Or the most popular ingredient found in lifestyle products from beauty cosmetics to processed food.
Propylene glycol. Behind this obscure term hides one of the most common ingredients found in cosmetics and personal care products, but also in processed food and medications. A synthetic alcohol, propylene glycol has multiple properties which make it indispensable to the beauty and pharmaceutical industries. “It’s present in about half of all topical products. It’s an extremely useful ingredient since it acts in multiple functions. It’s an oil free moisturizing ingredient, a solvent, it’s penetrant to help medications through the skin barrier, and preservative,” explains US-based dermatologist Andrew Scheman, from the American contact dermatitis society.
Allergy risk of propylene glycol
While it is widely used and quite useful, concerns have been raised in recent years regarding its safety. Indeed, propylene glycol has been tied to a range of health issues. The US Food and Drug Administration (FDA) stated that propylene glycol is "generally recognized as safe,” cases of eye and skin irritations, allergies and contact urticaria have been reported in the scientific literature. Taking a closer look at the data suggests however that there is no cause for alarm however.
“It is a very safe ingredient for the most part. Like many other safe ingredients, some people may develop allergy to it. We want to emphasize that this is an extremely useful ingredients that should continue to be used in products, however, there will be some individuals that will have skin reactions due to contact allergy to propylene glycol and may not tolerate products which contain it,” Scheman says.
Propylene glycol and cancer
A more preoccupying fact may be that some scientists have tied propylene glycol to a raised risk of cancer or to neurodevelopmental issues. A 2012 study for example showed that this compound was linked to the death of brain cells.
It’s worth pointing out, however, that these studies do not prove that propylene glycol is the cause of the health problems identified. They rely on correlations. Most of these studies have been done on animals, and are not perfectly applicable to humans. Furthermore, other research have reached opposite conclusions.
Beyond the risk of allergies which has been well established, it’s therefore difficult to assess the long-term risk that this particular chemical poses to human’s health, as the data can be confusing and contradictory. It’s likely that most of the concerns are overblown, especially since cosmetics contain very low concentrations of propylene glycol which are unlikely to harm in any way. Applied on the skin, these products have no effect on the brain or other organs.
Propylene glycol in cosmetics
So keep moisturizing without fear or cancer or neurological diseases. As for the allergy risk, knowing about it and being prepared to switch face creams or body lotions in case of redness and irritations is a good first step to take care of your skin.
“We are not advocating that people avoid products with propylene glycol. We simply want to make them aware that allergy to this ingredient is not rare and to be aware of this possibility. We need to continue to collect data on the prevalence of allergy to propylene glycol to monitor whether or not this is becoming a more frequent problem,” Scheman concludes.
Writer: Léa Surugue