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, C10-13), medium chain CPs (MCCPs, C14-17) 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, as additives in metal working fluids, in sealants, paints and coatings and as a solvent for Dichloramine T. SCCPs are classified as persistent and their physical properties (logKOW 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). A global ban on SCCPs is being considered under the Stockholm Convention POPs convention.
