Short Chain Chlorinated Paraffins : ABSTRACT

The objectives of this assessment are to assess the ecological and human health risks of short-chain chlorinated paraffins (SCCPs), and to conduct an economic evaluation for risk reduction to propose desirable measures.

First, the volume of production, use and releases of SCCPs from each life cycle stage are estimated. Second, the releases estimated are input into the multimedia model of the European Union System for the Evaluation of Substances (EUSES), and the concentrations of SCCPs in environmental media and food are estimated. Third, the SCCP concentrations estimated and those obtained in the actual environmental monitoring were compared to identify contaminated levels of SCCPs in water, sediment and soils, and human daily intake as the exposure data for risk characterization.

On the other hand, toxicity of SCCPs to ecosystem and human health is reviewed and summarized in the hazard assessment. The percentages of species affected by SCCPs among biotic community are estimated, and HC5, a concentration with which 5% of aquatic species are affected, of 2.9 mg/L estimated from species sensitivity distributions (SSD) was derived as the criteria for screening assessment for aquatic organisms. Using equilibrium partitioning, the HC5 for sediment-dwelling and soil-dwelling organisms are derived as 11 and 10 mg/kg-wet, respectively.

Regarding repeated dose toxicity, the NOAEL was established as 100 mg/kg/day with the endpoint of tubular pigmentation in female rats. Regarding reproductive toxicity, the NOAEL for developmental effects in rats was established as 500 mg/kg/day.

Based on the results of exposure and hazard assessments, risk characterization is performed. As a result, it is determined that there are low potential ecological risks to aquatic, sediment-dwelling and soil-dwelling organisms at local and regional levels. Regarding human health risks, the MOEs are 1.5 ´ 105 and 2.2 ´ 106, respectively, which are large enough with consideration of uncertainty factors. Thus, it is determined that there are no significant human health risks of SCCPs.

Based on the results of risk assessment, a voluntary management approach is proposed for the plants using metal working fluids, and the step-by-step procedures of voluntary-management are considered. With the classification of SCCPs into Class I Chemical Substances Monitored, more definitive exposure analyses can be performed in the future.

This SCCPs Risk Assessment Document was produced by the Development of Chemical Substance Risk Assessment and the Risk Assessment Procedure Program by the New Energy and Industrial Technology Development Organization.

The full text of SCCPs Risk Assessment Document (in Japanese) was published by Maruzen Co., Ltd. in September 2005.