Dimethicone vs Petrolatum: which is worse?

What is Dimethicone?

Dimethicone is a silicone polymer (polydimethylsiloxane) that exists as a clear, odorless oil or gel depending on molecular weight (viscosity grades 50–12,500 cSt). It is one of the most widely used cosmetic ingredients globally for its unique skin-feel properties.

What is Petrolatum?

Petrolatum is a semi-solid mixture of hydrocarbons derived from petroleum refining. It forms an occlusive barrier on the skin surface, sealing in moisture and protecting against external irritants. It has been used in skincare since 1872.

Documented risks

Dimethicone: Dimethicone has an excellent safety record. The CIR has reviewed it extensively and confirmed safety at cosmetic use concentrations. It is non-allergenic, non-comedogenic, and does not penetrate intact skin. It is FDA-approved as an OTC skin protectant (1–30%). Environmental concerns exist because high-molecular-weight dimethicone is not biodegradable and accumulates in aquatic sediments; this is a sustainability concern rather than a human health issue. No carcinogenic or endocrine effects are documented.

Petrolatum: Fully refined white petrolatum (as used in cosmetics) is considered safe by the FDA and CIR, and is an FDA-approved OTC skin protectant. The EU restricts petrolatum unless full refining history is known due to concerns about polycyclic aromatic hydrocarbons (PAHs) in inadequately refined grades. Cosmetic-grade petrolatum in the US undergoes extensive refining that removes PAHs. It does not penetrate the skin, is non-comedogenic in pure form, and has no evidence of systemic toxicity or endocrine disruption at cosmetic use.