Overview#
Brominated flame retardants are a class of bromine-based chemicals added to plastics, electronics and textiles to slow ignition. They work well and are cheap, which is why they spread through circuit boards, housings, cables and upholstery. The family includes PBB, PBDE, HBCDD and TBBPA. Each carries its own regulatory history, but they share the same broad concerns.
Why they are a concern#
Three problems recur across the family. They are persistent, so they linger in the environment. They are bioaccumulative, so they build up in living organisms. And when products containing them are burned, they can form brominated dioxins, which are highly toxic. These traits are what pushed regulators to act.
How they are regulated#
The controls are spread across several rules. RoHS restricts PBB and PBDE in electrical and electronic equipment. HBCDD is controlled as a persistent organic pollutant, and TBBPA sits on the REACH Candidate List. So a single flame-retardant additive may fall under different regimes depending on which member it is.
These concerns drive the move to halogen-free electronics, where bromine and chlorine are kept below set thresholds rather than relying on brominated additives.