Ingredient deep-dive

Stearyl Dimethicone: Is It a Microplastic?

Sources reviewedSilicone

Stearyl Dimethicone is a silicone polymer. Its name identifies a chemical family, not the physical state, particle size or legal scope of a finished cosmetic; a silicon–oxygen backbone alone is not an exclusion.

Shared method updated October 6, 2026. Individual sources reviewed October 6, 2026.

What changed in this reference

Earlier pages inferred a yes/no microplastic verdict from an editorial high/medium/low grouping. Those labels were not measurements or health-risk grades. The shared answer, FAQ and regulation context now distinguish label names from physical particles. This entry also received the individual source review described below.

Stearyl Dimethicone is an alkyl-substituted siloxane polymer. CIR lists occlusive skin conditioning and describes manufacture using C18 components. Stearoxy Dimethicone and Stearyl Methicone are different named ingredients.

Identity corrections and evidence limits

The universal silicone-wax verdict and unverified replacements are withdrawn. Stearyl Dimethicone, Stearoxy Dimethicone and Stearyl Methicone have distinct definitions; sharing part of a name is not evidence that their material forms or functions are interchangeable.

The April 2022 CIR final report covers the described cosmetic uses and concentrations with non-irritating formulation. It found insufficient data for incidental inhalation from airbrush application. Its published and industry-submitted evidence is not a test of your product, environmental impact or current legal compliance.

Reported uses and functions

Occlusive skin conditioning

How the rules depend on the product

European Union

The EU restriction depends on polymer and particle criteria, exclusions and use. Abrasive microbeads have no transition after 17 October 2023. Otherwise, covered rinse-off cosmetics generally transition on 17 October 2027, other leave-on cosmetics on 17 October 2029, and make-up, lip and nail products on 17 October 2035. Microbeads, fragrance encapsulation and rinse-off uses have specific exceptions to those groupings. A name alone cannot establish compliance.

United States

The federal Microbead-Free Waters Act targets intentionally added solid plastic microbeads in rinse-off cosmetics for exfoliating or cleansing. It is not a blanket ban on all polymers or a product safety assessment. Other applicable rules require separate checking.

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Stearyl Dimethicone, common questions

Is Stearyl Dimethicone a microplastic?

Does a label match mean Stearyl Dimethicone is banned?

A label match alone cannot determine product compliance. EU context: The EU restriction depends on polymer and particle criteria, exclusions and use. Abrasive microbeads have no transition after 17 October 2023. Otherwise, covered rinse-off cosmetics generally transition on 17 October 2027, other leave-on cosmetics on 17 October 2029, and make-up, lip and nail products on 17 October 2035. Microbeads, fragrance encapsulation and rinse-off uses have specific exceptions to those groupings. A name alone cannot establish compliance. US context: The federal Microbead-Free Waters Act targets intentionally added solid plastic microbeads in rinse-off cosmetics for exfoliating or cleansing. It is not a blanket ban on all polymers or a product safety assessment. Other applicable rules require separate checking. Other substance-specific rules are separate from the microplastic definition; this reference is not a compliance determination.

Can a label show the particle count or health effect?

A label-name match does not measure particles, concentration, exposure or health effects. Polymer identity alone does not establish particle form or legal scope.

Sources and review scope

The Commission guide establishes the shared definition and transition context; CosIng inclusion is not ingredient approval. Label rules do not provide a particle assay. Ingredient-specific sources support the identity and scope stated here, not a tested product or measured health outcome.