Daphnia magna (a planktonic crustacean) were tested, 24 h-EC50 of 50 mg/L was found. The toxic effects were attributed to HCl formation, as benzotrichloride dissociates rapidly into the far less toxic benzoic acid and HCl on water exposure. Compensating the pH decrease in water from the HCl negated toxic effects, suggesting that water acidification is the reason for the low aquatic life toxicity. Benzoic acid has an EC50 of >100 mg/L towards aquatic life, is readily biodegradable and does not accumulate, so is not regarded as toxic towards aquatic life.