SOURCES OF PCB EMISSIONS
SOURCE ACTIVITY TITLE:
SOURCES OF POYCHLORINATED BIPHENYLS EMISSIONS N/A N/A
NOSE CODE: NFR CODE: Introduction
This model chapter is aimed at summarizing information relevant to polychlorinated biphenyls emissions for the purposes of their inventory.
1. GENERAL 1.1 Definitions
Polychlorinated biphenyls (PCBs) – a group of synthetic organic chemicals known as chlorinated hydrocarbons which include any chemical substance of the biphenyl molecule that has been chlorinated to varying degrees. The chemical formula for PCBs can be represented as C12H(10-n)Cln, where n is the number of chlorine atoms within the range of 1–10. A total of 209 individual isomers (or "congeners") exist. The term "homologue" is used to refer to all PCBs with the same number of chlorine (e.g. trichlorobiphenyls). Homologues with different substitution patterns are referred to as isomers. For example, dichlorobiphenyl homologue contains 12 isomers. The sum of PCBs may sometimes refer to the sum of seven individual PCB isomers (congeners) called the "Dutch seven". These are commonly reported as ∑PCB7 and includes PCB-28, PCB-52, PCB-101, PCB-118, PCB-138, PCB-153 and PCB-180. For transparency, it is good practice to report the specific isomers referred to when reporting sum PCBs. 1.2 Properties
PCBs have high heat capacity, low conductance, they are inert to acids and alkali, have good solubility in fats, oils and organic solvents, and are explosion-proof. As chlorine content increases, PCBs state of aggregation also changes as well as other properties including their stability in the environment (Table 1.1). With chlorine content from 19 to 43 %, the products have a crystalline form, 43–56 % – oil-shaped, 57–69 % – semisolid and resin-shaped, and from 67 to 70 % - crystalline again.
EMEP/CORINAIR Guidebook
September 2005
BPCB_A-1
SOURCES OF PCB EMISSIONS
Table 1.1 PCBs physical and chemical properties

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