Cyclopentasiloxane vs Brominated Flame Retardants: which is worse?

What is Cyclopentasiloxane?

Cyclopentasiloxane is a volatile silicone (D5) used for smooth, silky texture.

What is Brominated Flame Retardants?

Brominated flame retardants (BFRs) are a class of synthetic chemicals added to consumer products and materials to reduce flammability. They include polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and others. While not direct food additives, they contaminate the food supply through environmental pathways and food packaging.

Documented risks

Cyclopentasiloxane: Persistent and bioaccumulative; the EU restricts D5 in wash-off products over environmental and endocrine concerns. The US has no restriction.

Brominated Flame Retardants: PBDEs and other BFRs are endocrine disruptors, neurodevelopmental toxicants, and probable carcinogens. They accumulate in human adipose tissue, breast milk, and blood. PBDEs were found in 100% of samples in multiple US population biomonitoring studies. US women have PBDE body burdens 10-100 times higher than European women, reflecting the US's historically heavy PBDE use before bans. Neurodevelopmental effects: multiple studies have associated prenatal PBDE exposure with lower IQ, attention deficits, and behavioral problems in children. A 2012 Environmental Health Perspectives study found inverse associations between PBDE cord blood levels and child IQ and behavioral outcomes. Thyroid disruption: BFRs structurally mimic thyroid hormones and compete with thyroid hormone binding proteins, disrupting the thyroid axis — critical for fetal brain development. Carcinogenicity: some PBDEs are associated with thyroid cancer risk in human studies. PBDEs enter the food supply primarily through fatty fish (salmon, tuna), meat, dairy, and some contaminated produce from biosolid-amended soils.