At a glance
| Chemical family | Chlorinated hydrocarbon — industrial by-product / persistent organic pollutant |
| CAS number | 87-68-3 |
| Classification | IARC Group 2B (possibly carcinogenic to humans); Stockholm Convention Annex A (2017) + Annex C; EU SVHC; Canada SOR/2025-270 prohibited |
| Where you encounter it | By-product of chlorinated solvent manufacturing (carbon tetrachloride, perchloroethylene, trichloroethylene); environmental contaminant near chemical plants; detectable in ambient air and dust |
| Sleep micro-environment relevance | Not intentionally added to any product — enters the bedroom as environmental contamination in dust and air near industrial sources |
Regulatory & certification status
| European Union | SVHC (Candidate List). POP Regulation (EU) 2019/1021 — listed under Annex A (elimination) and Annex C (unintentional production). REACH Annex XVII does not need a separate entry because the POP Regulation supersedes. Regulatory — European Union authority |
| United States | EPA: listed as a hazardous air pollutant (Clean Air Act). CERCLA hazardous substance. Not manufactured commercially. California Proposition 65 listed (cancer). Regulatory |
| Canada | Prohibited under the Prohibition of Certain Toxic Substances Regulations, 2025 (SOR/2025-270), in force 30 June 2026 — manufacture, use, sale and import are banned. Regulatory — Canada authority |
| International | Stockholm Convention Annex A (elimination, 2017) + Annex C (unintentional production). IARC Group 2B. UNECE LRTAP Protocol on POPs. Regulatory |
What it is
Hexachlorobutadiene is a dense, oily liquid with six chlorine atoms on a four-carbon chain. It has no deliberate consumer use — it is generated as an unwanted by-product during the manufacture of other chlorinated chemicals (carbon tetrachloride, perchloroethylene, trichloroethylene). IARC classifies it as Group 2B based on kidney tumour evidence in animals. The Stockholm Convention added HCBD to Annex A (elimination) and Annex C (unintentional production) in 2017, recognising both its persistence and the impossibility of eliminating it by banning 'production' — since it is a by-product, the obligation is to minimise unintentional release.
Where it shows up in bedding
HCBD does not appear in bedding products. Its sleep-environment relevance is geographic: homes near chlorinated chemical manufacturing facilities or contaminated sites may have elevated HCBD in household dust and indoor air. It is volatile enough to enter buildings from contaminated soil (vapour intrusion) and persistent enough to accumulate in dust. For most bedrooms, HCBD is not a meaningful exposure — but for homes near specific industrial sites, it can be.
Citations
- IARC (1999). Hexachlorobutadiene. IARC Monographs Vol. 73. Source Peer-reviewed
- Stockholm Convention (2017). Listing of Hexachlorobutadiene — Annex A and Annex C. Source Regulatory
- ECHA. Substance Information: Hexachlorobutadiene. Source Regulatory
Frequently asked questions
Is hexachlorobutadiene in any consumer products?
No. HCBD has no deliberate consumer or industrial use — it is an unwanted by-product of chlorinated chemical manufacturing. It is not an ingredient in any product sold to consumers. Its environmental presence comes from industrial emissions and waste, not from products.
Should I be concerned about HCBD in my bedroom?
For most homes, no. HCBD exposure is primarily an issue for communities near chlorinated chemical plants or contaminated sites. If your home is near such a facility, vapour intrusion from contaminated soil could bring HCBD into indoor air. Environmental monitoring data for your area (available from EPA or provincial agencies) is the way to check.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-07. If you find a factual error, contact us.