Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity


Fish: LC50 >1000 mg/l


Aquatic invertebrates: EC50 - Daphnia magna >1000 mg/l.


Algae: ErC50 (72 h) >126 mg/l (nominal); NOEC (72 h, growth rate) = 126 mg/l (nominal)


Long-term toxicity


Fish: NOEC (fry length, fry weight) = 4.41 mg/l (TWA, mean measured)


Aquatic invertebrates: NOEC (21d, overall threshold effects) = 1.10 mg/l (nominal)

Additional information

The aquatic toxicity potential of the substance has been evaluated at three trophic levels, including fish, daphnia and algae by considering data on the substance itself.  


Three studies investigating the short-term toxicity to fish are available. In the key study, test was performed according to OECD Guideline 203. The LC50 after 96 hours was determined to be >1000 mg/l. Supporting data from two other studies suggest that the TL50 is >1000 mg/l.  


The acute toxicity of the substance to Daphnia magna was determined in a 48-hour static test according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). In the control and in all test concentrations no immobilization of the daphnids were observed after 48 hours. The EC50 values is greater than 1000 mg /l.


 


The toxicity of the test item to the unicellular freshwater green alga Pseudokirchneriella subcapitata was determined according to the principles of OECD 201 and Council Regulation (EC) No. 266/2016/Method C.3. The study was conducted for 72 hours under static conditions in a limit test at 126 mg/l. The test item was found not to inhibit the growth of the freshwater green alga Pseudokirchneriella subcapitata after 72 hours for growth rate. Effect values were determined as follows (based on nominal test item concentration): The EC50-values for both inhibition of growth rate (ErC50) and yield (EyC50) after 72 hours were >126 mg/l. The NOEC-values for both inhibition of growth rate and yield after 72 hours were 126 mg/l.


The LC50/EC50 of the substance to fish and Daphnia magna was observed to be greater than 1000 mg/l, while for algae it was considered to be >126 mg/l.






 






Regarding long-term studies, a long-term toxicity study on fish and on aquatic invertebrates are available for the analogue substance OB 1 -MSA, performed according to the OECD Guideline 210 and 211, respectively, and under GLP-conditions. A justification for read across is given in section 13 of the IUCLID dossier.


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 effects on reproduction of daphnia were evaluated based on the reproduction per introduced parent animal, since this parameter is the ecologically most relevant response variable and is required by the OECD test guideline 211 (2012), when a significant trend in mortality is detected. The overall effect threshold for effects of the test item on daphnid reproduction under the test conditions was 11.3 mg/l (NOEC) and 22.5 mg/l (LOEC) based on the nominal concentrations of the test item.


 


Considering the available data on the three trophic levels, daphnids are considered to be the most sensitive species as the effect level during the long-term reproductive study was the lowest obtained.


Therefore, the selected NOEC for aquatic toxicity is 1.10 mg/l from the 21-days reproductive Daphnia study on the analogue substance OB 1 -MSA. 


The study conducted on the analogue substance OB 1 -MSA is used for the chemical safety assessment, following a conservative approach. More information on the results of the substances of the category are found on the document attached under "Ecotoxicological information".