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Long-term toxicity to aquatic invertebrates

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In a guideline study, Daphnia magna were exposed to Cereclor S52 (52% chlorinated) at nominal concentrations of 0, 0.0056, 0.01, 0.018, 0.032, 0.056 or 0.1 mg/L in freshwater (under static conditions) for 21 days. LC50 values, based on measured concentrations, varied from >0.065 mg/L at day 3 to 0.025 mg/L at day 21. There was a significant decrease in the number of live offspring and a reduction in parental length at mean measured concentrations of 0.018 mg/l (considered the LOEC for these effects) and above, giving a NOEC of 0.010 mg/L.

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Daphnia magna were exposed to Cereclor S52 (a C14-17 chlorinated paraffin; 52% chlorinated) at nominal concentrations of 0, 0.0056, 0.01, 0.018, 0.032, 0.056 or 0.1 mg/L in freshwater (under static conditions) for 21 days, in a study conducted according to (the old) OECD Guideline 202. The test substance was mixed with 8-14C-labelled chlorinated pentadecane (51% chlorinated) to facilitate measurement of test concentrations. The animals were fed during the test. Significant mortality of the parent Daphnia occurred at nominal concentrations of 0.056 and 0.1 mg/L (80% by 21 days and 100% in 7 days respectively), resulting in LC50 values based on measured concentrations varying from >0.065 mg/L at day 3 to 0.025 mg/L at day 21. There was a significant effect on reproduction (decreased number of live offspring) and parental length was reduced (compared to controls) at, and above, nominal concentrations of 0.032 mg/l (0.018 mg/l mean measured), giving a (mean measured) no-observed-effect concentration (NOEC) of 0.010 mg/l and a lowest-observed-effect concentration (LOEC) of 0.018 mg/l (Thompson et al. 1997).

 

In other studies conducted according to OECD guideline 202, Daphnia were exposed to freshwater (semi-static systems) containing dilutions of saturated solutions of C14 -17 chlorinated paraffins (52% chlorinated), resulting in measured 21-day NOECs of between 4 and 16 µg/L (Frank, 1993; Frank and Steinhauser, 1994; Thompson, 2004; TNO, 1993), and measured 21-day LOECs of between 18 and 32 µg/L (Frank, 1993; Frank and Steinhauser, 1994; Thompson, 2004). The animals were fed during these tests.

 

Mussels (Mytilus edulis) were exposed to a C14 -17 chlorinated paraffin (52% chlorinated) at mean measured concentrations of 0.22 and 3.8 mg/l in natural sea water (salinity 34.0-35.5‰) in a flow-through test system for 60 days. No significant mortality or effects on mean shell length were seen at either concentration. Reduced filtering activity (non-quantitative visual observation) at the higher concentration could have been due to the presence of the undissolved test material (solubility limit for the substance was <3.8 mg/l) rather than a true toxic effect, but the 60-day NOEC for this study is considered as 0.22 mg/L (Madeley and Thompson, 1983).

 

 

References - for those study reports with no ESR drafted - only need to move TNO (1993) to reference list of CSR

Frank U (1993). Ökotoxizität von Chloroparaffinen. Institut für Wasser- Boden und Lufthygiene, 23 November 1993 (cited in EU, 2005).

 

Frank U and Steinhauser FG (1994). Ökotoxizität schwerlöslicher Stoffgemische am Biespiel der Daphnientoxizität von Chlorparaffinen. Vom Wasser 83, 203-211 (cited in EU, 2005).

 

Madeley JR and Thompson RS (1983). Toxicity of chlorinated paraffin to mussels (Mytilus edulis) - 52% chlorination of intermediate chain length n-paraffin. ICI Confidential Report BL/B/2289.

 

Thompson RS (2004). Medium-chain chlorinated paraffin (C14-17, 52% chlorinated): A comparison of acute toxicity toDaphnia magnausing two different carrier solvents and water-accommodated fractions. AstraZeneca Confidential Report, BLS3192/B (cited in EU, 2005).

TNO (1993). Semi-static reproduction test with Chlorparaffin Hoechst 52 flüssig and Daphnia magna (OECD Guideline no 202). TNO Environmental and Energy Research. TNO report IMW-R-93/020 (cited in EU, 2005).