Ecotoxic effects of the vehicle solvent dimethyl sulfoxide on Raphidocelis subcapitata, Daphnia magna and Brachionus calyciflorus

International audienceDimethyl sulfoxide (DMSO) is widely used as a vehicle solvent inecotoxicity bioassays.Despite its frequent use, it could be toxic fororganisms at some concentrations. Hence, this study aims toinvestigate the effects of DMSO on the modelorganisms: microalgae Raphidocelis subcapitata, microcrustaceanDaphnia magna, and rotifer Brachionus calyciflorus. DMSO wasapplied to the organisms in concentrations ranging from 0.031%to 4%. For R. subcapitata the lowest observed effectconcentration (LOEC) after 72 h of exposure was 0.125% DMSO.The 50% effective concentration (EC50) was 2.138 ± 0.372%. InD. magna, significant differences in the mobility after 24 h or 48 hof exposure were observed for 1% DMSO being 1.712 ± 0.207%and 1.167 ± 0.220% DMSO the EC50 observed for 24 h and 48 hexposure, respectively. For B. calyciflorus, it was not possible tovalidate the tests performed, as there were insufficient animalsalive in the control conditions at the end of the exposure period.Therefore, we recommended avoiding DMSO as a vehicle inassays using B. calyciflorus, and to use final DMSO concentrationsin an experimental solution not exceeding 0.125% forR. subcapitata and 0.5% for D. magna. Finally, using a maximumof 0.01% DMSO is safe for the organisms tested.The effects of the vehicle solvent dimethyl sulfoxide (DMSO)were investigated in three aquatic model organisms, themicroalgae Raphidocelis subcapitata, the microcrustacean Daphniamagna and the rotifer Brachionus calyciflorus. As a result, negativeeffects on growth rate for the algae population, immobilisation ofdaphnids and inhibition of rotifer reproduction was observedobtaining EC50 close to 1% of DMSO for all these cases