V.E. Narke, S.R. Bhonglae, S.N. Shegar4 and U.V. Khisti
Abstract
Freshwater green Alga (Pseudokirchneriella subcapitata) was exposed to Chlorpyrifos 50% EC. At 0.1, 0.2, 0.4, 0.8 and 1.6 mg/l. The % inhibition yield at 72h exposure was 0.15, 29.33, 81.63, 95.08, and 98.95 in 0.1, 0.2, 0.4, 0.8, and 1.6 mg/ l, respectively and the % inhibition of growth rate was 0.06, 6.68, 31.84, 55.61 and 79.12 in 0.1, 0.2, 0.4, 0.8 and 1.6 mg/l, respectively. It has been observed that the EyC50 of Chlorpyrifos 50% EC for a period of 72 h for freshwater algae was 0.2776 mg/l with confidence limits of 0.2342 mg/l to 0.3211 mg/ l. The ErC50 of Chlorpyrifos 50% EC observed for a period of 72 h for freshwater algae was 0.5775 mg/l with confidence limits of 0.4248 mg/l to 0.7301 mg/l. The Chlorpyrifos 50% EC is classified under ââ¬ÅCategory 1ââ¬Â as per the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (OECD 201, 2011). In D. magna in the dose range-finding study Chlorpyrifos 50% EC has been exposed to 0.01, 0.018, 0.032, 0.058, and 0.10 mg/l concentrations as per the dose range-finding study. Twenty Daphnids (5/batch) in 4 batches when exposed for 48 h were found to be immobilized at 0, 0.01, 0.018, 0.032, 0.058, and 0.10 mg/l concentrations. At the end of 48 hours was 0%, 0%, 0%, 30%, 90%, and 100% respectively. The 48 h of exposure EC50 of Chlorpyrifos 50% EC for D. magna was calculated as 0.038 mg/l with fiducial Limits of 0.031 to 0.047 mg/l (OECD 202, 1992).