Cracking the (Building) Code on Flame Retardants

Melissa Coffin | September 18, 2014 | Materials

Halogenated flame retardants (HFRs) used in building materials and their breakdown products can be persistent, bioaccumulative, and toxic.  As such, they appear on restriction lists used by many in the green building community, including the Living Building Challenge Red List and the Perkins+Will Precautionary List.   Beyond their environmental or health characteristics, discussion is growing about whether HFRs, or any flame retardant additive, even provide any benefit in a fire in the first place. [1, 2, 3]

While the debate boils over, many US building codes require high resistance to flame even for materials like insulation that are behind thermal barriers and that will have little or no exposure to a fire.  This requires foam insulation manufacturers to add HFRs or other flame retardants to all of their products. [4] Those seeking to avoid these additives can choose inherently flame-retardant insulation, such as fiberglass and mineral fiberboard, but there are currently no options for expanded polystyrene (EPS) and extruded polystyrene (XPS) products in North America that don’t include HFRs.

But, what about in other markets? 

It turns out that several countries, including Sweden and Norway, already have building codes allowing use of plastic foams (EPS, XPS) without flame retardants when in assemblies with a thermal barrier.  In those countries, manufacturers are responding to demand for FR-free foam board.

The Pharos team identified a series of these EPS/XPS foam insulation boards made by three separate manufacturers, that appear not to contain HFRs.  These products are not marketed as “flame retardant free,” but rather reference their conformity to Euroclass F. (See [5] for links to these products in Pharos)

Euroclass is a European Commission standard for the fire performance of building products.  (Foam insulation boards generally require an added flame retardant [6] and attain a Euroclass E rating.)  Products rated Euroclass F are products that have not been submitted for fire performance testing, and although the Euroclass rating system does not explicitly address product content, the Pharos team believes that Euroclass F-rated products are highly likely to be flame retardant-free.

It would seem that, at least with regard to EPS/XPS foam insulations, industry is fully capable of providing flame-retardant free options.  To do so in the US, we must first crack our complex web of building codes.

As it turns out, concerned building owners, academic institutions, public officials, and environmental health organizations are working to do just that.

The Healthy Building Network is an advising partner on the Building Product Ecosystem initiative, which launched publicly yesterday in New York City.   Partners in the BPE include Durst, New School, and CUNY.  These groups are taking a systems thinking approach as they investigate strategies for removing hazardous flame retardants from foam insulation while maintaining fire safe buildings.

And in California, the Green Science Policy Institute has launched the Safer Insulation Solution [7] project to work on California and international codes.   You can join this effort by signing their petition, and promoting it in your community.

With our combined consumer power, we will remove these extreme toxicants from building insulation.



[1] Arlene Blum 2010 Ted Talk, “Plastic Pollution in our Homes,” 6 Nov 2011.  Available

[2] HBO Documentary Fillms, “Toxic Hot Seat” 

[3] Babrauskas V, Blum A, Daley R, Birnbaum L. (2011) Flame retardants in furniture foam: Benefits and risks. Fire Safety Science 10: 265-278.]

[4] Green Science Policy Institute, “Healthy Building” webpage


Polyfoam ECO Roofboard Extra, Knauf:

Polyfoam Eco Floorboard Extra, Knauf:

Polyfoam Eco Floorboard, Knauf:

Floormate 250, 300, and 500 SL-A-N, Dow:

Sundolitt XPS 250/300/400/500/700 SL, Sunde Group:

[6] USEPA "Flame Retardant Alternatives for Hexabromocyclododecane (HBDC) DRAFT (2013). Available

[7] Safer Insulation Solution webpage