1,2,4-trimethylbenzene

Short-term toxicity to aquatic invertebrates

Description of key information

The  48 hour LC50 for Daphnia magna was experimentally determined to be 3.6 mg/l (Bobra et al, 1983).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.6 mg/L

Additional information

Based on the information available the Bobra et al, 1983 study is considered to be the key study. The study has a reliability rating of 2 because it is a non-GLP; non-guideline study, published in peer reviewed literature with minor restrictions in design and/or reporting but otherwise adequate for assessment. There is otherwise no information in the article to suggest that the data are invalid. The result does not indicate that 1,2,4-trimethylbenzene would meet the criteria for toxic in the PBT assessment. This endpoint would not affect the classification of the 1, 2, 4-trimethylbenzene since the substance is biodegradable and the log Kow is < 4.0.

A supporting study by Abernathy et al, 1986 reports a 24 hr LC50 for Artemia of 12.0 mg/l. A QSAR calculation using the ECOSAR model gives an estimated 48 hr LC50 for Daphnids of 2.4 mg/l.