Polybrominated+biphenyls


 * __Chemical Formula and Structure of Polybrominated Biphenyls PBB__**

The chemical polubrominated biphenyls or PBB is a colourless to off-white solid often found in plastics. PBB with three or more bromine atoms are solids. PBB is virtually insoluble in water, soluble in fat, and slightly to highly soluble in different organic solvents. PBB is relatively stable and chemicaly unreactive. The chemical formula for PBB is C12H4Br6, and the chemical structure: __**Application**__ PBB is used as a flame retardent in many substances. PBB is added to plastics products such as home electrical appliances, textiles plastic foams,laptops,cabinets, etc. to make them more resistant to burning. PBB stated production in the United States in 1970 appoximately 13.3 million pounds of PBB were produced between 1970 and 1976.

PBB has been proven to be toxic with reseach it has been discovered that animals exposed to PBB had signs of weight loss,skin disorders, nervous system effects,immune system effects, reproductive system effects,spermatogenesis,diseases in children and problems in certain organs such as the liver,kydneys,thyroid glands,and porphyria. Most exposer for humans comes in the form of ingestion,inhilation,and dermal contact. In 1973 PBB was accidently mixed into livestock feed in Michigan. thousands of animals died from this and 12500 residents bought products such as cheese, milk, and meat that was contaminated.
 * __Health Hazards__**

__**Efforts to Stop Manufacturing of PBB**__ Production of PBB still continues even with the risk it presents. PBB has been listed as one of the six controlled substances under the Ristriction of Hazardous Substances Directive (RoHS) since February 2003.

__**Limiting Exposer to PBB**__ Avoid using plastic containers to store food or heat food up. Do not attempt to burn plastics.