Environmental risk assessment on capsaicin used as active substance for antifouling system on ships

Biodegradation experiments were carried out with capsaicin to evaluate its degradability. The results show that capsaicin was readily biodegradable under aerobic conditions. The values of K. and the calculated bioconcentration factor indicate that capsaicin have a low potential for bioconcentration. The fish acute toxicity tests conducted with Brachydanio redo show LC50 for capsaicin was 5.98 mg L-1. The tests of alga growth inhibition conducted with Selenastrum capricornutum suggest EC50 for capsaicin was 10(-4) mg L-1. The calculated PNEC (Predicted No Effect Concentration) was 4.9 x 10(-4) mg L-1. The average PEC (Predicted Environmental Concentration) for OECD-EU commercial harbor and marina were 3.99 x 10(-6) and 2.49 x 10(-5) mg L-1, respectively. These indicate that the PEC was much less than the PNEC for capsaicin. The low K-P value of capsaicin suggests the data about the risk of capsaicin to sediment organisms can be waived. According to the results from the analysis of the degradation, bioaccumulation, toxicity and accumulation in sediment, it can be concluded that capsaicin used as active substance for antifouling system on ships poses relatively low risk to marine environment. (c) 2013 Elsevier Ltd. All rights reserved.