Short-chain Chlorinated Paraffins in Biota – Levels and Effects

Short-chain chlorinated paraffins (SCCPs) are highly complex technical mixtures of polychlorinated n-alkanes with carbon-chain lengths from C10-C13 and chlorine content between 49 and 70%. They are produced by chlorination of n-alkanes and do not occur naturally. Because of their physical properties (viscosity, flame resistance) they are used in many different applications, such as lubricant additives, PVC plasticizers and flame retardants in paints, adhesives and sealants. Among the chlorinated paraffin mixtures, SCCPs have the highest potential for release into the environment, because of their higher vapour pressure and water solubility (about 10-100 times higher than for PCBs). SCCPs can reach the environment through production, storage or use, as well as through leeching, runoff and volatilization from contaminated areas. Despite the fact that they are one of the most challenging groups of compounds to quantify and analyze, SCCPs have been detected in biota and humans, as well as a variety of environmental matrices such as sediments and air. SCCPs have also been detected in remote places such as the Arctic (Reth et al., 2006) and dated sediment cores, suggesting long-range atmospheric transport and persistence in the environment. SCCPs have been found to be toxic to aquatic and soil organisms, fish and there is some evidence of carcinogenicity. This paper reviews the current state of knowledge and highlights the need for further research in order to improve future monitoring efforts.