Cyclomethicone vs Petrolatum: which is worse?

What is Cyclomethicone?

Cyclomethicone is a term used for a mixture of cyclic silicones — primarily cyclopentasiloxane (D5) and cyclotetrasiloxane (D4). It is a lightweight, volatile silicone that evaporates from skin and hair after application.

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

Cyclomethicone: Cyclomethicone itself has a good short-term safety profile at cosmetic use levels. However, the EU has restricted specific cyclic silicones D4 (cyclopentasiloxane — now banned from rinse-off in EU) and D5/D6 (≤0.1% in rinse-off products) due to persistence, bioaccumulation, and potential endocrine-disrupting effects in aquatic organisms. Human health risk at cosmetic concentrations is considered low, but regulatory caution is appropriate. D5 has been studied for potential endocrine disruption in animals; evidence for human endocrine effects at cosmetic doses is not established.

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.