Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Aquatic toxicity is discussed. The substance is not considered to be hazardous to aquatic organisms at the limit of solubility in water.

Additional information

Various tests are available to assess the toxicity of the substance to terrestrial organisms. The results of these tests are as follows:

 

OECD Guideline 203 (Fish, Acute Toxicity Test)

Based on the results of the test (given the poor solubility of the test substance in water, the limit test was used), the following value was established:

the highest concentration causing no mortality in fish

Based on the results of the acute toxicity tests in Poecilia reticulata fish(limit test), the following was established for the test substance : the test substance in concentration of <= 100 mg/l (test substance in suspension) dose not cause mortality in Poecilia reticulata during a 96 h test. In accordance with ECHA Guidance document, Chapter R.7b – Endpoint Specific Guidance, “Figure R. 7.8-5: Considerations for difficult substances” the limit value of 100 mg/l is taken as the definitive value for hazard classification purposes.

The substance is not considered to be harmful to fish at the limit if concentration in water. No classification is applicable.

 

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

The test substance n the geometric series of test concentrations – 100 mg.l-1 and less - did not immobilise any Daphnia magna, therefore, the EC(IC)50 at the intervals of 24 and 48 hours could not be established. Based on the test results, an additional value was established:

the highest concentration causing no immobilisation or mortality of Daphnia magna

Based on the results of acute toxicity tests with Daphnia magna (limit test), it was established for the test substance that the test substance  in concentration of <= 100 mg.l-1 (test substance in suspension) does not cause immobilisation of any Daphnia magna. In accordance with ECHA Guidance document, Chapter R.7b – Endpoint Specific Guidance, “Figure R. 7.8-5: Considerations for difficult substances” the limit value of 100 mg/l is taken as the definitive value for hazard classification purposes.

The substance is not considered to be harmful to Daphnia at the limit if concentration in water. No classification is applicable.

 

 OECD Guideline 211 (Daphnia magna Reproduction Test)

The cladoceran, Daphnia magna, was exposed to the test substance at mean measured concentrations of 1.9, 4.5, 11.4, 21 and 38 μg a.i/L under flow-through conditions for 21 days. There were no significant treatment-related effects on survival, reproduction or growth at concentrations ≤38 μg a.i./L. Consequently, the NOEC, based on growth, was 38 μg a.i./L. The LOEC was >38 μg a.i./L and the MATC was calculated to be >38 μg a.i./L. The 21-day EC50 value for adult immobility was >38 μg a.i./L, the highest concentration tested. The 21-day EC10 and EC50 values for reproduction based on mean number of live neonates produced per reproductive day were both >38 μg a.i./L. The 21-day EC10 value for reproduction based on mean number of live neonates produced per adult at the beginning of the test was 16 μg a.i./L. The 21-day EC50 value for reproduction based on mean number of live neonates produced per adult at the beginning of the test was >38 μg a.i./L.

 

OECD Guideline 201 (Alga, Growth Inhibition Test)

As stated, all conditions of the test were met during the growth inhibition tests conducted on freshwater algae Selenastrum capricornutum. In the tests conducted on all controls (both the controls and ‘control A’s), the algal cell density (number of cells per ml) increased at least 103 x and the growth rate reached µ > 1.54 d-1; at the same time, pH changes did not exceed 1.38 units. Equally, the 72 h EbC(IbC)50 and 72 h ErC(IrC)50 values established for the reference substance - potassium dichromate (K2Cr2O7) comply with the required values, therefore, the results of the growth inhibition tests in freshwater algaeSelenastrum capricornutum can be considered valid.

Given the fact that at test concentrations ≥ 25 mg/l , the test substance gradually separated from the solution during the tests despite the application of an auxiliary substance(acetone p.a.), it can be assumed that the values for the growth inhibition of algae Selenastrum capricornutum for the individual concentrations do not correspond with the actual concentration of the test substance  in the solution, therefore, the 72 h EbC(IbC)50 and 72 h ErC(IrC)50 values may be inaccurate; in any case, the 72 h EbC(IbC)50 and 72 h ErC(IrC)50 values for the test substance  (for all five samples) are > 10 mg/l.

In accordance with ECHA Guidance document, Chapter R.7b – Endpoint Specific Guidance, “Figure R. 7.8-5: Considerations for difficult substances” the limit value of 100 mg/l is taken as the definitive value for hazard classification purposes. The substance is not considered to be harmful to algae at the limit of concentration in water. No classification is applicable.

 

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

The test substance was not completely soluble in test medium at the loading rates initially prepared. Therefore, the test substance – Milli-RO water mixtures were magnetically stirred for a period of approximately 25 hours. Subsequently, synthetic medium, sludge and Milli-RO water were added resulting in the required loading rates. Optimal contact between the test substance and test medium was ensured applying continuous aeration and stirring during the 3-hour exposure period.

The test substance was not toxic to waste water (activated sludge) bacteria at or below a loading rate of 1000 mg/l (NOEC). The EC50 exceeded a loading rate of 1000 mg/l.

 

On the basis of these results it is considered that the test substance does not pose a hazard to aquatic organisms at the limit of solubility in water. No further testing is required to refine risk.