Polychlorinated biphenyls (PCBs) are a mixture of a series of polychlorinated compounds with different chlorine contents, the main representative of which is C 12H 12L 10. Polychlorinated biphenyls (PCBs) are generally nonflammable, have low conductivity and stable chemical properties, and are difficult to biodegrade except at special high temperatures. They are suitable for some power equipment, hydraulic equipment and heat conduction systems. Used as insulating oil, flame retardant, heat conductive agent, hydraulic oil, plasticizer, pesticide additive, lubricant, cutting oil, sealant and plugging agent, etc. It is also used in railway transformers, mining equipment, carbonless copy paper, pigments, electromagnetic equipment, as micro-lining paper medium and oil-impregnated, optical liquid and natural gas pipeline liquid.
Humans can be affected by PCBs through food pollution. Polychlorinated biphenyls (PCBs) are toxic to fish. Large doses will lead to death, while small doses will lead to failure in spawning, which will also damage the reproductive capacity and immune system of many wild animals. Polychlorinated benzene can also damage human immune system and is listed as a possible carcinogen.