Nonanoic acid

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Data waiving:

other justification

Justification for data waiving:

other:

Description of key information

According to Annex IX of Regulation (EC) No 1907/2006 (Section 9.1, column 2),  long-term toxicity testing on fish shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. The results of the environmental exposure and risk assessment indicate that all RCR <1, which don´t indicate any need to further assess long-term fish toxicity. A supporting study on reproductive effects during a one-month exposure to pelargonic acid showed no relevant effects on key reproductive paramters (see IUCLID section "Additional Information" below).

Additional information

In a one month semi-static (daily renewal) study on Danio rerio reproductive parameters (Techer et al., 2017; published) performed at three exposure concentrations (0.05, 0.5 and 5 mg/L) of pelargonic acid, histological examination indicated that all fish were reproductively mature, and without any alteration in relative germ cell types. No statistical difference in mean fecundity (average number of eggs per female per successful breeding experiment) between control and treatments could be found. The overall hatching rate was slightly reduced only at the highest exposure concentration (5 mg/L; 26.1% lower compared to control). No significant differences could be found between control and treatments regarding embryonic development malformation rate.

In contrast to these key reproductive parameters, significant decrease in 11-ketotestosterone for males at the exposure concentrations 0.05 and 5 mg/L of test item was observed, while significantly lower levels of 17-ß-estradiol were measured for females exposed to 0.5 mg/L of test item. For vitellogenin, males showed no statistical difference from controls for plasma levels, while female mean vitellogenin concentration was significantly higher compared to control at 5 mg/L pelargonic acid.

Neither dead nor abnormal behaving fish were observed throughout the test, and the fish condition index evaluated at the end of exposure (as a general marker of overall fish health status) showed no differences between control and treatment groups.

The study suffers from missing analytical verification of test item concentrations and insufficient reporting (no details on preparation of treatment concentrations; no details on stock solutions given, concentrations in stock solutions not analysed). Accordingly, the study must be regarded as not reliable (RL 3). However, while there may be fluctuations in exposure concentrations from batch to batch due to the semi-static design, overall it must be assumed that there was significant exposure between 0.05 and 5 mg/L, and the fact that no relevant effects on key reproductive parameters have been observed makes it highly probable, that no adverse effects to fish are to be expected at environmentally relevant concentrations.