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emollient · solvent

Cyclopentasiloxane

Fearmongered, actually fine·Strong evidence

A lightweight, volatile silicone that gives serums and primers their silky slip and quick-evaporating finish. Human safety data are reassuring; the EU restriction on this ingredient in rinse-off products is about environmental persistence in waterways, not skin safety.

The myth vs the evidence

Myth: cyclopentasiloxane is "banned" because it is dangerous to skin. Evidence: the EU capped D5 (and D4) at 0.1% in wash-off cosmetics under REACH because these silicones persist and bioaccumulate in aquatic environments, a separate concern from topical safety. The SCCS did not find it unsafe for skin contact at cosmetic levels, and it remains permitted in leave-on products.

Worth knowing

  • Restricted in the EU

EU limits cyclopentasiloxane (D5) to a maximum of 0.1% in rinse-off cosmetic products for environmental reasons under REACH; leave-on use is not restricted on safety grounds.

Products with Cyclopentasiloxane

References

Cosmetic information for general education, not medical advice. Concern is graded on cited evidence, never on hazard-score lists. See how we score.