New flame retardants need safety assessment

A large variety of flame retardants have been introduced in the USA since the phase out of the polybrominated diphenyl ethers (PBDEs) but their safety for humans has not been properly assessed, say American researchers. Heather Stapleton and colleagues from Duke University NC, Boston University School of Public Health, and the University of California / Green Science Policy Institute used GC/MS and LC/MS to measure flame retardants in samples of polyurethane foam from residential couches in a study reported in Environmental Science and Technology.

They found that the PBDEs dominated in furniture bought before 2005, when the phase out of the PentaDBE product was introduced. Samples bought after this date contained a wider range of flame retardants, the most common being tris(1,3-dichloroisopropyl) phosphate (TDCPP) and components of the Firemaster550 (FM 550) mixture. FM550 contains triphenyl phosphate, a mixture of isopropyl triarylphosphates, and brominated compounds.

The presence of a label, which is required under the furniture flammability standard Technical Bulletin 117 (TB 117) of California, correctly predicted the presence of flame retardants. However, the absence of a label did not always correlate with their absence.

The contents of flame retardants were significantly higher post-2005 than pre-2005. Coupled with the fact that they are expected to leak from the furniture over time, since they are not bound to the foam, this could represent an increased risk to consumers. For instance, TDCPP is a known carcinogen and was found in 50% of the couches examined, so consumers may have an increased risk of cancer from treated furniture.

Due to the larger variety of the flame retardants now in use, including the FM 550 components, the researchers warned that "future studies evaluating human exposure, particularly children’s exposure, to these mixtures of flame retardants in indoor environments are warranted."

The team also decried the lack of publicly available data on the use of flame retardants in consumer products, which would help to establish pathways of human exposure and the associated health risks.