New Flame Retardant for Polystyrene—Too Much Like the Old?

Dow Global Technologies has announced a new flame retardant for use in polystyrene insulation. Dow hopes the new chemical, a brominated flame-retardant (BFR), will replace HBCD (hexabromocyclododecane), a BFR whose use has come under fire from the European Union for environmental and health reasons (see “Flame Retardant Used in Polystyrene to be Banned by EU,” EBN Feb. 2011). In a March 2011 press release, Dow touts the new BFR as a “more sustainable” replacement for HBCD in extruded polystyrene (XPS) and expanded polystyrene (EPS) foam insulation. Watchdog groups have responded to the news with skepticism.

The Hudson Passive House in New York State used 12 inches of Dow's XPS under the slab. Dow announced plans to replace the flame retardant used in that and other products with a new chemical, about which little is known.

Dow announced a license agreement for the unnamed chemical with Great Lakes Solutions, a Chemtura company, which plans to produce and sell it. Dow will license with other producers by the end of 2011, with significant commercial volumes in production by 2015. Although the companies aren’t releasing the chemical’s name, Keith Hughes, director of sales for Great Lakes Solutions, told EBN that the chemical is a brominated, high-molecular-weight butadiene styrene copolymer.

Robert Campbell, director of regulatory affairs for Chemtura, noted that the polymer base has been used in rubber, and that “the bigger the chemical molecule, the tougher it is to be absorbed and have an impact on some kind of biological system—human, animal, or other.” According to Campbell, the companies view the chemical as “pretty inert and innocuous” compared with HBCD. The chemical decomposes when heated, but according to Dow representatives, the chemical, as well as any chemicals generated in its decomposition, is not persistent, bioaccumulative, or toxic (PBT).

Tom Lent, of the nonprofit Healthy Building Network, told EBN, “I’m skeptical of the safety of another brominated molecule to replace HBCD. The history of that class of chemicals is not good. But with no reference to the allegedly ‘extensive and robust environment, health & safety testing regimen and evaluation,’” mentioned in Dow’s press release, he said, “there is no basis on which to evaluate the Dow claims.” Arlene Blum, Ph.D., founder and executive director of the Green Science Policy Institute, echoed these concerns, adding that since the chemical is brominated, “it will burn to produce highly toxic brominated dioxins.”

EBN found additional cause for concern. A 2008 study published in Environmental Science & Technology, found that the type of BFR going into production releases brominated volatile organic compounds (VOCs) when heated, several of which, according to the study, have a “high potential” to be environmentally persistent, and that further testing is needed.

Dow, however, sees brominated chemistry as its future in this area. Chris Bloom, an environmental, health, and safety manager with Dow added, “during the course of this project all possible technologies and options were tested, including halogenated and non-halogenated chemicals.” This chemical is, he said, the “optimal solution, taking into consideration the environmental health profile, the technical efficacy, and processability.”

The use of the chemical was subject to approval by the U.S. Environmental Protection Agency (EPA). Campbell told EBN that EPA “did not identify any concerns which required additional testing or verification.” According to Dow and Chemtura representatives, the testing followed Organization for Economic Co-Operation and Development (OECD) guidelines and met with EPA data quality standards. Bloom told EBN the BFR was not found to be a mutagen or endocrine disruptor, and that no independent or third-party testing is planned. The companies didn’t disclose further testing details.

“I would expect some folks aren’t going to be satisfied with this product,” Campbell said, “but I think from a health and safety perspective, if you look at this product as a chemical itself, this is a great step forward and we think provides a sustainable alternative to HBCD.”

– Emily Catacchio

For more information:

Dow Global Technologies LLC

www.dow.com

Chemtura Corporation

www.chemtura.com

April 5, 2011

DISCUSSIONS