Chlorinated paraffins in the technosphere: A review of available information and data gaps demonstrating the need to support the Stockholm Convention implementation

Chlorinated paraffins (CPs) have been produced for a wide range of applications, mostly in open uses, such as metalworking fluids, lubricants, coolants or additives in consumer goods. The production volume is more than one million tonnes requiring control of the lifecycle of these persistent and bioaccumulative chemicals. In May 2017, the Stockholm Convention amended its Annex A to list short chain chlorinated paraffins (SCCPs) as a Persistent Organic Pollutant (POP). Additionally, a limit for the presence of SCCPs in other CP mixtures was set at 1% by weight. CPs can be released to the environment throughout their lifecycle. Therefore, the major objective of this review was to assess and compile information on SCCPs and other CPs regarding their lifecycle in the technosphere to support the Stockholm Convention implementation. A few studies have assessed CP production plants and contamination in the surrounding environments. However, there was no systematic investigation of release routes from production and no assessment of associated landfills, even though these are known major pollution sources at other organochlorine production sites. Some studies have reported that industrial areas, where CPs have likely been used, have elevated levels of CPs in sediments and soil. However, although CPs are largely released when used as metalworking fluids or lubricants, no systematic assessment of releases has been conducted at the thousands of sites where CPs are used in high volumes. Many CPs, mainly medium chain chlorinated paraffins (MCCPs) and SCCPs, are used as additives in the production of consumer goods, resulting in exposure risks. Levels above the European Union regulation for SCCPs of 1500 mg kg−1 and up to approx. 20% are frequently found. The end-of-life management of CP-containing products is difficult since no labelling requirement exists even for products containing SCCPs. The Stockholm Convention prohibits the recycling of SCCP-containing products, which will result in challenges recycling the impacted waste categories. The activities under the Stockholm Convention related to SCCPs, such as the inventory, phase-out, and management of impacted products, provide opportunities to address existing data gaps and challenges. Special attention needs to be given to developing countries with lacking analytical capacity as well as waste management and destruction capacity.