Short- and medium-chain chlorinated paraffins in polyvinyl chloride consumer goods available in the Japanese market

Chlorinated paraffins (CPs), including short-chain CPs (SCCPs) and medium-chain CPs (MCCPs), are hazardous chem-ical additives widely applied as plasticizers and flame retardants in polymers, mainly in polyvinyl chloride (PVC). In 2017, SCCPs were listed under the Stockholm Convention on Persistent Organic Pollutants (POPs). MCCPs were pro-posed for listing as POPs in 2021. SCCPs are also restricted under the Basel Convention, with two tentative low POP content (LPC) limits (100 and 10,000 mg kg-1) for SCCPs in waste. As a signatory Party of both conventions, Japan must ensure their implementation and manage SCCP wastes in environmentally sound ways. Therefore, we aimed to assess the occurrence of SCCPs and MCCPs in PVC consumer goods (n = 87) available in the Japanese market. CPs were detected in 48% of the samples. Regarding positive samples, children's products and toys (1.3-120,000 mg kg-1) were more impacted by SCCPs whereas electrical and electronic cables (1.2-59,000 mg kg-1) and house interior products (3.5-550 mg kg-1) were more impacted by MCCPs. Fourteen and four samples exceeded the LPC limit of 100 and 10,000 mg kg-1 for SCCPs, respectively. Most products were impacted by CP con-tents (<1 % w/w) considerably below those reported as intentional CP uses in PVC. However, 11 samples with total CP contents ranging from 1.3% to 15 % (w/w) might have been impacted by intentional CP use as secondary plasticizer in PVC. Most of the impacted consumer goods available in the Japanese market were manufactured overseas, highlight-ing that only restricting POPs nationally is not enough for thorough implementation of the Basel and Stockholm Con-ventions. Therefore, imported PVC consumer goods, PVC waste and PVC recycling streams need to be monitored as relevant potential sources of SCCPs worldwide, even where the national industry strictly follows the restriction of such chemicals.

Automated summary

CPs, including SCCPs and MCCPs, are widely used hazardous chemical additives in PVC. This study assessed the occurrence of SCCPs and MCCPs in PVC consumer goods in the Japanese market, and found that most impacted products were manufactured overseas.