Odds are you wouldn’t eat something that includes the same ingredient – propylene glycol – found in antifreeze, paint, and plastics. Yet this chemical compound is mixed into thousands of grocery items as a food additive, as well as certain medicines and cosmetics, — even the food our pets eat.
Propylene glycol (PG) is a petroleum-based, colorless, creamy liquid with a faintly sweet taste; it’s used as a solvent to absorb extra water or maintain moisture in certain medicines, cosmetics, and food products. It has been the focus of controversy ever since its introduction in the 1960s. You can find it in Valium, Dunkin Donuts flavored ice tea, Windex, Right Guard Deodorant, Glade Aerosol, Liquid Nails, Jergens Skin Moisturizer, Cover Girl mascara, Clearasil, Lysol antibacterial hand wash, Noxzema, Colgate toothpaste, and Nilodor Deodorizing Ferret Shampoo.
“Some people claim it to be utterly harmless while others speak as if it’s responsible for devastating diseases like cancer,” says Dr. Josh Axe, a certified doctor of natural medicine, chiropractor, and clinical nutritionist.
The Federal Drug Administration (FDA) seems to hedge also. The FDA classifies propylene glycol as an additive that is “generally recognized as safe” for use in food – not exactly a ringing endorsement.
According to Scholar Chemistry’s (now Ward’s Chemistry) material safety data sheet, problems associated with liquid GP include irritation and sensitivity to the eyes, skin, and mucous membranes.
There are also problems with its vapor form, which it produces when heated or briskly shaken. GP was first synthesized as a vapor specifically used as an airborne antibacterial. It was pumped through vents in hospitals, and used in asthma inhalers for the purpose of inhibiting the spread of bacteria. It then began showing up to create artificial smoke or fog used in fire-fighting training and in theatrical productions.
A number of studies have been published on the potential health impact of exposure to theatrical fog. The Mount Sinai School of Medicine and the National Institute for Occupational Safety and Health each prepared studies for the League of American Theatres and Producers focusing on the effects on actors and performers in Broadway musicals. The conclusion was that there was irritation of mucous membranes such as the eyes and the respiratory tract associated with extended peak exposure to theatrical fog.
In 2005, a study published in the American Journal of Industrial Medicine determined that cumulative exposure to mineral oil and glycol-based fogs were associated with acute and chronic adverse effects on respiratory health.
E-cigarettes Produce Real Cough
An argument can be made that electronic cigarettes are a whole lot better for your health than the real deal — until you look a little closer. All e-cigarettes operate on a simple principle: A liquid is converted to a vapor through the process of heating it. A battery sends an electric current to a wad of liquid-soaked wicking material that is tightly wrapped with a metal coil that heats up like a burner on an electric stove. Once the coil becomes hot enough, the liquid that is in contact with the coil also begins to heat up, eventually to the point the liquid becomes converted to a vapor, which is then inhaled. The liquid that turns to vapor is propylene glycol, which contributes to taste and “smoothness” of the smoke.
A 2014 National Center for Biotechnology Information (NCBI) report concludes that based on 44 articles, the propylene glycol used in e-cigarettes “produce mouth and throat irritation and dry cough.”
Additional Side Effects Of Propylene Glycol
Despite the FDA’s milquetoast evaluation of propylene glycol, there are several other health concerns, including:
- Infants And Pregnant Women — Propylene glycol enters the body as an alcohol and metabolizes in the body’s enzyme pathways. These pathways do not mature in humans until 12 to 30 months of age. Infants and children below the age of 4 years, pregnant women, and those with kidney dysfunction or in renal failure are not able to eliminate propylene glycol in the body. Even the FDA concedes this inability to process and eliminate this product causes potential adverse reactions in infants and pregnant women as well as those with kidney problems. The World Health Organization (WHO) has specified that the acceptable daily intake of propylene glycol as a food additive is no more than 25 mg per kilogram of weight per 24 hours.
- Potentially Toxic To The Liver And Kidneys – Propylene glycol is used in many IV medications, including Lorazepam, an anxiety-reducing and seizure treatment medication. Like Xanax, Lorazepam belongs in the benzodiazepines family of drugs, known for their widespread abuse. This drug is often administered to patients with extensive burns as sedation during the healing process or to psychiatric patients. When given Lorazepam for an extended period of time in large doses, clinicians have discovered possible kidney issues in the form of increased creatinine levels in the blood. Generally, creatinine (a product of muscle breakdown and growth) remains in consistent levels in the bloodstream, according to Axe. “Excess creatinine is a sign that the kidney is unable to process compounds at a normal rate.” A 2007 study from the University of Connecticut assessed the treatment of propylene glycol toxicity and also noted it can be dangerous for those with liver problems.
- PG Allergies – It’s not completely understood why some people develop a sensitivity to PG. Dr. John L. Meisenheimer, a board certified dermatologist and skin-care expert, says that once a patient becomes allergic, the immune system always remembers the sensitivity. He recommends only using products approved by your dermatologist or allergist, and to be careful about physical contact with others who might use products containing PG.
- Cardiovascular – There have been some alarming cases linking PG exposure with heart diseas e. “One such patient was an 8-month-old who suffered a heart attack after four doses of topical medication to treat a burn,” says Axe.
- Neurological Symptoms – The Centers for Disease Control and Prevention (CDC) toxicity profile negatively assessed propylene glycol in the area of neurological symptoms, according to Axe. When taken orally and tested by patch test to find the amount of the chemical compond still in their system, a number of people were found to have varying degrees of neurological issues, including stupor, convulsions, and other unspecified “severe mental symptoms.”
- Harmful To Pets – GP is a common pet food additive. The FDA says dogs can handle small doses. However, according to Dr. Karen Becker, an integrative wellness veterinarian, propylene glycol can be toxic to dogs at certain levels. “We just don’t know with specificity what those levels are,” says Becker. The bigger GP issue is with cats. Just a small amount, says Becker, can cause Heinz body hemolytic anemia, a condition in which red blood cells are destroyed. This is why cats die when they lap up the sweet taste of PG in antifreeze. While the FDA has banned PG in cat food, it stills shows up. Just last year commercially available cat treats were recalled after low levels of propylene glycol were found in the product.
A Catalyst For More Damage
Axe says the most concerning part of constant propylene glycol exposure is the way it may provide other chemicals a free pass into your bloodstream.
“Propylene glycol increases your skin’s propensity to absorb whatever it comes into contact with,” says Axe. “Considering the large amount of dangerous chemicals we encounter on a regular basis, this may be of even more danger than the compound itself.”
How To Avoid Propylene Glycol
There are enough red flags to avoid PG all together in order to protect your general health, hormone balance, and overall chemical exposure.
A 2013 NCBI report concurs, advising to avoid propylene glycol as a food additive. The simplest way to do this is by reading labels. Just keep in mind that propylene glycol is also listed as propane-1,2-diol.
The problem is that a great number of cosmetics include propylene glycol, but in the U.S., cosmetics aren’t very well-regulated and needn’t list ingredients. Axe recommends only purchasing from companies that list all ingredients on their packaging and don’t include GP on that list. The same holds true for body wash, mouthwash, shampoos/conditioners, baby wipes, skin creams, deodorant, lotions, and ointments.
Be especially cautious with common processed foods that use propylene glycol. This includes salad dressings, margarine, box cake mix, sodas, frozen desserts (ice cream, yogurt), icing, and flavored coffee.
Go Natural With CBD
Elizabeth Moriarty, Clinical Herbalist and Formulator at HERBOLOGIE, says more and more cosmetic and body care companies “eschew” the use of GP as well as synthetic ingredients across the board. She recommends looking at the “ingredients we do not use” lists provided by many natural products companies.
Moriarty is the natural product formulator for Superior CBD. She worked with her lab to intentionally develop a 100 percent natural, plant-sourced product free of propylene glycol.
Axe says unfortunately, many of the food products containing PG don’t have propylene glycol-free options unless they’re homemade. On his website he lists several natural recipes for things like salad dressings and desserts. There’s even a homemade house cleaner recipe recipe.
