Chlorinated paraffins (CPs) are a complex mixture of polychlorinated n-alkanes and were introduced in the 1930s. The chlorination degree of CPs can vary between 30 and 70%. CPs are subdivided according to their carbon chain length into short chain CPs (SCCPs, C_10-13), medium chain CPs (MCCPs, C_14-17) and long chain CPs (LCCPs, C_>17). Currently, over 200 CP formulations are in use for a wide range of industrial applications, such as flame retardants and plasticisers, and as additives in metal working fluids, in sealants, paints and coatings. SCCPs are classified as persistent and their physical properties (logK_OW 4.4–8, depending on the chlorination degree) imply a high potential for bioaccumulation. Furthermore, CPs are classified as toxic to aquatic organisms, and carcinogenic to rats and mice. SCCPs was categorised in group 2B as possibly carcinogenic to humans from the International Agency for Research on Cancer (IARC). An alkane is an acyclic saturated hydrocarbon. ... 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). ... Flame retardants are materials that inhibit or resist the spread of fire. ... Plasticizers are plastic additives, most commonly phthalates, that give plastics flexibility and durability. ... To bioaccumulate literally means to accumulate in a biological system. ... In pathology, a carcinogen is any substance or agent that promotes cancer. ... Substances, mixtures and exposure circumstances in this list have been classified by the IARC as Group 2B: The agent (mixture) is possibly carcinogenic to humans. ... The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations. ...