Effect of Potassium Dichromate on the Survival and Reproduction of Daphnia magna

An attempt was made to evaluate chronic effect of Potassium dichromate on Daphnia magna, semi-statically. Based on the results of an acute immobilisation study (48 hour EC50), the test item concentrations of 0.03, 0.05, 0.1, 0.2 and 0.4 mg/L of Potassium dichromate was selected for the chronic investigation. During the study, physico-chemical parameters of M4 medium were recorded and maintained within the range as stated in the OECD guideline no.211 and the validity criteria were met during the study. Based on the results, the EC50 of Potassium dichromate (based on % inhibition of reproduction) was determined as 0.19 mg/L with 95% confidence limits of 0.16 0.22 mg/L. The NOEC and LOEC were determined as 0.05 and 0.1 mg/L. Based on number of offspring reproduced, the NOEC and LOEC were determined as 0.03 and 0.05 mg/L, respectively. Based on survival of parental animal, the EC50 of Potassium dichromate was determined as 0.20 mg/L with 95% confidence limits of 0.15 0.24 mg/L. The NOEC and LOEC were determined as 0.1 and 0.2 mg/L, respectively. There is no published data available in the public domain for chronic effect of Potassium dichromate to Daphnia magna. The data on Potassium dichromate is an important prerequisite for test laboratories because it is used as reference test item for acute and reproduction studies to validate the test. Hence, an attempt was made to generate data for the Potassium dichromate under laboratory conditions.