In order to understand the potential ecotoxicity of Graphene released into aquatic environment, the toxicities of two types of this material were assessed using two freshwater (Daphnia magna and Danio rerio) and one saltwater (Artemia franciscana) organism. Two types of graphene were tested, including GPX-205 (750 m2/g, <2 micron lateral dimension) and GPX-103 (120-150 m2/g, 25 micron lateral dimension) provided by Cabot corporation. Based on the observations, water suspension of GPX- 205 was very stable, while GPX-103 was not stable in water even after ultrasonication. According to the results, none of the tested substances caused the death of Zebrafish during 96 hours. Although GPX-103 didn’t immobilize Daphnids during 48 hours, 48h-EC50 of GPX-205 was calculated as 17.519 mg/L for Daphnids. Also both materials caused signs of abnormal swimming behavior in Daphnia, especially swimming at the bottom. The 96h-LC50 of GPX-103 and GPX-205 for Artemia was calculated as 7.399 and 1.653 mg/L, respectively. Overall, acute toxicity of GPX-205 was higher than GPX-103; also sensitivity of brine shrimp was higher than water flea. More studies are needed to understand effects of long-term exposure of aquatic organisms to Graphene.
