Polychlorinated terphenyl
Encyclopedia
Polychlorinated terphenyls (PCTs) are a group of chlorine
derivatives of terphenyl
s. They are chemically related to polychlorinated biphenyl
s and have similar chemical properties. They have very low electrical conductivity, high heat stability, and high resistance to alkalies and strong acids. They are non-flammable and insoluble in water.
Typically produced and used as mixtures with varying degrees of chlorination, PCTs were once used as heat transfer agents in electric transformers, as plasticizer
s, as lubricating oils, and as flame-retardants. Their production and use has been largely phased out due to environmental and safety concerns.
International trade in PCTs is regulated by the Rotterdam Convention
.
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
derivatives of terphenyl
Terphenyl
Terphenyls are a group of closely related aromatic hydrocarbons. Also known as diphenylbenzenes or triphenyls, they consist of a central benzene ring substituted with two phenyl groups. The three isomers are ortho-terphenyl, meta-terphenyl, and para-terphenyl. Commercial grade terphenyl is...
s. They are chemically related to polychlorinated biphenyl
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
s and have similar chemical properties. They have very low electrical conductivity, high heat stability, and high resistance to alkalies and strong acids. They are non-flammable and insoluble in water.
Typically produced and used as mixtures with varying degrees of chlorination, PCTs were once used as heat transfer agents in electric transformers, as plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
s, as lubricating oils, and as flame-retardants. Their production and use has been largely phased out due to environmental and safety concerns.
International trade in PCTs is regulated by the Rotterdam Convention
Rotterdam Convention
The Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade, more commonly known simply as the ', is a multilateral treaty to promote shared responsibilities in relation to importation of hazardous chemicals...
.