If you think your natural deodorant and organic ice cream doesn’t contain this, then you better double check that ingredient label.
Oh wait, not even that is required to tell you.
You see, depending on the amount and how it’s used, this synthetic compound can be legally categorized within the “natural flavor” and “artificial flavor” catch-all terms in the United States, according to 21 CFR 101.22 (a)(1) and (3). (1).
Unless a company has specifically gone on record to say they don’t use it, you shouldn’t make assumptions of its absence. Not even with the organic foods and natural skin and hair care products.
What is propylene glycol?
At room temperature it take the form of a clear syrup, but it can also be vaporized and is done so for e-cigarettes and in artificial smoke machines. What propylene glycol is most commonly used for is as an antifreeze, solvent, and to promote moisture by the absorption of water. The applications are far reaching, ranging from the common de-icing spray used on commercial aircraft, to being a stabilizing agent in topical, oral, and intravenous medications.
Since the FDA categorizes it as “generally recognized as safe” (GRAS), it’s commonly used as a thickener and stabilizer in things like beer and salad dressings, and for being a solvent and carrier in added flavorings and food coloring. Ice cream, sweeteners, and sodas are foods which frequently contain propylene glycol.
If it is disclosed on an ingredient label, other names for it may be used such as propane-1,2-diol, 1,2-Propanediol, 1,2-Dihydroxypropane, Methylethylene glycol, and Methyl ethyl glycol (MEG).
Why should you avoid it? Even though the legal amounts we’re exposed to are believed to be safe, here are 10 good reasons why its prevalence should concern you.
1. Made from a known mutagen, suspected carcinogen
It’s made from propylene oxide, a substance that has “been found to be a direct-acting mutagen” which means it can mutate DNA. (2)
All cancers are the result of DNA mutations.
If and when extensive studies are done to prove the amount of mutations can increase cancer rates, then a mutagen also gets classified as a carcinogen.
Now to be clear, propylene oxide should not be in pure propylene glycol, but how many things in life are truly 100% pure?
The fact that China and neighboring countries are large producers of it probably doesn’t add to your confidence in its purity!
Cosmetic and food grade are not required to be 100% propylene glycol. Purity of 99.8% and above is permissible.
The other 0.2% of miscellaneous may not seem like much, until you hear how much is being used in food.
2. Staggering amounts are used in your food
The FDA regulates how much can be used, by following the limits laid out in Title 21.
So how much are we talking about here?
The following maximum amounts of propylene glycol are what the “current good manufacturing practices” are for your foods and drinks which use it (5):
- 97% of seasonings and flavorings
- 24% of confections and frostings
- 5% of alcoholic beverages
- 5% for nuts and products made from them
- 5% of frozen dairy products
- 2% for all other foods
Does wine contain propylene glycol? There’s no law excluding its use, but it’s presence in pinot noir or chardonnay seems unlikely. You’re more likely to find it in pseudo versions of the drink, like wine coolers.
When PG makes up to 97% of an ingredient, you understand why that 0.2% of other chemicals suddenly becomes a big amount over time!
3. How much the US allows is shocking
Israel lowered the limit several years ago. Now the maximum amount they consider to be safe and/or acceptable in beverages is just 1 gram per liter.
To put that in perspective, 1 liter of water weighs 1 kilogram. If only 1 gram is allowed in the liter, that means it’s only a 0.1% concentration. (6)
Most non-creamy liquid beverages – whether soda, juice or vodka – will be the same or very close to the weight of water.
The European Union uses for it the food additive E number 1520 (E1520). To legally sell edible items containing propylene glycol, manufacturers must abide by much stricter limits than the US. When used as a carrier/solvent for emulsifiers, colors, nutrients, antioxidants, and enzymes:
“…a maximum allowed level of 1 g/kg (0.1 percent), in the food stuff”
Beverages are a similar 1 gram per liter. In flavorings, it’s a max of “3 g/kg, from all sources in foodstuffs as consumed or as reconstituted according to the instructions of the manufacturer.”
But wait, it gets even more strict. Those limits are for E 1520 used by itself or in combination with others:
- E 1505 (triethyl citrate)
- E 1517 (glyceryl diacetate)
- E 1518 (glyceryl triacetate)
So those three and E 1520 combined cannot exceed the 1 g/kg and 3 g/kg limits. That means even less E 1520 must be used if some of those others are part of the ingredients. (7)
4. Used in natural products and possibly organic foods
Watch out for deceptive labeling. In the United States, here are the legal definitions:
- “100% Organic” – The only non-deceptive label. It means exactly what you think.
- “Organic” – That means 95% or more is organic. The other 5% doesn’t need to be.
- “Made With Organic Ingredients” – That requires 70% or more organic ingredients.
- “Natural” – Not regulated, can mean almost anything.
- “All-natural” – Not regulated, can mean almost anything.
Most items you buy are not labeled 100% organic. Things like cereals, crackers, chips, dressings, and sauces are more likely to be simply labeled “organic.” So what can the other 5% include?
If you looked at National Organic Program in Title 7, you will find “The National List of Allowed and Prohibited Substances.” You won’t this specific substance anywhere in the prohibited list, nor will you find it in the allowed list. (8)
The language of the “allowed” section starts out with this:
205.606 Nonorganically produced agricultural products allowed as ingredients in or on processed products labeled as “organic.
Only the following nonorganically produced agricultural products may be used as ingredients in or on processed products labeled as “organic,” only in accordance with any restrictions specified in this section, and only when the product is not commercially available in organic form.
Then they list a few dozen things which are allowed. Some clearly would exclude propylene glycol in food coloring:
(d) Colors derived from agricultural products—Must not be produced using synthetic solvents and carrier systems or any artificial preservative.
Since it’s a synthetic carrier, it wouldn’t be allowed. But then you go up two letters above that:
(b) Celery powder.
That’s all it says! Since propylene glycol “is not commercially available in organic form” could it be used for celery powder? The answer is murky.
Now it’s unlikely anyone would even need to use that substance for celery powder, but how about this next example:
(i) Gelatin (CAS # 9000-70-8).
That number just corresponds to the CAS identifier for gelatin from bovine skin. There are plenty of other things which are poorly defined, such as “starches” and “whey protein concentrate.” Starch is in bread and pastries. Whey is used as a protein boost in many snack bars and bottled drinks.
In short, there seems to be wiggle room here where a manufacturer might be able to use it, yet still label their food as being organic.
Even if it’s marked as natural, propylene glycol in lotion, deodorant, toothpaste, and hair care is 100% allowed. It’s the Wild West, because the word “natural” is not regulated in the US like it is in many other countries.
In the EU and UK, it’s allowed to be used as a veterinary medicine on animals which will eventually be eaten (Annex II; Regulation amending Annex of Regulation 2377/90: Reg. 270/97). For the EU guidelines on organic meat sources (livestock) the word isn’t even found in the protocol for veterinary treatments. It’s not allowed but it’s not disallowed, either. (9)
5. Kidney, liver, and CNS side effects
A couple years ago, the European Medicines Agency published an assessment report titled “Propylene glycol in medicinal products for children.” In it they discuss the pros and cons, but mostly the latter! (10)
They report that in adults, 45% of propylene glycol is eliminated by the kidneys and 55% by the liver, where it gets converted to lactic acid, pyruvic acid, or acetone. That’s why they say:
“Patients with impaired liver and/or kidney function are at an increased risk for developing propylene glycol toxicity.”
The news is even worse for your toddlers and babies. The report says that due to the young child’s liver and kidneys not being developed, they are at increased risk for poisoning from accumulation, since it can’t be broken down fast enough by the body.
Overdosing on propylene glycol is listed as being associated with the following side effects:
- Depression of the central nervous system (CNS)
- Limited metabolic capacity
- Potential accumulation in young children
Is propylene glycol safe to consume? Consider that on page 18 of the report, the first bullet point of the agency’s overall conclusion states:
“no recommendation on a safe dose for propylene glycol can be made based on the current available data”
They’re not saying it’s unsafe in low dosages, but they are saying there’s not data to conclude the opposite – that it is safe for younger children. That’s an unknown according to this report.
For you – the adult – consider that in the United States, approximately 1 out of 7 people have chronic kidney disease. Diabetics and those with high blood pressure are at increased risk of developing this during their life. That’s a large portion of the population who may be consuming something that makes these vital organs work harder than they need to. (11)
6. Manufacturer boasts about “low” toxicity
To be clear, this is not in reference to food grade propylene glycol. Rather, it’s about the industrial grade but that’s still 99.5% pure.
Dow Chemical, one of the leading manufacturers, lists 6 bullet points as to why their industrial grade version “is an excellent choice” for use in deicing aircraft solutions. Two of those selling points are (12):
- “Low toxicity”
- “Low corrosive nature to metals”
No when you hear “industrial grade” you may assume it’s a low quality product. That’s definitely not the case with Dow. They produce a much higher quality version than many Chinese and Asian manufacturers.
The technical data sheet for Dow’s industrial version lists it as having 99.5% purity.
The minimum of 99.5% is very close to the 99.8% purity required for food grade. Do statements about being “low” toxic and corrosive make you feel good, considering that it’s only 0.3% less pure?
7. Can you be allergic to propylene glycol?
When you have an adverse reaction to a skin care product, you may assume it’s caused by one of the active ingredients used. What you may be experiencing is allergic contact dermatitis from PG, which is a well-documented side effect in medical literature, yet it often goes unrecognized as being the root cause of irritation since people do not expect it. (13)
The worst part is that the antihistamines you take to fight your allergies may actually be making them worse!
The University of Massachusetts recently published a paper titled “Excipients in Oral Antihistamines Can Perpetuate Allergic Contact Dermatitis.” In it they talk about teens who had patch testing to confirm their allergy to propylene glycol. Their “dermatitis improved dramatically after cessation of oral antihistamines” which had contained this chemical. (14)
Another piece of research analyzed numerous oral antihistamines for sale and found the following (15):
- Over 25% of allergy medicines contain propylene glycol, azo dyes, and sorbitans.
- 100% of liquid syrups and gelcaps tested were said to contain at least 1 of the 10 allergen families.
“Ingestion of antihistamines could precipitate a systemic contact dermatitis in a patient sensitized to an allergen present as an excipient in the medicine.”
If their presence in those medicines can cause an allergy attack, then one would think the same is possible when ingesting food and beverages containing propylene glycol. If a couple teaspoons of cold and cough syrup can cause an attack, then imagine what drinking cans of soda, beer, and dairy products all day long might be doing to you.
8. Believed to cause or worsen asthma
Even as far back as two or three decades ago, the scientific community was ringing the alarm bell about this issue. Despite the evidence, it remains ignored.
Probably because addressing it would lead to liability issues for the manufacturers of foods, medicines, disinfectant sprays, perfumes, and much more.
The French-language Thérapie is a respected peer-reviewed medical journal. Twenty years ago they published a piece expressing grave concerns about this chemical. Translated from French to English, its title was “Cough or asthma crisis induced by propylene glycol.” (16)
Aerosol forms of it are prevalent, as they are used in everything from common household cleaning products to theatrical smoke machines. Not to mention, air pollution from exterior uses like de-icing treatments.
Why have childhood asthma rates soared during the past few decades? Perhaps this chemical is one of the culprits.
There was a study published involving 400 children; 198 with asthma and allergies, 202 who were healthy.
Their bedroom air levels of propylene glycol and glycol ethers were measured. Even for those kids who were in the mid-range of exposure – between the 75th and 25th percentiles – it was found that there was:
- 1.5-fold higher rate of asthma
- 1.6-fold for eczema
- 2.8-fold higher rate of rhinitis
Those increases were even after accounting for other variables like gender, other allergens present, genetic history, and so forth.
If you think chemicals in general are to blame, they reported there were “no similar associations” found for other types of VOCs. (17)
One of Superfoodly’s own (Michael) has firsthand experience of propylene glycol vapor asthma attacks.
That’s him in the black t-shirt with Gene Simmons and Paul Stanley. This faux-backstage encounter was shot many times over. With smoke machines running full blast all day, this triggers very bad asthma in him. Now for that particular instance, he hid his inability to breath (Dr. Pepper commercial during Superbowl is worth the ka-ching). Though he is shocked that OSHA law and regulations still haven’t addressed exposure to artificial smoke machines which use this chemical in a vapor form.
9. Might increase your skin’s absorption of toxins
Why do you think nicotine patches and transdermal pain meds are such effective delivery methods?
Your skin is a sponge. That’s why it’s so important to use real organic and natural skin care products when possible. Because ultimately, the chemicals you put on your skin can be partly absorbed and end up inside of you.
The potential dangers of propylene glycol in skin care products may be greater than just rash, eczema, and dermatitis. There’s not much research on this topic, but some studies have found that its presence appears to increase the transdermal absorption rate of some other compounds it is mixed with. (18) (19)
That may be good for you when it comes to the absorption of topical antioxidants. More likely though, your face creams and sunscreens contain harmful things which you do not want higher absorption of!
10. Is propylene glycol safe while pregnant?
Pregnancy studies using mice and rats suggest that even at high dosages, PG does not cause birth defects or abnormal birth weight. That’s good news but it does not provide the full picture of what adverse reactions might be happening in a developing baby. (20) (21)
In the study mentioned above about the 400 children, they also noted that in the cases there was a “1.8-fold greater likelihood of IgE-sensitization.” In other words, an increase in allergic sensitization.
If that is happening in young children, then what about those still in the womb who might be exposed to it? Might its presence in the mother’s blood stream lead to a higher rate of IgE-sensitization?
We all know allergy rates are on the rise and out of control. Anything that has a remote possibility of causing IgE-sensitization seems like it’s not worth the gamble. Avoiding propylene glycol during breastfeeding and pregnancy entirely would be impossible, but reducing consumption in your diet, with your cleaning products, and other sources seems like a wise idea.
3 tips for going propylene glycol free
You can’t avoid always avoid it, but there are simple changes you can make in your life to reduce how much you are exposed to on a daily basis.
1. Less processed food = less likely to contain it
Can you buy it at a gas station? Is the expiration date for that “fresh” baked pastry many months out?
Things like that should clue you in.
Many of the most common foods with propylene glycol in them are also the most processed. You will find it in things like ice cream, soda, salad dressings, baking mixes, frosting, candies, frosting, and premade teas and coffee drinks.
The fewer ingredients there are, the less likely it’s inside.
But even when the ingredient list is not that long, it could still be there. Some have asked us for brands of ice cream that contain propylene glycol, but answering that question thoroughly is impossible due to our country’s labeling laws. It could be used as part of “artificial flavors” or “natural flavors.” Even with organic ice cream brands, it could be within the 5% of non-organic ingredients, such as whey protein concentrate (discussed above).
Now if the ice cream contains an artificial food coloring, that should be a major red flag since PG is often used as a dye carrier.
For your own baking at home, check out our review of organic food coloring recipes and ready-to-use dyes.
2. Scrutinize your shampoo, soap, skin care and more
Everything from mouth wash to baby wipes may contain this chemical. It’s prevalent throughout personal hygiene products. Even many of the so-called “natural” brands might be using it.
If it’s list on the label, a synonym may be used for it like propane-1,2-diol, 1,2-Propanediol, and 1,2-Dihydroxypropane. Listerine contains it, but at least they’re straightforward and call it by the most common name.
One of the brands that has committed to not using propylene glycol is Tom’s of Maine. Because we also recommend avoiding titanium dioxide, we buy this specific version on Amazon of their fluoride-free toothpaste, which also leaves out the titanium dioxide.
3. Look out for laundry detergent
This may be one of the most important. Why? Because your clothes and bedding are in constant contact with your skin and on top of that, vapors are created when you wash and dry them. It’s a double-whammy.
Even the Tide Free & Gentle line has it in the ingredients. To get a detergent that doesn’t have it, you probably will need to go with a non-traditional brand.
But even products you find at Whole Foods might contain it. Seventh Generation fabric softener has dipropylene glycol.
Laundry detergents that do not contain propylene glycol include those from Mrs. Meyer’s Clean Day. Their website states:
“Our products do not contain ammonia, chlorine, glycol solvents, parabens, phthalates, formaldehyde, artificial colorants, phosphates or petroleum distillates.”
PG is a glycol solvent, so that means their detergent doesn’t use it. You can get Mrs. Meyers on Amazon.