PEG Compounds, Siloxanes & Petrolatum
Temporary surface moisture that can dry out your skin
Part 1 of my series on the common cosmetics ingredients that carry the highest risk of potential harm to our health.
PEG Compounds
Polyethylene Glycol (PEG) and Polypropylene Glycol (PPG) are compounds derived from petroleum. They are commonly used in cosmetics as thickeners, softeners, moisture carriers, surfactants, etc. The molecule itself, (Poly)ethylene Glycol, is considered non-toxic and inert. However, depending on the manufacturing process, it may create carcinogenic byproducts called ethylene oxide and 1,4-dioxane. [1][2][6]
The FDA does not require these chemicals (ethylene oxide and 1,4-dioxane) to be listed on ingredient labels because they are byproducts of the manufacturing process (called ethoxylation). Alternative methods exist (such as vacuum-stripping), but it is uncommon for companies to use them. One way to avoid exposure is to purchase certified products under the USDA National Organic Program, as they do not allow ethoxylation. [3]
The FDA says they have “not independently conducted a hazard identification and risk assessment concerning exposure to 1,4-dioxane as a contaminant in cosmetic products.” [4] Yet, cosmeticsInfo.org says that reports expressing concerns about 1,4 dioxane in cosmetics are sensationalized, and levels are so low that there is no need for concern. [5]
However, PEGs can also increase the skin’s permeability to allow increased absorption of a product, which can include harmful ingredients. [2]
They come in many names, but some examples are Peg-10 Dimethicone, PPG-12 PEG-50 Lanolin, and Laureth-4, Ceteareth-30. [1] There are so many possible combinations of these molecules to list all of them.
Photo: Wikimedia Commons
References:
1. Think Dirty
2. David Suzuki Foundation
3. Campaign For Safe Cosmetics
4. FDA
5. CosmeticsInfo.org
6. Journal of Toxicology and Public Health
Siloxanes
These silicone-based compounds are used in cosmetics to soften, smooth, and moisten. [1] Due to concentration limits set, these ingredients are effectively banned in the EU. [2]
The siloxane compounds studied closely in cosmetics are:
D4 (cyclotetrasiloxane)
D5 (cylcopentasiloxane)
D6 (cyclohexasiloxane)
PDMS (Polydimethylsiloxane silicone polymers) are produced from D4.
Dimethicone is a PDMS commonly used in cosmetics and may contain traces of D4 and D5. [1][3][4][6][7]
Recent studies have raised concerns about the potential toxicity of these siloxanes.
D4
The EU’s Scientific Committee on Consumer Safety (SCCS) and the European Chemicals Agency’s (ECHA) Member State Committee classify D4 as toxic to mammalian and aquatic reproduction, persistent (not biodegradable), and bioaccumulative (accumulates in the environment). [2][4][5]
Additionally, there is clear evidence that D4 can be found in a wide range of organisms, fish in particular. [5] Siloxanes are likely to be released into sewage systems through “rinse-off” products (shampoo, soap, etc) and partially adsorbed onto sludge in wastewater treatment plants. They are also released into aquatic environments via the discharge of wastewater. [3]
The European Union classifies D4 as an endocrine disruptor. [8]
D5
The SCCS has recommended specifically that D5 should be avoided altogether in hair styling aerosols and sun care sprays. Additionally, D5 may contain traces of D4. [2][7] D5 can also influence neurotransmitters in the nervous system. [1] However, in the US, they are considered safe under current practices of use. [2]
Photo: silicones.eu
References:
1. David Suzuki Foundation
2. CosmeticsInfo.org
3. Science Direct
4. European Commission Scientific Committee on Consumer Safety (SCCS) Opinion on Cyclomethicone
5. ANNEX 2 to MSC opinion on persistency and bioaccumulation of D4 and D5
6. Cosmetics and Toiletries Magazine
7. SCCS opinion on decamethylcyclopentasiloxane (cyclopentasiloxane, D5) in cosmetic products
8. Vermont Department of Health
Petrolatum
Petrolatum is used as a moisturizing agent in cosmetics. Related petroleum by-products, mineral oil and petroleum distillates, are also used in cosmetics. [1]
I found a lot of conflicting information on this ingredient. While there is concern on the internet about a potential risk that petrolatum can be contaminated with a carcinogen called PAHs (polycyclic aromatic hydrocarbons), CosmeticsInfo.org goes so far as to call this a myth. [1][2][3] They state, “The petrolatum used in cosmetics and personal care products is a highly refined grade that must meet very strict safety standards, which includes limits on the content of PAHs,” however, how do we know this is true when the refining history is unknown to the public and there are no limits set by the FDA? I was unable to find a statement by the FDA regarding PAHs in petrolatum.
As usual, the EU takes the most cautious route and only allows it in cosmetics if the full refining history is known. [4]
The small bit of good news is there is evidence that we do not absorb mineral oil into the deeper levels of our skin. [5]
If you’d like to avoid this ingredient, look out for these other ingredient names: petroleum jelly and paraffin oil.
Header Image by FP_atkwork on Freepik
Featured Image by FP_atkwork on Freepik