Polybrominated biphenyls (PBBs) had been widely produced and used as commercial chemicals including additive brominated flame retardants (BFRs) from 1970 to 2000. PBBs are highly toxic, lipophilic and bioaccumulative organic compounds. Owing to their persistence and semi-volatility, PBBs could transport long distance and thus pose potential risk to global environment and human health. Commercial hexabrominated biphenyls (technical Hexa-BBs) have been listed in the Annex A covered under Stockholm Convention on Persistent Organic Pollutants in 2009 for banning the manufacture and use of technical Hexa-BBs. Thus, the sources, analytical methods and environmental occurrence of PBBs have recently attracted increasing attentions. This paper summarizes the basic physico-chemical properties and toxicity of PBBs. The amounts of technical PBBs produced as commercial chemicals including BFRs in history are also summarized. The release of PBBs during dismantling of E-waste as one of important sources is also discussed. We also suggest that further study should be carried out to investigate if there is unintentional formation and emission of PBBs during industrial thermal processes. The research progress on analytical methods, quality assurance and quality control (QA/QC) used for identification and quantification of PBBs are also reviewed and discussed. The occurrence and profiles of PBBs in various matrices from contamination sites of Michigan accident, E-waste dismantling area, and polar area are also reviewed and discussed.

Contents
1 Introduction
2 Basic physico-chemical properties and toxicity of PBBs
2.1 Basic physico-chemical properties of PBBs
2.2 Toxicity of PBBs
3 Major sources of PBBs
3.1 Manufacture, use and release of PBBs
3.2 Unintentional emissions of PBBs from industrial sources
4 Analytical methods of PBBs
4.1 Sample extraction and purification of PBBs
4.2 Instrumental analytical technique
4.3 Quality assurance and quality control
5 Occurrence of PBBs in various matrices
5.1 Contamination levels of PBBs in samples from PBBs contamination accident area
5.2 Contamination levels of PBBs in samples from E-waste dismantling area
5.3 Contamination levels of PBBs in polar area and other regions
6 Conclusion and outlook