Leachates from plastic consumer products – Screening for toxicity with Daphnia magna

Plastic products can contain chemicals that are hazardous to human health and the environment. In this study, it was investigated if various plastic products emit hazardous chemical substances to water. Two leaching methods (batch and diffusion tests) were used and the leachates were tested for acute toxicity to Daphnia magna. Nine out of 32 tested plastic product leachates had Daphnia 48-h EC50s ranging from 5 to 80 g plastic material L−1. For the remaining 23 products no effect on mobility was seen even at the highest test concentrations (70–100 g plastic material L−1). A compact disc (recordable) was the most toxic plastic product, but the toxicity was traced to the silver layer not the polycarbonate plastic material. The other products that displayed toxicity were made of either plasticised PVC (artificial leather, bath tub toy, inflatable bathing ring and table cloth) or polyurethane (artificial leather, floor coating and children’s handbag). While the Toxicity Identification Evaluation (TIE) for compact discs using sodium thiosulfate addition showed that silver was causing the toxicity, the TIE for artificial leathers using C18 cartridges showed that hydrophobic compounds were causing the toxicity. Acute toxicity tests of plastic product leachates were found to be useful for screening purposes for differentiating between toxic and non-toxic products.