Tris(2-ethylhexyl) benzene-1,2,4-tricarboxylate

Long-term toxicity to fish

Description of key information

Long-term toxicity to fish: NOEC > 9.38 µg/L for Danio rerio (OECD 234)

Additional information

Toxicity to fish has been investigated in 14 day test according to OECD Test Guideline No. 204. It is recognised that the duration of the OECD TG 204 test is shorter than that currently accepted for investigating long-term toxicity in fish.

A recent OECD 234 Fish Sexual Development Test has been conducted utilising Danio rerio LWT embryos (<12 hours post fertilisation) exposed mean measured concentrations of 0.35, 0.65, 1.37, 2.98 and 9.38 µg/L. Mean hatch success, time to last hatch, post-hatch survival and cumulative survival (pre- and post-hatch) in the solvent control was 96%, 4.0 days, 91% and 87%, respectively. There was no effect of exposure to TOTM on survival or time to hatch.  Statistical analysis indicated an apparent effect of TOTM (at concentrations of 0.35, 0.65 and 1.37 µg/L) exposure on post-hatch survival (and cumulative survival).  However, a negative trend between concentration and survival was not observed, and survival in the higher concentrations (2.98 and 9.38 µg TOTM/L) was comparable to that observed in the controls indicating that TOTM exposure does not impact fish survival. Mean wet weights and total body lengths, at 60 days post hatch, were 80.3 mg and 17.8 mm, respectively, for the solvent control. Statistical analysis indicated an apparent effect of TOTM on fish body size at 60 days post hatch in the intermediate exposure group (1.37 µg TOTM/L). However, there was no evidence for a relationship between concentration and magnitude of effect and fish body sizes were comparable in the higher concentrations (2.98 and 9.38 µg TOTM/L) and controls, suggesting that TOTM exposure does not impact fish growth. There was no evidence for an effect of exposure to TOTM on the proportion of male, female, undifferentiated or intersex fish (NOEC >9.38 µg/L).  Mean vitellogenin titres (in the head/tail homogenates) were 412 and 185022 ng/mL for the phenotypic male and female fish respectively.  There was no evidence for an effect of exposure to TOTM on male or female vitellogenin concentrations (NOEC >9.38 µg/L). Thus aqueous exposure of early life stages of zebrafish to concentrations up to 9.38 µg/L does not adversely affect health. There is no evidence for an effect on the endocrine system (as assessed through determinations of phenotypic sex ratio and vitellogenin levels).