PBB (PBB)

Polybrominated Biphenyl (PBB) is a family of organobromine compounds consisting of biphenyl molecules with two to ten bromine atoms substituted on the aromatic rings. PBBs were manufactured from the mid-1960s through the late 1970s as flame retardants in thermoplastic housings of TVs and radios, in textiles, and in industrial-machinery polymers. The class includes 209 possible congeners — hexabromobiphenyl (BB-153) was the dominant commercial product (FireMaster BP-6, marketed by Michigan Chemical).

Manufacturing was effectively halted globally after the 1973 Michigan livestock contamination disaster — accidental substitution of PBB for magnesium oxide cattle feed supplement led to PBB accumulation in 1.5 million animals and exposure of an estimated 9 million people through dairy and meat products. By 1979, US production had ceased. The Stockholm Convention on Persistent Organic Pollutants listed hexabromobiphenyl in Annex A in 2009, mandating elimination. The EU's RoHS Directive (2002/95/EC, recast as 2011/65/EU) banned PBBs in any electrical or electronic equipment placed on EU markets above 0.1% by weight per homogeneous material; the restriction is reflected in India's E-Waste (Management) Rules 2022 through the "reduction in use of hazardous substances" provisions.

The recycling consequence is severe. Plastics recovered from pre-1980s consumer electronics, industrial machinery, and certain textile applications may contain PBB above the 0.1% RoHS threshold, and any regranulate produced from these flows is non-recyclable into new consumer-electronics housings. Brominated dust generated during shredding of PBB-bearing polymers is itself a hazardous waste. Detection in incoming feed uses XRF (X-ray fluorescence) handheld guns that screen for total bromine — a positive total-Br above 1,000-2,000 ppm flags suspect material for laboratory GC-MS confirmation; bromine-free plastics are safe to regrind, brominated ones must be diverted to controlled-temperature incineration (above 1,100°C with 2-second residence time and rapid quench) at hazardous-waste TSDFs.

Practically, Indian e-waste recyclers handle PBB risk through generation-based feed segregation. Equipment older than 1985 is assumed to potentially contain PBB and is routed to dedicated brominated-plastic streams; post-2006 equipment is RoHS-compliant by manufacturer declaration and can be safely regrind. The trade-off is that the bulk of legacy e-waste in India arriving today is pre-RoHS-compliance imports from earlier decades — PBB and PBDE screening is mandatory for any plastic regranulate sold into the consumer goods supply chain.