Dimethiconol

What Is It?

Dimethiconol is a silicone based polymer that resembles Dimethicone, except that molecules of Dimethiconol end with hydroxyl (-OH) groups. Dimethiconol derivatives that may be also be used in cosmetic products include Dimethiconol Arginine, Dimethiconol Beeswax, Dimethiconol Behenate, Dimethiconol Cysteine, Dimethiconol Meadowfoamate, Dimethiconol Methionine, Dimethiconol Panthenol, Dimethiconol Stearate, Dimethiconol/Silsesquioxane Copolymer, Trimethylsiloxysilicate/Dimethiconol Crosspolymer and Acrylates/Dimethiconol Acrylate Copolymer.

In cosmetics and personal care products, Dimethiconol and its derivatives are used in the formulation of a wide range of cosmetic and personal care products including cosmetic creams and lotions, suntan products, bath soaps, lipstick, shampoo and hair care products. The most widely used ingredient in this group is Dimethiconol.

Why Is It Used?

The following functions have been reported for these ingredients.

  • Antifoaming agent — Dimethiconol
  • Antistatic agent — Dimethiconol/Silsesquioxane Copolymer
  • Film former – Dimethiconol/Silsesquioxane Copolymer, Trimethylsiloxysilicate/Dimethiconol Crosspolymer, Acrylates/Dimethiconol Acrylate Copolymer
  • Hair conditioning agents — Dimethiconol Arginine, Dimethiconol Cysteine, Dimethiconol Methionine, Dimethiconol Panthenol, Dimethiconol/Silsesquioxane Copolymer
  • Hair fixative – Dimethiconol/Silsesquioxane Copolymer
  • Skin-conditioning agent — emollient — Dimethiconol, Dimethiconol Meadowfoamate
  • Skin-conditioning agent — miscellaneous – Dimethiconol/Silsesquioxane Copolymer
  • Skin-conditioning agent — occlusive — Dimethiconol Beeswax, Dimethiconol Behenate, Dimethiconol Stearate
  • Viscosity increasing agent — nonaqueous – Trimethylsiloxysilicate/Dimethiconol Crosspolymer

Scientific Facts

Silicon, the backbone of Dimethiconol, is a common element in the earth. Silicon, like carbon can form polymers, consisting of chains of silicon atoms. Polymers of silicon with oxygen, hydrogen and carbon are called silicones. Dimethiconol is a mixture of siloxane polymers referred to as polydimethylsiloxane terminated with hydroxyl (-OH) groups. Dimethiconol can be combined with other molecules, such as the amino acids (arginine, cysteine and methionine) or fatty acids (behenic acid, stearic fatty acids from meadowfoam seed oil) or other compounds to form derivatives of Dimethiconol that are useful as cosmetic ingredients.

Safety Information

The safety of Dimethiconol, Dimethiconol Arginine, Dimethiconol Beeswax, Dimethiconol Behenate, Dimethiconol Cysteine, Dimethiconol Meadowfoamate, Dimethiconol Methionine, Dimethiconol Panthenol, Dimethiconol Stearate, Dimethiconol/Silsesquioxane Copolymer, Trimethylsiloxysilicate/Dimethiconol Crosspolymer and Acrylates/Dimethiconol Acrylate Copolymer has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated scientific data and concluded that these ingredients were safe for use in cosmetics.

CIR Safety Review:

The CIR Expert Panel reviewed the group of silicone polymer derivatives (Dimethiconol, Dimethiconol Arginine, Dimethiconol Beeswax, Dimethiconol Behenate, Dimethiconol Cysteine, Dimethiconol Meadowfoamate, Dimethiconol Methionine, Dimethiconol Panthenol, Dimethiconol Stearate, Dimethiconol/Silsesquioxane Copolymer, Trimethylsiloxysilicate/Dimethiconol Crosspolymer and Acrylates/Dimethiconol Acrylate Copolymer) together because they are similar in composition and use. For this reason, the CIR Expert Panel was able to consider the scientific information available for all the ingredients to support the review of the safety of these ingredients for use in cosmetics and personal care products.

The CIR Expert Panel considered it unlikely that any of the Dimethiconol ingredients would be significantly absorbed into the skin due to the large molecular weights of these polymers. The CIR Expert Panel also reviewed safety data on Dimethiconol including data that indicated that it did not cause mutations or cancer. Dimethiconol was not an eye irritant or a dermal irritant or sensitizer at concentrations used in cosmetics and personal care products.

Based on the available data, the CIR Expert Panel concluded that Dimethiconol and derivatives of Dimethiconol were safe for use in cosmetics and personal care products. Dimethiconol and its derivatives may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.

Link to the EU Cosmetic Regulation: http://europa.eu/legislation_summaries/consumers/product_labelling_and_packaging/co0013_en.htm

More Scientific Information

Siloxanes, or more precisely, organ-substituted polysiloxanes, are linear or cyclic polymers of monomeric silicon/oxygen molecules. The polymeric backbone is made up of alternating silicon and oxygen atoms. The silicon atoms may carry a wide variety of substituents which can be the same or different. Dimethiconol is a mixture of fully methylated linear siloxane polymers terminated with hydroxyl groups.