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Ecotoxicological information

Short-term toxicity to fish

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Link to relevant study record(s)

Description of key information

Eight studies were allocated to this endpoint, with all considered relevant but only the studies of Brosier (1975), Dill  and Emmittee (1980), and Mayes et al. (1978) were considered reliable.   Because the study of Brosier (1975) fulfills the standard 96 hr.freshwater LC50 information requirement, this study is flagged as Key Study and the associated LC50 value of 3.0 mg/L is used for the Chemical Safety Assessment.   The study of Dill and Emmittee (1980) with saltwater sheepshead minnow provides a reliable basis for evaluating sensitivity of saltwater fish to the substance, and is therefore also flagged as Key Study for the marine fish acute LC50 endpoint.

Key value for chemical safety assessment

LC50 for freshwater fish:
3 mg/L
LC50 for marine water fish:
4.6 mg/L

Additional information

The key study was the study of Brosier (1975) reporting the results of a 96-h flow-through acute toxicity test with fathead minnow (Pimephales promelas). The 96-h LC50 was reported to be 3.0 mg/L and will be used in the freshwater aquatic hazard assessment. The study of Mayes et al. (1988) reports an unusual exposure duration of 8 days. Although the fish were fed over the course of this exposure, the extended continuous exposure via flow-through conditions and measured exposure concentrations would tend to result in worst-case conditions for acute lethality. The studies of Dill and Emmittee (1980) were considered of lesser, but acceptable reliabilty because biphenyl concentrations were not measured. Their study of the saltwater fish species (sheepshead minnow) was also deemed reliable, and the resulting 96 hr. LC50 of 4.6 mg/L would indicate that saltwater fish are not apparently more sensitive to the substance than are the several freshwater species tested. The study results summarized by the Ministry of Environment-Japan are included here, and flagged as (currently) unassignable reliability. These results are summarized publically, were commissioned by a government authority for assessment under a separate regulatory program, and were conducted according to OECD guidelines and GLP standards. The resulting 96 hr. LC50 value is in agreement with results summarized for other studies, and application of this value would not result in derivation of a lower PNECaqua in the Chemical Safety Assessment.