Chlorinated paraffin
[CAS# 106232-86-4]

Identification

• Classification: Catalysts and additives >> Plastic rubber additive
• Name: Chlorinated paraffin
• CAS Registry Number: 106232-86-4

Discovery and Applications

Chlorinated paraffins (CPs) refer to complex mixtures of polychlorinated n‑alkanes, with medium‑chain chlorinated paraffins (MCCPs) defined by CAS 106232‑86‑4 typically comprising C₁₄–C₁₇ backbones bearing 40–70 wt% chlorine. These compounds first emerged in industrial use in the 1930s, produced via radical chlorination of purified paraffin fractions. The process releases hydrogen chloride and yields a range of congeners, which are then neutralized and stabilized before use.

MCCPs find applications in flame retardants and plasticizers for products like PVC cables, rubber conveyor belts, sealants, adhesives, paints, and industrial lubricants. Their functionality derives from their flame-resistant properties, low volatility, and lubricity.

Environmental monitoring began in the 1990s when concerns arose over the persistence and bioaccumulation of short‑chain CPs (SCCPs). Numerous studies later confirmed that MCCPs also accumulate in sediments, wildlife, and even human tissues. Their lipophilicity and resistance to biodegradation make them prone to long‑range transport and environmental persistence, particularly in aquatic systems.

Chemical analysis of MCCPs is complex due to the immense number of congeners. Detection typically employs techniques such as GC‑ECNI‑MS and LC‑ESI‑MS, which can resolve carbon‑length and chlorine‑content patterns but not individual isomers. This analytical challenge complicates risk assessment and regulatory oversight.

Regulatory action against CPs has intensified in recent years. SCCPs were added to the Stockholm Convention on Persistent Organic Pollutants in 2018, and some jurisdictions have begun restricting MCCPs as substances of very high concern. Industry is actively seeking alternatives and mitigating releases through containment and recycling measures.

Health and ecotoxicological studies indicate that MCCPs have toxic effects on aquatic organisms and potential carcinogenicity in animals. Industrial hygiene standards emphasize containment, exposure monitoring, and personal protective equipment for workers.

In scientific research, CPs are a focus in environmental chemistry, analytical method development, and epidemiology. Bibliometric analyses show a rapid increase in publications on CPs over the past decade, with China, Sweden, and Canada contributing significantly. Studies include monitoring environmental distribution, human exposure assessments, and development of substitutes.

References


Tomy G T Fisk A T Westmore J B Muir D C G (1998) Environmental chemistry and toxicology of polychlorinated n‑alkanes Rev Environ Contam Toxicol 158 53–128 DOI: 10.1007/978-1-4612-1708-4\_2


Wang X T Xu S Y Wang X K Hu B P Jia H H (2014) Short‑ and medium‑chain chlorinated paraffins in urban soils of Shanghai China Sci Total Environ 490 144–152 DOI: 10.1016/j.scitotenv.2014.04.121


Glüge J Schinkel L Hungerbühler K Cariou R Bogdal C (2018) Environmental risks of medium‑chain chlorinated paraffins MCCPs A review Environ Sci Technol 52 6743–6760 DOI: 10.1021/acs.est.7b06459