Feb. 23 (UPI) -- The polymeric flame retardant PolyFR was developed as an "eco-friendly" substitute for more problematic flame retardants, but new research suggests the compound, commonly used in foam plastic building insulation, could be more harmful than anticipated.
After the once-popular brominated flame retardant hexabromocyclododecane, or HBCD, was banned for being too toxic and persistent, PolyFR became the flame retardant of choice.
PolyFR is also a brominated flame retardant, and equally as persistent as HBCD, but because it is a large molecule polymer, chemical engineers estimated the compound would pose fewer environmental risks.
But while PolyFR starts out big, the polymer can be broken down into smaller, potentially harmful chemicals by ultraviolet light and heat.
In a new paper, published Tuesday in the journal Environmental Science and Technology, scientists argue the widespread adoption of PolyFR is premature, and that more research is needed to understand the polymer's exposure risk.
"Our paper points out a lack of knowledge along the lifecycle of PolyFR and states that more information is needed before such chemicals are widely used," study co-author Arlene Blum, research associate in chemistry at the University of California, Berkeley, told UPI in an email.
PolyFR is made from butadiene and styrene, both known carcinogens. When bromine is added, the compound becomes a brominated flame retardant.
Research involving both humans and mice have found links between brominated flame retardant exposure and a range of health problems, including learning and developmental disorders, hormonal imbalance, infertility and cancer.
"Given their potential for serious health harm to our population, we think more research is needed by the building materials and also the electronics industries about when flame retardants actually provide a fire safety benefit and when their use is driven by their producers," said Blum, who is also executive director of the Green Science Policy Institute.
Until flame retardant chemicals are established as safe and effective, researchers suggest the building materials industry adopt the use of inherently flame-resistant mineral fibers like glass wool or stone wool.
Blum said the story of PolyFR follows a common pattern in industrial chemistry, the replacement of a banned chemical with a similar, yet not well-understood compound. Often, the substitute compound turns out to be equally problematic.
"Changing manufacturing processes can be expensive and difficult," Blum said. "When, after many years of scientific research and advocacy, a chemical of concern is phased out, the most likely substitute will be similar in function, structure and, most unfortunately, toxicity."
"You may know that when BPA with phased out, the common and regrettable substitute was BPS," she said. "When the long chain PFAS were phased out, the substitutes were short chains with similar function, structure persistence and toxicity."