Hexabromocyclododecane

Hexabromocyclododecane, commonly abbreviated as HBCD, is a brominated cycloaliphatic flame retardant identified under CAS 25637-99-4. It is commercially available under trade names including CD 75, HBCD HT, Saytex HBCD, and Pyrovatex 3887. No E-code designation applies to this substance.

HBCD is used primarily in expanded and extruded polystyrene insulation boards for the construction sector, where it interrupts combustion by releasing bromine radicals that quench flame propagation in the polymer matrix. It is also applied in textile back-coatings and electronic housings requiring UL 94 flame-class compliance.

HBCD is subject to strict regulatory controls under the Stockholm Convention on Persistent Organic Pollutants and is listed as a Substance of Very High Concern under REACH, with use now largely restricted across the EU. Procurement teams should verify applicable exemptions and confirm compliant sourcing documentation before ordering.