What is Polyethylene Glycol?
Polyethylene glycol, otherwise known as PEG, is a mixture of bonded polymer plastic compounds that are combined with glycol to make a thick sticky liquid. PEG is manufactured for use in paints, wood treatments, detergents, cleaners and coatings. Somehow, the chemical has worked its way into cosmetics, canine wellness products and medicine. Sounds healthy, right? You might be more familiar with a product called Myralax, which is sold as a laxative. When taken internally, PEG causes the colon to absorb water and produce a watery stool. I know you would not give Myralax to your dog but you might unknowingly give PEG to them if you are not carefully reading labels. The product my client was using was for her dog’s surgical wound. She had just gotten spayed. How I knew that it was her post-surgical gel that was causing her itching and hair loss was that PEG causes problems with it comes in contact with broken or damaged skin. PEG can accumulate in the body if it is able to penetrate the skin layer, affecting your dog’s skin and coat, nervous system, and beneficial bacteria. Polyethylene glycol functions as a “penetration enhancer,” which means it increases the permeability of the skin to allow the rapid absorption of substances through the skin layer. This allows a high absorption rate of any product containing polyethylene glycol.
The Cosmetic Ingredient Review board (CIR) studies chemical compounds found in cosmetics. (www.cir-safety.org) CIR notes that PEG compounds “should not be used on damaged skin”. If you look at polyethylene glycol’s Material Safety Data Sheet (MSDS), under “Skin Contact” it reads: “Immediately flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. Seek medical attention if warranted.” Um, how can anyone think that rubbing PEG on any type of skin is a good idea after reading this warning? The National Institute for Occupational Safety and Health (www.cdc.gov/niosh) notes: “Ethylene glycol is chemically broken down in the body into toxic compounds. It and its toxic by-products first affect the central nervous system, then the heart, and finally the kidneys. Ingestion of sufficient amounts can be fatal”. This warning is alarming for a topical product that directs you to rub it on damaged skin.
Another issue that polyethylene glycol has is contamination. Depending on the way polyethylene glycol is manufactured, PEG can contain contaminants like ethylene oxide and 1,4-dioxane. polycyclic aromatic compounds, lead, cobalt, nickel, cadmium, and arsenic. The International Agency for Research on Cancer (www.iarc.fr) has classified ethylene oxide as a known human carcinogen that can harm the nervous system and interfere with human development. 1,4-dioxane is listed as a possible human carcinogen. 1,4-dioxane is a chemical that remains in the environment for long periods of time because it does not easily degrade. If the above wasn’t enough, polyethylene glycol also destroys the beneficial bacteria found on your dog’s skin and inside their stomachs. Dogs rely on these bacteria for a healthy immune system and a balanced pH level. Sadly, most manufacturers don’t know about all the research being done into polyethylene glycol and its derivatives. From the information that I found, it would not make sense for natural product and cosmetic manufacturers to use PEG and PEG derivatives but they do. Hopefully, as more information becomes available and more people complain about the use of the ingredient, they will leave polyethylene glycol to the paint and coatings manufacturers.
In the case of our canine friends, my main concern comes with topical medication geared toward the healing of damaged skin and wounds. I encourage you to keep reading labels and looking up ingredients. If you don’t know what something is, research it and find out if it is safe for you and your dog. Don’t rely on the manufacturer.