P
PBB (Polybrominated Biphenyls)
Definition
Polybrominated biphenyls (PBBs) are a group of brominated flame retardants historically used in plastics for EEE. PBBs are restricted under RoHS Directive 2011/65/EU at a maximum concentration value of 0.1% (1000 ppm) by weight per homogeneous material. PBBs were phased out of most EEE applications before the introduction of RoHS due to environmental and health concerns. The primary concern is their persistence, bioaccumulation potential, and toxicity (PBT properties). PBBs are assessed together with PBDEs in RoHS technical documentation.
Source
Directive 2011/65/EU, Annex II, Article 4(1); IEC 62321-6:2015 (test method for PBBs and PBDEs).
Practical Explanation (Compliance Context)
PBBs are rarely found in modern EEE supply chains, having been largely replaced before RoHS came into effect. However, manufacturers of products with long supply chains or using recycled materials from older equipment should verify the absence of PBBs. IEC 62321-6 specifies the GC-MS test method for quantifying PBBs and PBDEs in polymers. Supplier declarations for plastics components should explicitly confirm absence of PBBs and PBDEs above 1000 ppm.