Polystyrene's Track Record

Your recent article “Polystyrene Insulation: Does It Belong in a Green Building?” (see

EBN Aug. 2009) misleads readers on several important facts regarding polystyrene foam insulation. Particularly troublesome was the absence of prevailing scientific viewpoints on the safety and environmental attributes of these products.

The article reports that very small amounts of the flame retardant HBCD are used in polystyrene foam insulation. But

EBN fails to inform readers that HBCD is retained in the insulation’s polymer matrix throughout the service life of the product and is, therefore, highly unlikely to cause significant environmental or consumer exposure. A recent risk assessment by the Swedish Chemicals Agency (Kemi) conducted on behalf of the European Union (EU) reports that 86% of HBCD emissions to the environment are related to its use in other products—not polystyrene foam insulation. This is particularly important as the majority of studies cited by

EBN address the chemical HBCD without considering its use in specific products or the means by which specific products can release HBCD into the environment.

Your description of how HBCD may fare under REACH also failed to note that HBCD could in fact be “authorized” for continued use in polystyrene foam insulation, especially considering the low likelihood of exposure from this application and the significant energy-efficiency benefits provided. In any event, until the assessment process is complete, it is premature and patently unfair to advise against the use of a product that uses, but may not result in meaningful exposure to, a particular chemical.

Although the article implies otherwise, HBCD is in fact not currently classified as a POP, and polystyrene foam insulation meets the IBC’s and IRC’s class A designation for flame spread and smoke development.

Your readers should know that polystyrene foam insulation can make a significant contribution to the energy efficiency of homes and buildings, helping to minimize the burning of fossil fuels and reduce greenhouse gas emissions associated with heating and cooling. Polystyrene foam insulation is chemically resistant, non-fibrous and non-irritating, and does not require the use of binders. Polystyrene foam insulation remains an outstanding choice for many building applications, and it most definitely and appropriately belongs in green buildings.

Steve Russell, Vice President, Plastics, American Chemistry Council

Editors’ response:

We regret the error about HBCD being classified as a persistent organic pollutant (POP). As noted in the correction last month, HBCD is currently under review for POP classification, but that process is not complete.

Published September 25, 2009

Steve, R. (2009, September 25). Polystyrene's Track Record. Retrieved from https://www.buildinggreen.com/editorial/polystyrenes-track-record

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September 29, 2009 - 4:50 pm

In the October Letters (see EBN Oct 2009), the American Chemistry Council (ACC) attempts to downplay the placement of HBCD in the REACH Substance of Very High Concern (SVHC) category. This placement, however, is not done lightly by the European Union. HBCD has been placed in a very small select group of substances due to its “hazardous properties of very high concern”. Only 20 chemicals have been selected for this group to date. The ACC suggests that they may avoid REACH restrictions on polystyrene insulation by asserting a low likelihood of exposure asserting that it is retained in the polymer matrix. Yet they also acknowledge that Kemi has found that fully 14% of all human exposure is from this application alone. Furthermore, the “adequate control route” for REACH authorization appropriately does not apply for substances with persistent bioaccumulative toxic (PBT) properties so will not be applicable to HBCD.

That does not mean that HBCD cannot receive authorization for limited uses under REACH but that it will be subject to significant analysis. They must determine if the socio-economic benefits outweigh the risks and find no suitable alternative substances or technologies. Even if it meets these criteria, the Authorization will only be for a limited time and with a plan in place to develop alternatives. (http://guidance.echa.europa.eu/authorisation_en.htm)

Given the seriousness of the hazards posed by a PBT like HBCD, its identification as an SVHC is sufficient to make it eminently responsible to encourage the use of alternatives where possible immediately, regardless of the results of any future temporary authorization. It also is important to begin to look at the other sources of HBCD exposure and explore avoidance alternatives for those applications as well

Tom Lent, Policy Director
Healthy Building Network