Ingredient
Cyclopentasiloxane (D5)
What is Cyclopentasiloxane (D5)?
Cyclopentasiloxane, also known as D5, is a type of silicone. It is created through a chemical process involving the hydrolysis and condensation of silanes to produce cyclic siloxane compounds.
It is primarily used in personal-care products for its smoothing, non-greasy feel and quick evaporation. However, health evidence is mixed. Some studies have raised concerns about its potential for bioaccumulation and environmental persistence, but regulatory agencies have not agreed on its human health impact.
When you see it on a label, know that it's often included to give products a silky texture and spreadability, but its environmental impact is a topic of ongoing research.
Commonly found in: Body Lotion, Lip Care, Skin Care, Sunscreen
What to watch
- Concerns about bioaccumulation in the environment have been raised.
- Some evidence suggests potential endocrine disruption in animal studies.
Benefits
- Provides a smoothing effect on the skin without a greasy residue.
- Evaporates quickly, leaving a pleasant skin feel.
Cyclopentasiloxane is not specifically restricted by the FDA and is generally recognized as safe for cosmetic use.
Research shows mixed results; some studies suggest limited environmental impact, while others raise concerns over bioaccumulation.
Cyclopentasiloxane is synthetic and not derived from animal sources, generally considered vegan-friendly.
The European Chemicals Agency has concerns over its persistence, bioaccumulation, and toxicity in the environment.
Sources: Union List of Cosmetic Ingredients · Siloxanes in the environment: A review
Scout's take
Cyclic silicone classified by the EU's ECHA as vPvB (very persistent, very bioaccumulative). REACH-restricted in wash-off cosmetics since 2020 and listed under Canada's CEPA toxic substances. Aquatic-toxic.
More from Scout's analyses
Cyclic silicone designated a Substance of Very High Concern by the EU's ECHA in 2018 for environmental persistence and bioaccumulation. Restricted in rinse-off products in the EU since 2020. Leave-on use (like sunscreen) remains permitted but contested.
from the analysis of Blue Lizard Sensitive Mineral Sunscreen SPF 50Cyclic siloxane restricted in EU rinse-off cosmetics for environmental persistence (PBT concerns).
from the analysis of Proactiv Emergency Blemish Relief (5% Benzoyl Peroxide)EU SVHC since 2018; persistent and bioaccumulative.
from the analysis of EltaMD UV Clear Broad-Spectrum SPF 46Found in 5 products
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