Blog Post

Flame Retardant Used in Polystyrene to be Banned by EU

HBCD is used in all polystyrene building insulation--both extruded polystyrene (XPS) and expanded polystyrene (EPS).

Extruded polystyrene, such as this Owens Corning Foamular, is widely used as foundation insulation. The flame retardant used in all polystyrene building insulation is being banned by the European Union.

Photo: Bensonwood

The European Union announced last week that it is banning HBCD (hexabromocyclododecane), the brominated flame retardant used in polystyrene building insulation. The ban will take effect by mid-2015 and be implemented through the European Union's REACH program (Registration, Evaluation, Authorization and Restriction of Chemicals).

HBCD is used in all polystyrene building insulation--both extruded polystyrene (XPS) and expanded polystyrene (EPS). Our newsletter, Environmental Building News, addressed this issue in detail in the August 2009 feature article "Polystyrene Insulation: Does it Belong in a Green Building?" arguing that the health and environmental hazards associated with HBCD are significant enough that we should reevaluate the use of polystyrene until a less hazardous flame retardant is substituted for the HBCD. (There's a summary on the issue that you can access without being a subscriber.) (A later article, "Avoiding the Global Warming Impact of Insulation," in the June 2010 issue of EBN (summary blog here), examined another concern with XPS: that of the high global warming potential of the blowing agent used in this material--but that's another issue.)

The REACH announcement yesterday identifies HBCD as being persistent in the environment, bioaccumulative in biological systems, and toxic (in acronym-speak, it's a PBT). HBCD has been moved from the "candidate list" of chemicals under review to Annex XIV in REACH. Review of the chemical was carried out by the European Chemicals Agency over the past several years. Substances in Annex XIV "cannot be placed on the market or used unless authorization has been granted for specific use." The ban of HBCD will be fully instituted by July 21, 2015--the "sunset date" for the chemical--according to the regulations published in the Official Journal of the European Union on February 17, 2011.

Chemist and EBN Advisory Board member Arlene Blum, Ph.D., a leading expert on health and environmental hazards of halogenated flame retardants, is pleased with the ruling. "HBCD is clearly a bad actor chemical and the EU ban should contribute to its being phased out in the U.S.," she told me.

While REACH regulations include an option for gaining an exemption for particular uses, it doesn't appear that this will happen. According to a statement provided to me by Dow Chemical, "Dow and the industry have been aware of this possibility for many years--well before HBCD was put on the priority list." Considerable investment has been invested in development a next-generation flame retardant for polystyrene insulation. While there is no ready-to-use substitute today, it is very likely that such a replacement will be available by 2015.


BuildingGreen relies on our premium members, not on advertisers. Help make our work possible.

See membership options »

Lots of XPS was used in the Hudson Passive House in New York State: 12 inches under the slab!

The big question for many is whether the replacement flame retardants being considered by the polystyrene industry are halogenated compounds (containing bromine or chlorine). Sticking with a halogenated compound "could mean we're moving from one toxic to another," says Blum. She suggests that we should look at the bigger questions about flame retardants and safety. "It's time to ask what the fire safety benefits of these flame retardants are. In some cases, there is no fire safety benefit." Blum notes that in home furnishings, for example, flame retardants may only delay ignition by a few seconds.

Historically, halogenated compounds have been popular, because they are both efficient at quenching flame spread in burning plastics and relatively affordable, according to an industry expert I spoke with. There are other strategies for controlling the flame spread, however, including intumescent or char-forming agents, which cut the flow of oxygen to the flame, and hydrates that release water vapor to reduce the heat.

While last week's REACH announcement will have significant impact on polystyrene insulation, HBCD isn't the only chemical to be banned. Also included were three phthalate plasticizers that have been widely used in PVC (polyvinyl chloride) products:

  • DEHP (Di(2-ethylhexyl)phthalate) has in the past been widely used in vinyl flooring, though it has largely been removed today.
  • BBP (butyl benzyl phthalate), is used as a PVC plasticizer not only in vinyl tile, food conveyor belts, artificial leather, and other products.
  • DBP (dibutyl phthalate) is used not only with PVC, but also in alkyd resins, nitrocellulose, ethyl cellulose, cellulose plastics, latex adhesives, dyes and chlorobutadiene rubber.

In an increasingly global manufacturing industry, chemical bans through REACH will cascade throughout not only Europe, but also North America. Let's hope that this leads, not just to the swapping of one hazardous chemical for another, but to some fundamentally new chemical engineering.

Alex is founder of BuildingGreen, Inc. To keep up with Alex's latest articles and musings, you can sign up for his Twitter feed.


Published February 22, 2011

Wilson, A. (2011, February 22). Flame Retardant Used in Polystyrene to be Banned by EU. Retrieved from

Add new comment

To post a comment, you need to register for a BuildingGreen Basic membership (free) or login to your existing profile.


November 29, 2011 - 4:22 pm

Ben, I think it's debatable whether the HBCD problem has been solved in an acceptable way. Please see our coverage of the announcement you provided here:

November 28, 2011 - 3:26 pm

I note Dow have forumlated an alternative to HBCD which is neither Persistent, Bioaccumulative, or Toxic. It will be in production before HBCD is phased out. So problem solved in regard to an alternative to HBCD? 

February 22, 2011 - 1:58 pm

Thanks, Alex. I also received a great discussion of this from Tom Lent at Healthy Building Network:

While this is hopefully good news, something I hope doesn't happen, and that you implied and Tom discusses in more detail, is what he terms "regrettable substitutions"--ie will manufacturers switch to another chemical that isn't yet banned but is similarly harmful? Regulations should to be written to avoid these possibilities.

March 2, 2011 - 6:48 am

The idea of coming up with scrubbers for flame retardants is an interesting one, but probably fairly challenging. Halogenated compounds work so well for many applications and are bioaccumulative because they are very stable. While aldehydes can be removed (apparently) relatively easily, I'd be surprised to see such a solution for halogenated compounds, such as HBCD. That isn't a reason not to look for such a solution, just a caution that it will be hard. The priority should be to get those chemicals out of products in the first place.

March 2, 2011 - 5:58 am

Thanks for the article.
For those of us that have already started building with ICF's any suggestions for minimizing the future effects of EPS? Airtight Drywall Approach? I notice CertainTeed has it's "Air Renew Wallboard Absorbs Formaldehyde from Indoor Air " anything similar that would work for the flame retardant chemicals?

February 24, 2011 - 7:38 am

This is great news. At EHDD Architecture we've been debating whether we need to fundamentally rethink how we use rigid insulation in building or whether the presence of HBCD will be "designed" out of products over time. For now we are using mineral wool wherever possible, such as continuous insulation on walls, and investigating its applicability under slabs and roofs. But this announcement is an encouraging sign that change is coming and we can continue to advocate for more highly insulated buildings.