Alpha-hexachlorocyclohexane (alpha-HCH) is a major by-product (65-70%) in the manufacture of lindane (> 99% gamma-HCH). Its solubility in water is low, but it is very soluble in organic solvents such as acetone, chloroform, ...

Polychlorinated biphenyls (PCBs) were discovered before the turn of the century and their usefulness for industry, because of their physical properties, was recognized early. The PCBs have been used commercially, since ...

The term polybrominated biphenyls or polybromobiphenyls (PBBs) refers to a group of halogenated hydrocarbons, formed by substituting hydrogen by bromine in biphenyl. PBBs are not known to occur as natural products. They ...

Pure hexachiorocyclopentadiene (HEX) is a light, lemon-yellow liquid that has a pungent, musty odour. The odour threshold is reported to be 0.0014-0.0016 mg/m3. HEX is highly reactive and volatile at low temperatures. ...

Nickel is a naturally occurring, shiny, light-coloured metal with high electrical and thermal conductivities. It is resistant to corrosion by air, water, and alkalis, but reacts with dilute oxidizing agents.

The PCBs are chlorinated hydrocarbons that are manufactured commercially by the progressive chlorination of biphenyl in the presence of a suitable catalyst (e.g., iron chloride). Depending on the reaction conditions, the ...