At a glance
| What this is | A brominated flame retardant used in expanded/extruded polystyrene building insulation and as a back-coating on upholstery and other textiles |
| CAS number | 25637-99-4 (also 3194-55-6) |
| Carcinogen status | Not classified as a carcinogen. The concern is persistence/bioaccumulation and endocrine + developmental-neuro toxicity |
| Key hazard | A persistent organic pollutant (POP); endocrine disruptor; US EPA rates its developmental health effect as "high hazard" |
| Where you encounter it | The textile back-coating of upholstered furniture and some furnishings, building insulation, and the house dust they shed into |
| Sleep micro-environment relevance | Found to be the most abundant flame retardant in bedroom dust in one study, with bedding identified as a crucial source |
| Regulation | Stockholm Convention Annex A (elimination, 2013); EU REACH authorisation — a phased-out but persistent legacy |
What it is
Hexabromocyclododecane (HBCD) is a brominated cyclic flame retardant with two principal uses: expanded and extruded polystyrene (EPS/XPS) building insulation, and the back-coating applied to upholstery and other textiles to slow ignition. That textile use is the one that belongs in a bedroom guide — it places a brominated flame retardant in the fabric layer of furniture and furnishings. Peer-reviewed — Feiteiro et al. 2021
HBCD's defining property is persistence. It is a recognised persistent organic pollutant: persistent, bioaccumulative, toxic and capable of long-range transport — which is why it was added to the Stockholm Convention's elimination list in 2013. Regulatory — Stockholm Convention, HBCD Annex A (2013) Unlike an additive that fades, a POP lingers in products, dust and bodies for a long time.
How it relates to the bedroom
The route: out of treated textiles, into bedroom dust
Like the other brominated flame retardants, HBCD is an additive — not chemically bound — so it migrates out of treated textiles and furniture and accumulates in house dust. The bedroom evidence here is unusually direct: in a study of indoor dust across microenvironments, HBCD was the most abundant flame retardant measured in bedroom dust, and its levels in bedding dust correlated with room dust, leading the authors to conclude that bedding was one of the crucial sources of HBCD in the bedroom — and to flag dermal contact with bedding and furniture, alongside dust ingestion, as an exposure route. Peer-reviewed — Wang et al. 2023
The concern: development, not cancer
HBCD is not an IARC carcinogen; its hazard profile is different and arguably more relevant to a nursery. It is an endocrine disruptor with documented thyroid, neurodevelopmental and reproductive effects, Peer-reviewed — Feiteiro et al. 2021 and the US EPA categorises its developmental health effect as "high hazard." Estimated body burdens are highest in toddlers, which is exactly the group for whom a developmental-neurotoxicant matters most. Peer-reviewed — Barghi et al. 2017
Keeping it in proportion
HBCD is being eliminated, and measured intakes for the general population are generally below toxicological reference values — so this is a declining, mostly low-level exposure. Peer-reviewed — Barghi et al. 2017 (body-burden estimates with developmental caveat) But because it is persistent and was used for decades, it remains widespread in existing furniture, textiles, insulation and dust — a legacy that decays slowly, which is why a recently made, FR-free mattress and good dust control both help. Inferred — POP persistence means legacy products and dust keep exposure going after production stops
The regulatory picture — worldwide
HBCD is one of the clearer regulatory success-in-progress stories: identified as a POP, listed for elimination, and phased down — but with a long persistence tail.
Stockholm Convention — global elimination. HBCD was added to Annex A (elimination) of the Stockholm Convention in 2013, committing parties to phase out its production and use, with only a time-limited exemption for EPS/XPS building insulation. Regulatory — Stockholm Convention on POPs, HBCD Annex A (2013)
European Union — REACH authorisation. HBCD was among the first substances placed on the REACH Authorisation List (Annex XIV) as a Substance of Very High Concern, requiring authorisation for continued use and effectively ending most EU applications. Regulatory — EU REACH Annex XIV (Authorisation List), HBCD as SVHC (PBT)
United States. HBCD has been the subject of EPA risk evaluation under TSCA and is flagged for risk management as a persistent, bioaccumulative substance. Regulatory — US EPA TSCA risk evaluation of HBCD (persistent/bioaccumulative)
The persistence tail. Because HBCD is a POP, the regulatory job is not finished by a ban: it remains in legacy products, building insulation, recycled materials and house dust, so exposure declines slowly even after use stops. Peer-reviewed — Feiteiro et al. 2021 (persistence/bioaccumulation)
What the research says
- Most abundant FR in bedroom dust. Bedding a crucial source; dermal + ingestion routes. Peer-reviewed — Wang et al. 2023
- A Stockholm POP. Persistent, bioaccumulative, toxic; Annex A (2013). Regulatory — Stockholm Convention
- Endocrine & developmental concern. Thyroid/neurodev/repro; EPA "high hazard" developmental. Peer-reviewed — Feiteiro et al. 2021; Barghi et al. 2017
- Toddlers most exposed. Highest estimated body burdens. Peer-reviewed — Barghi et al. 2017
What helps reduce it
Control dust. HEPA vacuuming, damp-dusting and hand-washing before eating cut brominated-FR dust exposure — the main route, and the lever for a legacy POP. Peer-reviewed — Barghi et al. 2017 (dust ingestion a major pathway)
Choose FR-free, recently made furnishings. Newer mattresses and furniture meeting flammability standards without added halogenated FRs avoid HBCD; older treated upholstery is the legacy reservoir. Inferred — HBCD use has been phased out; legacy products are the remaining source
Encase and launder bedding. Since bedding is a documented source, washable covers and regular laundering reduce the bedding-dust contribution. Peer-reviewed — Wang et al. 2023 (bedding a source)
What does NOT help
- Assuming a ban means it's gone. As a POP, HBCD persists in legacy furniture, insulation and dust well after production stops. Regulatory — Stockholm POP persistence
- Air filtration alone. HBCD rides on settled dust and is contacted via bedding; vacuuming and damp-dusting matter more. Inferred
Open research questions
- How fast bedroom HBCD dust declines as treated furnishings age out and are replaced. Speculation
- The developmental significance of low-level early-life HBCD exposure given its thyroid activity. Speculation
- How much recycled polystyrene insulation re-introduces legacy HBCD into homes. Speculation
Citations
- Wang Junchang, et al. (2023). HBCDs and TBBPA in indoor dust from different microenvironments. Environ. Geochem. Health. HBCDs most abundant in bedroom dust; bedding a crucial source; dermal contact with bedding/furniture an exposure route. Via Consensus. Reference record Peer-reviewed
- Feiteiro J, et al. (2021). Health toxicity effects of brominated flame retardants. Environ. Pollut. HBCD in furniture/textiles/electronics; endocrine disruptor; thyroid/neurodev/repro effects; persistent/bioaccumulative. Via Consensus. Reference record Peer-reviewed
- Barghi M, et al. (2017). Human exposure to HBCD and TBBPA via indoor dust in Korea. Sci. Total Environ. HBCD via diet + dust; high toddler body burden; EPA "high hazard" developmental effect. Via Consensus. Reference record Peer-reviewed
- Stockholm Convention on Persistent Organic Pollutants. HBCD listed in Annex A (elimination), 2013; PBT, long-range transport; time-limited EPS/XPS insulation exemption. pops.int Regulatory
Frequently asked questions
What is HBCD?
Hexabromocyclododecane (HBCD) is a brominated flame retardant. Its two big uses are expanded and extruded polystyrene (EPS/XPS) building insulation and the back-coating applied to upholstery and other textiles to make them flame-resistant. That textile back-coating is the bedroom-relevant use: it puts a brominated flame retardant directly into the fabric layer of furniture and some furnishings. HBCD is persistent, builds up in the body and the environment, and is now globally restricted.
Is HBCD a carcinogen?
It is not classified by IARC as a carcinogen, and this page does not claim it is. Its problems are different: HBCD is a persistent organic pollutant — persistent, bioaccumulative and toxic — and it is an endocrine disruptor with documented thyroid, neurodevelopmental and reproductive effects in studies. The US EPA categorises its developmental health effect as "high hazard." So HBCD is a developmental and persistence concern, not a cancer one.
Why does it matter in the bedroom?
Because it migrates out of treated textiles and furniture into house dust, and the bedroom is no exception. In a study of indoor dust, HBCD was actually the most abundant flame retardant measured in bedroom dust, and HBCD levels in bedding dust correlated with room dust — leading the authors to identify bedding as one of the crucial sources of HBCD in the bedroom, alongside dermal contact with bedding and furniture. As with the other brominated retardants, toddlers carry the highest estimated body burdens.
Is HBCD still used?
It is being phased out globally but lingers. HBCD was added to Annex A of the Stockholm Convention in 2013, targeting it for elimination, with only a time-limited exemption for polystyrene building insulation. The EU restricted it under REACH authorisation, and use has fallen. But because it is persistent and was used for decades in furniture, textiles and insulation, it remains widespread in existing products, in house dust and in the environment — so the bedroom exposure is a legacy that decays slowly.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress. This page is informational and is not medical advice.
Last reviewed 2026-06-29. If you find a factual error, contact us.