Do you want to make sure you are using toxic-free makeup and skin care products? So do I. One of the most controversial ingredients I have seen in my career as a consumer product researcher and non-toxic consultant is dimethicone. In fact, I have been researching it for years now because there is a lot of negative information about it on the Internet. For example, some say that it causes acne because it coats the skin and prevents it from breathing. Others even say that it causes endocrine disruption and reproductive toxicity. In this post, you will learn my findings about dimethicone safety so you can make informed and practical decisions.
How I do research
To begin with, I formulate my opinions by reading scientific studies on the subject, not just hear-say. I believe it is important to pass along only accurate information, so I turn to scientific and medical sources. Therefore, when you hear scary claims about a product or an ingredient, I encourage you to ask for the sources of their information.
I say this because a lot of bloggers simply repeat what they read on the Internet. Once something is written, it can take on a life of its own. But before I publish something, I always do my best to track down the original sources of information, so I am not simply repeating something that may not be true. It takes a lot more time to do things this way, but it is my obsession to find the truth. But, I digress.
Here is what I have learned about this widely used ingredient.
What is dimethicone?
First, its chemical name is polydimethylsiloxane (PDMS), and it is also known simply as silicone oil.
Second, the EWG Skin Deep database rates it 1-3 depending on the use (used to be 3) on a scale from 1 to 10 (with 10 as most toxic) and indicates that safety data is limited. Further, it does not list any concerns associated with endocrine disruption or reproductive toxicity. However, while the Skin Deep database is the best tool we as consumers have for quick research, it has its limitations. So, I always try to read the original research that the EWG uses to assign a rating to an ingredient.
Third, the Cosmetic Ingredient Review (CIR) Panel reviewed dimethicone safety for use in cosmetics. As a result, the panel compiled all available data on dimethicone from over 100 independent studies. Although I do not take the panel’s conclusions as the last word on safety, their assessments are helpful, if only to provide some context.
Is dimethicone bad for skin?
First of all, in skin irritability tests that the CIR refers to in its report, the scientist used this ingredient in the undiluted form. In contrast, this would never happen with skin sensitizers such as formaldehyde-releasing preservatives. But despite its undiluted form, the scientists did not find it to be an allergen in animal studies. Also, after tests on 83 humans at 5% concentration, no skin reactions occurred.
Moreover, I found two studies (you can access them here and here) that talk about its effectiveness in the treatment of hand contact dermatitis and prevention of contact dermatitis caused by SLS (Sodium Lauryl Sulfate).
Does it cause any health problems?
For starters, I have read a comprehensive write up on dimethicone safety in Ullmann’s Encyclopedia of Industrial Chemistry. The publication points out that it is a well-researched substance because of its broad applications. Thus, the 708-page manuscript states that it showed no health effects, even when scientists administered it orally in big doses.
Furthermore, the CIR Expert Panel reports that the skin does not absorb dimethicone because of its large molecular weight. In addition, the European Union Chemicals Agency database reports no health effects.
On the other hand, there is some limited evidence regarding negative effects with inhalation exposure of aerosol formulation. So, I do not recommend this ingredient in spraying products.
Is dimethicone a carcinogen?
According to the CIR report, there are no links to cancer even when animals ate this ingredient in big doses. Additionally, the World Health Organization reports the lack of carcinogenicity evidence in long-term feeding studies in rats at alternating doses up to 1500 mg/kg per day or up to 1875 mg/kg per day (source).
Does it cause acne?
Apparently, there are claims on the Internet that it creates an unbreathable layer on the skin, which may make the skin dry and even cause acne. So, finding no concerning information on dimethicone safety, I was ready to try toxin-free makeup with it.
As a result, I have been using Crunchi’s non-toxic liquid foundation for over a year now and have not had any acne problems. On the contrary, I have found that this ingredient helps the foundation to spread evenly, conceal wrinkles, and in some cases even create a dewy effect.
Is dimethicone an endocrine disruptor?
Again, per the CIR report, there are no links to endocrine disruption. And I have not found any medical studies outside of the report to link dimethicone to hormone disruption.
In addition, the World Health Organization (WHO) allows its use in food as an anticaking and antifoaming agent (source). It does not mean, though, that I recommend eating food with it or any other processed food. It simply means that it is a food-grade ingredient.
Is dimethicone toxic for the environment?
Obviously, I was concerned about the effects of this widely used ingredient on the environment.
For instance, Ullmann’s Encyclopedia of Industrial Chemistry explains that it is mostly non-biodegradable but is not harmful to aquatic life (plankton, crustacea, mussels, fish). Even silicone fluid administered with food showed no effect on fish. Also, the symbiosis of microorganisms such as bacteria and algae has not been disturbed by this ingredient dissolved in water. The European Union Chemicals Agency database also cites no ill effects on aquatic life, confirming dimethicone safety for the environment.
While it is non-biodegradable, it is eliminated from sewage water because it is absorbed by sewage sludge. The reason it ends up in the oceans is that sewage sludge is often dumped into the oceans.
Are polydimethylsiloxanes safe for the environment?
Polydimethylsiloxanes are a group of chemicals dimethicone belongs to. There are reports that they exhibited toxic effects on fish. However, the polydimethylsiloxanes at issue were emulsifiers and were at concentrations up to 10,000 ppm. So, it is not believed that dimethicone as used in cosmetics is harmful to the environment.
And the good news is that polydimethylsiloxanes are non-bioaccumulative. It means that as soon as the fish were transferred out of the environment with polydimethylsiloxanes, they were rapidly eliminated from the fish tissue.
In addition, polydimethylsiloxanes can be degraded and absorbed by the environment if a non-biological step is taken initially such as burning. You can read more about that here.
What are other forms of silicone?
In addition to dimethicone, there are other types of silicone, such as phenyl trimethicone, cyclopentasiloxane, and PEG-10 dimethicone.
Is phenyl trimethicone safe?
This white silicone fluid is highly water resistant and by trapping water in skin or hair, it adds flexibility. So, it works as a hair and skin-conditioning agent, and an antifoaming agent. Thus, the EWG Skin Deep database rates it 1 out of 10 (with 10 as most toxic) but indicates limited safety data.
Furthermore, the Cosmetic Ingredient Review (CIR) Expert Panel considers phenyl trimethicone safe for use in cosmetics and personal care products. In fact, the panel reviewed acute oral data showing that the ingredient was relatively non-toxic. Additionally, it reviewed acute and subchronic dermal studies that also showed its non-toxic nature.
Specifically, phenyl trimethicone is nonmutagenic, nonirritating to the skin and eyes, and is not a sensitizer to humans. Note also that the tested doses were larger than the concentrations used in cosmetics and personal care products. This fact should provide even more peace of mind. Moreover, because the UV spectrum indicated only weak absorbance at 327 nm, the panel concluded that it is not a phototoxicant or a photosensitizer (source).
Finally, just as in the case with dimethicone safety, the European Chemicals Agency has classified no hazards based on the notifications submitted by companies. As a result, the general provisions of the Cosmetic Regulation of the European Union allow the use of phenyl trimethicone in cosmetics and personal care products marketed in Europe.
Is cyclopentasiloxane safe?
Unlike dimethicone, cyclopentasiloxane raises some concerns, in my opinion. You can read more about this ingredient in my post about cyclopentasiloxane safety. My personal recommendation is to reduce your usage of products with it. For instance, one of such products is Old Spice antiperspirant & deodorant.
Is PEG-10 dimethicone toxic?
To begin with, PEG-10 dimethicone is a synthetic polymer that consists of PEG (polyethylene glycol) and dimethicone. Due to the presence of PEG, it is an ethoxylated ingredient made through the process of ethoxylation. As a result, it may contain potentially toxic manufacturing impurities such as 1,4-dioxane. Thus, the EWG Skin Deep database rates it 5-8 with robust safety data and describes it as a carcinogen.
Therefore, I do not recommend products with ethoxylated ingredients. Namely, beware of such ingredients as PEGs, polysorbates, and those whose names end with “-eth” (e.g., Laureth). For example, Bare Minerals foundation uses PEG-10 dimethicone in their formulation. To read about a safe liquid foundation with dimethicone, visit my post The Non-Toxic Foundation that Works So Well.
Conclusion about dimethicone safety in toxin-free makeup
To sum up, I have not found any evidence that this cosmetic ingredient is toxic when applied on the skin. Thus, I believe it is okay to use it in toxin-free makeup, skin care, and personal care products. I do not think it can increase the risks of allergic contact dermatitis, allergic reactions, skin irritation, cancer, and endocrine disruption.
Finally, please visit my shop to find the perfect skin care, clothing, and household products for you. Feel free to book a consultation with me to seek help with healthy living. Also, consider joining the Savvy Consumer Circle, a service for people who want to go deeper with non-toxic healthy living.
Your Superpower To Read Ingredients
Imagine looking at the ingredients of any shampoo, conditioner, lotion, or cream and in a matter of seconds being able to decide if it is safe to use!
With this easy unprecendented method, you will be able to spot potentially harmful personal care or skincare products that may cause irritation, an allergic reaction, or increase the risk of endocrine disruption or cancer.