Registration Dossier

Diss Factsheets

Ecotoxicological information

Long-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

NOEC (fry length) < 0.625 mg/l (nominal)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish
Effect concentration:
0.625 mg/L

Additional information

The toxic potential of the subsatnce on fish after a long-term exposure was evaluated by consdering data on the substance 5 -A and on the similar substance 2 -A. Justification for Read Across is given in Section 13 of IUCLID.

The effects of 5 -A on the early-life stage of fish (Danio rerio / Zebrafish) were determined according to OECD Guideline 210. Based on the results of a range finding test the test was conducted as an extended Limit test with the nominal test item concentrations 1.25 and 12.5 mg/l. The test was started by placing fertilized eggs into the test vessels and it lasted 36 days (30 days post-hatch). 80 eggs of Danio rerio / zebrafish were exposed to each test concentration, the solvent control and the control (4 replicates with 20 eggs each). The water quality parameters pH-value, oxygen concentration, temperature and total hardness were within the acceptable limits. On study day 6, 90% of the control and 89% of the solvent control larvae had hatched. Therefore, study day 6 was defined as post hatch day 0 (= PHD 0). Different toxicological endpoints were determined: hatching success, fry growth (assessed via length and fresh weight measurements on PHD 30), morphological and behavioral effects, posthatch survival and overall survival. Specific analysis of various concentrations of the test item in the test media and the controls was carried out via HPLC-DAD. The measured concentrations of replicates and test media on study days 0 to 35 were in the range of 94 to 108% of the nominal concentrations in the nominal test item concentration 12.5 mg/l and 1.25 mg/l. Since the measured concentrations were in the range of ± 20% of the nominal concentration, the nominal concentrations of the test item were used for the evaluation.

All effect values are given based on the nominal concentrations of the test item. The results of the parameters hatching success, fry growth (expressed as weight and length measurement at PHD 30), post-hatch survival and overall survival were checked for statistically significant differences. No statistically significant difference was detected between the dilution water control and the solvent control for all parameters (hatching success, fry growth expressed as length or weight on PHD 30, post-hatch survival and overall survival).

The test item partly caused significant effects on Zebrafish in an early life stage test, 30 days post hatch when tested with nominal concentrations of 1.25 and 12.5 mg/l. For the parameters hatch, post-hatch survival and overall survival the NOEC was 12.5 mg/l. Therefore, the respective LOECs were determined to be > 12.5 mg/l. For the parameters fry growth (expressed as fresh weight and length) the NOEC was < 1.25 mg/l. Therefore, the LOEC for these parameters was determined to be 1.25 mg/l. All effect values are given based on the nominal concentrations of the test item.

The effects of 2 -A on the early-life stage of fish (Danio rerio / Zebrafish) were determined according to OECD Guideline 210. Based on the results of a range finding test the test was conducted as a dose-response test with the nominal test item concentrations 0.625, 1.25, 2.50, 5.00 and 10.0 mg/l. The test was started by placing fertilized eggs into the test vessels and it lasted 35 days (30 days post-hatch). 80 eggs of Danio rerio / zebrafish were exposed to each test concentration, the solvent control and the control (4 replicates with 20 eggs each). The water quality parameters pH-value, oxygen concentration, temperature and total hardness were within the acceptable limits. On study day 5, 91% of the control and 90% the solvent control larvae had hatched. Therefore, study day 5 was defined as post hatch day 0 (= PHD 0). Different toxicological endpoints were determined: hatching success, fry growth (assessed via length and fresh weight measurements on PHD 30), morphological and behavioral effects, posthatch survival and overall survival. Specific analysis of various concentrations of the substance the test media and the controls was carried out via HPLC-DAD. The test media were sampled and analyzed prior to exposure on days -1 and during the exposure on study days 0, 7, 15, 22 and 28. The measured concentrations of replicates and test media on study days 0 to 28 were in the range of 81 to 104% of the nominal concentrations.

The results of the parameters hatching success, fry growth (expressed as weight and length measurement at PHD 30), post-hatch survival and overall survival were checked for statistically significant differences. No statistically significant difference was detected between the dilution water control and the solvent control for all parameters (hatching success, fry growth expressed as length or weight on PHD 30, post-hatch survival and overall survival). Therefore, both controls were pooled for statistical analysis.

The test item caused significant effects on Zebrafish in an early life stage test, 30 days post hatch. For the parameter hatch, the NOEC was 10.0 mg/l. Therefore, the respective LOEC was determined to be > 10.0 mg/l. For the parameters post hatch survival and overall survival, the NOECs were 1.25 and 2.50 mg/l, respectively. Therefore, the respective LOECs were determined to be 2.50 and 5.00 mg/l. For the parameter fry growth (expressed as length and fresh weight) the NOECs were < 0.625 mg/l (length) and 0.625 mg/l (weight). Therefore, the LOECs for length and weight were determined to be 0.625 and 1.25 mg/l, respectively.

The choice to include also data on the analogue substance is due to the fact that the study conducted on 2 -A showed the lowest effect levels among the category substances regarding the toxic potential to fish.

Following a conservative approach, the results obtained in the long-term toxicity study on fish on the Similar Substance 2-A will be used for the chemical safety assessment.

More details on the results of the other substances in the Category will be provided in the attached document under "Ecotoxicological Information"