to use brands that never put such dangerous ingredients in their products, like Primal Kitchen for mayonnaise for sauces and dressings.
Check Your Skincare, Body Care, and Home Care Products
Propylene glycol is everywhere in conventional products that people put on their skin every single day. Not only that, these skin products often contain other toxic chemicals that will be more readily absorbed through your skin because it makes your skin more permeable.
Instead, rely on organic products or make your own beauty products instead.
Use Air and Water Purifiers
Despite best efforts to avoid propylene glycol in foods and other products, exposure is still possible in the air or water in your home. Good ventilation (including opening windows to air the house out), a good air purifier in sleeping rooms, and a water filter for drinking and shower water are important.
We’ve tried several filters over the years and I’ve given my review of the best air and water filter options we’ve found.
Have you ever had a reaction to propylene glycol? Which food additives do you say “no” to for your family? Please share with me in the comments!
It’s in most popular brands of mouthwash. My dentist recommended fluoride mouthwash, but it’s difficult to one without propylene glycol.
You might read up on fluoride too then.
About six years ago, when I became pregnant with my first child, I developed many allergies to chemicals. This is one chemical that my body has a severe reaction to, and the allergist I’ve worked with rates it as something I absolutely cannot have interaction with. The size of the hives/blisters that it gives my skin is so disturbing. And they take at least three weeks to go away. Back then I thought I knew about what was wfpb, and healthy skincare. Turns out, many food, household, and skincare items were given away I’ve been very careful since then to make sure read labels. And you’re right, most of the time it is the main ingredient to any topical medicine. It’s such a bummer. My dermatologist and allergist are at a loss of currently being able to actually find any topical treatment for an unrelated reoccurring rash. And this is not the first time.
Hi Katie, can you do an article on what supplements you and your family take? I was trying to comment on your teeth whitening article but it looked like it was closed from further comments. You mentioned that your husband’s teeth color improved with his diet and supplements so I wondered what and how many kinds he and anyone else in the family takes.
Also , could you post more pictures of your teeth ? I’m curious how white they are today compared to the ones you posted in your other article.
Thanks!
Yes! Working on updating my posts on that and will share a tooth selfie on IG and FB soon 🙂
Excellent article! This additive has been popping out at me on everything I touch. I’ve dropped the items like hot potatos!
Thank you for being a source of information that helps me make wise decisions concerning my health and the health of my family.
It is also a major ingredient in sun block lotions. I am so allergic to it when exposed to the sun that until I knew what it was that made my skin burn like fire with a blistered rash, I had to cover myself head to toe. I now use only aveeno lotions as it does not have pg.
I’ve seen it added to processed meats, such as bacon I would like to buy at the farmer’s market. Which is very frustrating, because here’s this great pasture raised meat I’d like to eat and then the butcher adds all these weird ingredients to it. When I mention it to the farmers, I hear over and over again that they are frustrated too but it is so hard to find a good butcher because of regulations.
I tested positive in allergy testing to ALL glycols after having anaphylaxis to a salad dressing containing propylene glycol. I’ve talked to chemists all over the US – glycols are prevalent in inactive ingredients in many, many medications. They are in food dyes, and shampoo, lotions, makeup – virtually every aspect of our way of life. I’ve learned to only eat what I prepare myself, and to check everything that touches my body.
My daughter has the exact same story. After she experienced anaphylaxis and ended up being taken to an emergency room by ambulance, she was tested for allergies. The highest allergent was propylene glycol. Since then we’ve been keeping track of ingredients to foods she’s had reactions to and it seems that any glycol, glycerin, or poly-alcohol organic compound can cause her to have a reaction. What’s worse, she reacts to aerosols with glycols, so she’s learned to avoid busy public bathrooms (perfumes, e-cigs, etc.). PG anaphalaxis by inhalation appears to be rare and isn’t well studied yet. We’re waiting for it to become better recognized. The very good news is her diet is extremely healthy, not by choice, and she’s likely to avoid the diabetic and cholesterol issues that run in both sides of the family.
Were you aware that Propylene Glycol is the main ingredient in KY Jelly? I use PG diluted in water as a retardent to the drying time of artist-quality acrylic paint, but if I don’t have any left I happily sub in KY Jelly. I don’t eat any processed food, so not too much of a problem as far as diet goes but I’ll keep my eyes open from now on.
Ugh! That’s like hearing Coke is a great paint remover!
Oh, did I ever get a case of dermatitis from ecig liquid!
Couldn’t figure it out for the longest time and the doctors didn’t have a clue. I took 2 back to back courses of oral anti-fungal and antibiotics, plus skin cream…didn’t touch it.
I finally figured it out and switched to a veg glycerin base, and it began to clear. This process took close to 2 years!
I don’t generally buy any processed foods, make my own cleaning supplies and keep it organic as best I can.
I. Had. No. Idea!
Wow, what a well written article! Yes, this is one of the things I see and wonder what it is. Fortunately I only eat whole foods and scrutinize any skin or even cleaning products. I don’t use anything with stuff I can’t visualize. But it’s pretty messed up to know they are happily putting this in our food supply. Especially the part about it dissolving the fat between our cells in some unnatural way. I’m glad for this article so that I understand better what it is and to stay alert.