An article published on May 23, 2018 in the peer-reviewed journal Environmental Science & Technology addresses environmental risks of medium-chain chlorinated paraffins (MCCPs). The review is authored by Juliane Glüge and colleagues from the Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, ETH Zurich, Switzerland. They focus on MCCPs specifically because both the production and environmental occurrence of this type of chlorinated paraffins are often reported to be much higher than those of the short-chain (SCCP) and the long-chain (LCCP) chlorinated paraffins.
The article provides “a literature overview and a data analysis of the production volumes, PBT properties (persistence, bioaccumulation potential, and toxicity), and the worldwide measured concentrations of MCCP in environmental samples, biota, and humans.” Indeed, CPs of various lengths have been measured not only in wildlife, but also in human blood and placenta. The authors identify China as the “major global producing country” and include “own measurements of technical CP formulations from China . . . to estimate the global production amounts of MCCPs.”
The review’s findings suggest that MCCPs are toxic to the aquatic environment and that they are likely persistent, too. MCPP concentrations in soil, biota, and sediment often show “increasing time trends”. Furthermore, “concentrations in sediment close to local sources exceed toxicity thresholds.” Based on their findings, the authors conclude that “MCCPs are of growing concern, and regulatory actions should be considered seriously.”
CPs of all chain lengths are used as additives in polymeric materials where they can perform several functions, e.g., plasticizing, flame retardancy, or lubricating. A study by Chu Wang and colleagues from the Institute of Environment and Health, Jianghan University, Wuhan, China, published on March 22, 2018 in the peer-reviewed journal Environmental Pollution, measured SCCP and MCCP levels in various domestic products made of plastics and rubber, including 20 food packaging articles. The latter included packaging for chips, cookies, dried fruit, and pies, and were “mainly . . . made with biaxially oriented polypropylene (BOPP) and vacuum metalized PET (VMPET).” SCCPs were “detected in all food packaging, ranging from 14.0-8334 ng/g.” MCPPs “could be detected in most food packaging,” and their concentrations ranged from undetected to 10338 ng/g.
Glüge, J., et al. (2018). “Environmental risks of medium-chain chlorinated paraffins (MCCPs): A review.” Environmental Science & Technology 52: 6743-6760.
Du, X., et al. (2018). “Short-, medium-, and long-chain chlorinated paraffins in wildlife from paddy fields in the Yangtze River delta.” Environmental Science & Technology 52: 1072-1080.
Tong, L., et al. (2017). “High-throughput determination and characterization of short-, medium, and long-chain chlorinated paraffins in human blood.” Environmental Science & Technology 51: 3346-3354.
Wang, Y., et al. (2018). “Distribution and pattern profiles of chlorinated paraffins in human placenta of Henan Province, China.” Environmental Science & Technology Letters 5: 9-13.
Wang, C., et al. (2018). “Concentrations and congener profiles of chlorinated paraffins in domestic polymeric products in China.” Environmental Pollution 238: 326-335.