Environmental Risks of Medium-Chain Chlorinated Paraffins (MCCPs): A Review

Abstract

Chlorinated paraffins are industrial chemicals that can be subdivided into short-chain (SCCP), medium-chain (MCCP), and long-chain (LCCP) chlorinated paraffins. The global production volumes of MCCPs are nowadays suspected to be much higher than those of S- and LCCPs, and the few available studies on the environmental occurrence of chlorinated paraffins report often higher MCCP concentrations than S- or LCCP concentrations in the environment. The present review focuses, therefore, on MCCPs specifically and 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. Furthermore, we include our own measurements of technical CP formulations from China, the major global producing country, to estimate the global production amounts of MCCPs. The key findings from this review are that (1) MCCPs are toxic to the aquatic environment, and the available data suggest that they are also persistent; (2) available time trends for MCCPs in soil, biota, and most of the sediment cores show increasing time trends over the last years to decades; and (3) MCCP concentrations in sediment close to local sources exceed toxicity thresholds (i.e., the PNEC). Our study shows that overall, MCCPs are of growing concern, and regulatory actions should be considered seriously.

Evidence for the widespread occurrence of short- and medium-chain chlorinated paraffins in fish collected from the Rhône River basin (France)

“…4430 ng g -1 lw) (Figure 3). Fish collected from the Chéran and Combeauté rivers displayed significantly higher ∑MCCP concentrations than those observed in the Rhône River, but did not exceed a recently proposed PNEC (11 ng g -1 ww whole fish) (Glüge et al, 2018). Such levels are much higher than those reported for lake trout from the Great Lakes (13 -130 ng g -1 lw) (Saborido Basconcillo et al, 2015) or polar cod from Norway (89 ng g -1 lw).…”

“…They have been detected in all environmental compartments, including humans and biota, and they may biomagnify in aquatic ecosystems (Houde et al, 2008a;Huang et al, 2017;Xia et al, 2017;Zhou et al, 2018). SCCPs were listed as Persistent Organic Pollutants and added to Annex A of the Stockholm Convention in 2017 (Glüge et al, 2018). They are expected to be replaced in numerous applications; production and use likely already shifted towards MCCPs prior to this classification .…”

“…They are expected to be replaced in numerous applications; production and use likely already shifted towards MCCPs prior to this classification . The persistence, bioaccumulation potential and toxicity of MCCPs have been less studied and the risk assessment of these chemicals is still ongoing (Glüge et al, 2018). Thus, there is still a need for additional knowledge on the occurrence and fate of CPs in the environment, especially for MCCPs (van Mourik et al, 2016).…”

MCCP: are medium-chain chlorinated paraffins of concern for humans?

“…Known applications of CP are, for instance, the serving as pressure additives in the metal working industry, as plasticizers in the polyvinyl chloride (PVC) production, as additives to rubber, paints and lacquers, adhesive sealants and other polymer material, such as polyurethane, and as lubricants and flame retardants. In 2013, the estimated annual production of MCCP (CAS: 85535-85-9) in China, being the main producer, is 600,000 tons (Gluege et al 2018).…”

Charakterisierung von Chlorparaffinen mithilfe der Kernresonanzspektroskopie (NMR)

“…Die Stoffgruppe der Chlorparaffine (CPs) gehört zu den wichtigsten Umweltkontaminanten der heutigen Zeit [1,2]. Da es sich hierbei stets um hochkomplexe Gemische aus tausenden verschiedenen polychlorierten n-Alkanen unterschiedlicher Kettenlängen und Chlorgehalte handelt, ist die Analytik von CPs sehr herausfordernd [3].…”