Is the propylene glycol in your hair care products making you itch? Although the French Chemist Charles-Adolphe Wurtz didn’t identify propylene glycol (PG) until 1859, today it is a widely used chemical in everything from the foods we eat to the cosmetics and hair care products we use.[i] While the U.S. Food and Drug administration (the FDA) generally regards propylene glycol as safe and it readily biodegrades in the environment, there is growing concern in the scientific community about its role as an allergen. In fact, in 2018 the American Contact Dermatitis Society (www.contactderm.org) named propylene glycol its Allergen of the Year to draw attention to its role as a significant allergy causing agent. Studies vary but estimates range between 1% to 8% of all people alive today are allergic to PG with many not even realizing it.[ii]
Reasons for why propylene glycol is so widely used are easy to understand. PG is an inexpensive hydrophilic (water-loving) solvent with the added benefits of being a humectant, an anti-microbial preservative, a stabilizer and an anti-caking agent.[iii] However, despite these understandable benefits, the fact that it is used in everything from popular household cleaners to cake mix to aircraft deicing fluid to cosmetics presents a huge challenge to people with an immune system reaction to it. To make matters worse, according to Dr. Josh Axe, “propylene glycol increases your skin’s propensity to absorb whatever it comes in contact with. Considering the large amount of dangerous chemicals we encounter on a regular basis, this may be even more of a danger than the compound itself.”[iv]
Question #1 – Do I have an allergy do Propylene Glycol (PG)?
Sophia Emmanuel from NATURALLYcurly® writes that with respect to hair care products if you scalp is feeling dry or flaking or you develop a red rash on your hairline, ear, or neck you may be experiencing a PG reaction.[v] More broadly, if you are noticing any synthetic or manufactured product is regularly giving you eczema, hives, itchy skin, or a similar typical allergic reaction check the ingredient list. Unfortunately, propylene glycol goes by many names so read the ingredient list carefully. If the ingredient list for a product you’re having an issue with contains any of the items in the following chart you may have a propylene glycol allergy[vi]:
Some people can have quite severe reactions (including anaphylactic shock) to a different but similar sounding chemical called Polyethylene Glycol (PEG) also known as macrogols. The good news is that PG and PEG have very dissimilar chemical structures. According to Doctor Rachel Robinson, there does not appear to be cross-reactivity between Polyethylene Glycol and propylene glycol in patients. In other words, if you are allergic to PEG you are not any more likely than average to be allergic to PG.[vii]
Question #2 – How do I determine if I actually have an allergic reaction to Propylene Glycol?
If you determine you are consistently getting a reaction to a product with propylene glycol listed as an ingredient, you should see a professional allergist. Fortunately, patch tests (for skin allergy testing) and skin prick tests (for ingestion and inhalation allergy testing). Skin patch tests require 48-72 hours of wear before the Doctor can examine your skin for having a potential reaction, whereas skin prick test can typically be checked for a reaction during a single doctor’s visit. As with everything mentioned in this blog, should you have any concerns that you may have an allergy to propylene glycol please consult with your physician.
Question #3 – What do I do if my doctor determines I have an allergy to Propylene Glycol?
Unfortunately, over $4.6 billion dollars of PG is expected to be purchased this year for use in well over 5,000 common consumer products. As Joseph F. Fowler, Jr., MD clinical professor of dermatology notes, “if you’re allergic to it, it’s very tough to stay away from it.”[viii] Certainly, you will need to closely monitor ingredient lists and avoid products that come in contact with your hair, skin and scalp or that you ingest. Also avoid e-Cigarettes which use propylene glycol to produce their smoky looking vapor. The good news is there are a number of very helpful resources on the web and Facebook support groups that you should consider joining.
Desert Botanicals understands that propylene glycol is becoming a growing concern and issue for many of our customers. As a result, our product development team is currently working on a full set of PG-free hair care solutions that PG allergy sufferers will be able to use with confidence. Editors Note: Desert Botanicals launched its Propylene Glycol Free product line on October 5, 2021. It’s available for purchase in our shop.
REFERENCES:
[i] https://www.britannica.com/biography/Charles-Adolphe-Wurtz and “Focus on Propylene Glycol” The Dermatologist (Volume 21 – Issue 8 – August 2013 https://www.the-dermatologist.com/content/focus-propylene-glycol)
[ii] The Dermatologist (Volume 21 – Issue 8 – August 2013 https://www.the-dermatologist.com/content/focus-propylene-glycol) and “Safety Assessment of Propylene Glycol, Tripropylene Glycol, and PPGs as Used in Cosmetics” The International Journal of Toxicology (Vol. 31, October 11, 2012)
[iii] “Allergic and Immunologic Reactions to Food Additives” by Faith Gulekin and Duygu Kumbul Doguc, in Clinical Reviews in Allergy and Immunology (Vol. 45, Issue 1, October 1, 2013)
[iv]“The Dark Side of Propylene Glycol: Side Effects and Hot to Avoid Them” by Thomas Ropp, www.honeycolony.com (March 7, 2017)
[v] “The Signs You Have a Propylene Glycol Allergy” by Sophia Emmanuel https://www.naturallycurly.com/curlreading/curl-products/signs-you-have-a-propylene-glycol-allergy (February 18, 2020)
[vi] “Propylene Glycol and e-Cigarettes” https://www.propyleneglycolallergy.com/propylene-glycol-allergy-e-cigarettes/ (August 19, 2018)
[vii] “Cross-Reactivity Between Propylene Glycol and Macrogol?” American Academy of Allergy Asthma & Immunology https://www.aaaai.org/Allergist-Resources/Ask-the-Expert/Answers/Old-Ask-the-Experts/Cross-reactivity-between-propylene-glycol-and-macr (July 7, 2019)
[viii] “Allergen of the year may be nearer than you think” by Randy Dotinga MDedge.com (October 5, 2018)
