Chlorinated paraffins

Chlorinated paraffins ( CPs) and chlorinated paraffins or Chloroparaffine be called. They are prepared by chlorination of n-alkanes, wherein complex mixtures of different chlorinated alkanes formed. The degree of chlorination varies between 30 and 70 %.

CPs are subdivided due to their chain length into short-chain CPs ( SCCPs, short chain CPs, C10 -13, general empirical formula: CxH (2x -y 2) Cly, where x = 10-13 and y = 1-x), medium-chain CPs ( MCCPs, medium chain CPs, C14 -17) and long chain CPs ( LCCPs, long chain CPs C > 17). Chlorinated paraffins are depending on the chain length and chlorine content colorless or yellowish, slightly mobile to highly viscous liquids or glassy to waxy solids. They are resistant to chemicals and light resistant, temperature resistant up to 200 ° C, relatively low volatility and low flammability.

Use

Find application chlorinated paraffins as a plasticizer mainly in plastics and coatings as binders in paints, as an additive in joint sealants, metal processing, oiling agents for leather and fur products, and as a flame retardant in plastics, rubber, paper and textiles.

The flame retardant effect of the CP due to an elimination of non-combustible hydrogen chloride at high temperatures. Additionally disturbing chain termination reactions, the combustion and flame propagation. CPs have taken partly because of their applications the place of polychlorinated biphenyls ( PCBs), which are now banned because of their toxicity.

Main Country of production of chlorinated paraffins is China, where about 600,000 tons were produced in 2007.

Properties

Due to the physical properties of short chain CPs are environmentally hazardous substances with persistence and a high potential for bioaccumulation ( accumulation in adipose tissue, kidney and liver ). CPs are ubiquitous, ie they can demonstrate throughout the world in soil, water, sediments, plants, animals, humans, etc.. They are also very toxic to aquatic organisms and carcinogenic for rats and mice. Short chain CPs have been also as a possible human carcinogen classified by the IARC as a Group 2B. The acute toxicity of chlorinated paraffins is low. The chronic toxicity increases with decreasing carbon chain length.

Ban

The use of short chain CPs in the metalworking industry and in leather processing and finishing was banned in the EU in 2002. Further limitations are examined by the EU at the time. In addition, short-chain chlorinated paraffins have been proposed for inclusion in the Stockholm Convention and are currently being tested by a scientific committee.

Commission Regulation ( EU) No 519/2012 of 19 June 2012 amending Regulation ( EC) No 850/ 2004 of the European Parliament and of the Council on persistent organic pollutants, the use and placing on the market within the EU was banned. Notwithstanding any use of substances and preparations which SCCPs at concentrations of less than 1 percent - contain %, manufactured, marketed and used in traffic.

Swell

• Substance Group
• Chloroalkane