One of the most studied of the new FRs is Firemaster 550—a bromine and phosphorous-based compound. Firemaster 550 highlights include: 

  • Used in polyurethane foam products, including seating applications, as an alternative to the now phased out of use BFR, pentaBDE.
  • Widely found to be a common contaminant in household dust
  • People increasingly found to be contaminated with Firemaster 550.
  • Identified as an endocrine disruptor that can interfere with thyroid hormone function and linked in studies with lab rats to weight gain (hence a potential obesogen), early onset of puberty, and cardiovascular and neurological effects at levels relevant to human exposure and lower than the no observable effects level reported by the manufacturer.
  • Separate studies in fish provide evidence of persistence, bioaccumulation, metabolism, and genotoxic effects.
The emerging travails of Firemaster 550 and potentially of other FR compounds highlight the first rule of substitution, asking “is it necessary” in the first place—avoid FRs as much as possible, period. Second, it highlights the need to have toxicity testing on the alternatives to enable understanding of whether it is regrettable substitute or not. And third, be wary of the class of chemicals built on bromine.