3,5-dichlorobenzoyl chloride

Short-term toxicity to aquatic invertebrates

Description of key information

The 48h-EC50 was determined to be >26 mg/L. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

26 mg/L

Additional information

The acute toxicity of the test material to Daphnia magna was determined in a study that was performed under GLP conditions and in accordance with the standardised guidelines OECD 202, EU Method C.2 and the OECD series on testing and assessment number 23. The study has been assigned a reliability score of 1 in line with the principles for assessing data quality as defined by Klimisch et al. (1997).

The test was performed as a combination limit/range-finder. A saturated solution was prepared at a loading rate of 100 mg/L, applying a one-hour period of magnetic stirring and was used as the highest concentration. The lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. The final test solutions were all clear and colourless.

Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to the limit concentration in a limit test. In addition, ten daphnids per group (5 per replicate, duplicate) were exposed to solutions containing 1.0 and 10 % saturated solution in the combined range-finding test. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test.

The test material reacts with water and forms an acidic degradation product. The concentrations of the degradation products were measured and the corresponding concentration of the test material was calculated. The actual concentration of the degradation product measured in the limit concentration, was 24 mg/L at the start of the test and corresponded to 26 mg/L of the test material itself. The measured concentration remained constant during the exposure (98 % of initial at the end of the test). Based on these results, the effect parameters were expressed in terms of measured concentrations.

No immobilisation or other effects were observed in the control and the two lower concentrations during the test. In the limit concentration 40 % of daphnids were affected at the end of the exposure. It can be concluded that based on the results obtained in this study that the EC50 exceeded a measured concentration of 26 mg/L. The study met the acceptability criteria prescribed by the study plan and was considered valid.

Under the conditions of this study, the 48h-EC50 exceeded the measured concentration of 26 mg/L obtained at a loading rate 100 mg/L.