Registration Dossier

Ecotoxicological information

Long-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Long-term toxicity to fish:
Results of two studies with two analog substances suggest that DIUP will not produce chronic toxicity to fish at or below its maximum attainable water solubility.

Key value for chemical safety assessment

Additional information

The results of two long-term toxicity studies are reported as NOEC values for chronic fish toxicity. The NOEC value from these studies represents the highest concentration tested and measured under the conditions of the study. The results show thatanalogs to DIUP (DIDP and DUP)do not cause toxicity (ExxonMobil, 200; Rhodes et al., 1995).Additionally, the resultscan be used to assess the potential for endocrine disruption in fish.The multi-generation feeding study with Oryzias latipes (Medaka, 284-days)was conducted by adding DIDP to dry flake food at 20 mg/kg. Evaluation of F1 and F2 embryos showed normal development except for a transient decrease in red blood cell pigmentation, which was observed in both the acetone control and DIDP treatment groups. The male to female ratios (3:1) in all groups were similar. Phenotypic gender classification of male and female fish was histopathologically confirmed to be 100% correct. The gonadal and liver somatic indices were not significantly different in the DIDP treated group. There were no statistically significant changes in mortality, fecundity, or egg production in the treatment groups.

I5 summary

The data used to characterize the fish chronic toxicity of di-isoundecyl phthalate (DIUP; CAS #85507-79-5) ester are consistent with the data for several high molecular weight phthalate diesters summarized by Staples et al. (1997). These data show that high molecular weight phthalate diesters do not produce chronic toxicity to fish at or below their maximum attainable water solubliity. The data used to characterize DIUP are for diundecyl phthalate (DUP; CAS #3648-20-2) ester and di-isodecyl phthalate (DIDP; CAS #68515-49-1) ester, which are analogs to DIUP. Results of studies with two analog substances suggest that diisoundecyl phthalate ester will also not produce chronic toxicity to fish at or below its maximum attainable solubility. Both DIUP and DUP contain undecyl alkyl groups. Whereas DUP contains linear undecyl alkyl groups, the alkyl groups in DIUP are branched. DIDP contains isodecyl alkyl groups. Therefore, because of the structural similarity between these substances and the similar biological behavior of high molecular weight phthalate esters in general, data for the analogs can be used to characterize the biological effects of DIUP for this endpoint. The chronic fish dataset includes results for two species of freshwater fish, Oncorhynchus mykiss and Oryzias latipes.

Staples et al. (1997). Aquatic toxicity of eighteen phthalate esters. Environ. Toxicol. Chem. 16(5): 875 -891.