Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Fish: Exposure of Rainbow Trout (Oncorhynchus mykiss) to the test item gave LC50 values > 100 mg a.i./L based on the nominal test concentrations. The No Observed Effect Concentration was 100 mg a.i./L (OECD 203 and EU Method C.1).

 

Aquatic invertebrates: Exposure of Daphnia magna to the test item gave EC50 values of greater than 100 mg a.i./L. The No Observed Effect Concentration was 100 mg a.i./L (OECD 202 and EU Method C.2).

 

Algae: Based on growth rate, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 (72h) value of > 100 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L. Based on yield, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 value of 60 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L (OECD 201 and EU Method C.3).

 

Microorganisms: The effect of the test item on the respiration of activated sewage sludge gave a 3-hour EC50 value > 1000 mg ai/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg ai/L. It was considered unnecessary and unrealistic to test at concentrations in excess of 1000 mg ai/L. The reference item gave a 3-Hour EC50 value of 8.1 mg/L, 95% confidence limits 6.3 to 10 mg/L (OECD 209).

Additional information

Fish

A study was performed to assess the acute toxicity of the test item to rainbow trout (Oncorhynchus mykiss). The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No 203, "Fish, Acute Toxicity Test" referenced as Method C.1 of Commission Regulation (EC) No. 440/2008.

 

In accordance with the recommendations of REACH, the test was conducted according to the threshold approach recommended by ECHA. Using this approach, the lowest EC50 value from either the algal growth inhibition study or acute toxicity to Daphnia magna study is set as the threshold concentration and a “Limit test” is conducted at this threshold concentration. If no mortalities are observed this indicates that fish are not the most sensitive species and that the LC50 is greater than the threshold concentration. Therefore, as the EC50 values obtained for both the algal growth inhibition study and the acute toxicity to Daphnia magna study were greater than 100 mg a.i./L, the test was conducted at a single concentration of 100 mg a.i./L to ensure that toxicity was not observed at this concentration. Seven fish were exposed to an aqueous solution of the test item, at a single concentration of 100 mg a.i./L for a period of 96 hours at a temperature of 14 °C under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 1, 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours.

 

Analysis of the test preparations at 0, 24, 72 and 96 hours showed measured test concentrations to be near nominal and so the results are based on nominal test concentrations only. Exposure of Rainbow Trout (Oncorhynchus mykiss) to the test item gave LC50 values based on the nominal test concentrations of greater than 100 mg a.i./L. The No Observed Effect Concentration was 100 mg a.i./L.

Daphnia magna

A key study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

 

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at nominal concentrations of 10, 18, 32, 56 and 100 mg a.i./L for 48 hours at a temperature of 19 °C to 21 °C under static test conditions. The number of immobilised daphnia were recorded after 24 and 48 hours.

 

Analysis of the test preparations at 0 and 48-Hours showed measured test concentrations to range from 96 % to 98 % of nominal concentration and so the results werebased on nominal test concentrations. Exposure of Daphnia magna to the test item gave EC50 values of greater than 100 mg a.i./L. The No Observed Effect Concentration was 100 mg a.i./L.

Algae

A key study was performed to assess the effect of the test item on the growth of the green alga Pseudokirchneriella subcapitata. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test" referenced as Method C.3 of Commission Regulation (EC) 761/2009.

 

Following a preliminary range-finding test, Pseudokirchneriella subcapitata was exposed to an aqueous solution of the test item at concentrations of 1.0, 3.2, 10, 32 and 100 mg active ingredient (ai)/L (three replicate flasks per concentration) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1 °C. Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter Multisizer Particle Counter.

 

Analysis of the test preparations at 0 and 72 hours showed measured test concentrations ranged from 81 % to 108 % of nominal and the results were based on nominal test concentrations only.

Based on growth rate, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 value of > 100 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L. Based on yield, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 value of 60 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L.

Based on growth rate, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 value of > 100 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L. Based on yield, exposure of Pseudokirchneriella subcapitata to the test item gave an EL50 value of 60 mg ai/L. The No Observed Effect Concentration was 10 mg ai/L and the Lowest Observed Effect Concentration was 32 mg ai/L.

Inhibition of sewage sludge microorganisms

A key study was performed to assess the effect of the test item on the respiration of activated sewage sludge. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (2010) No. 209 "Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation)".

 

In an initial range-finding test activated sewage sludge was exposed an aqueous solution of the test item at concentrations of 10, 100 and 1000 mg/L (3 replicates of the 1000 mg/L test concentration) for a period of 3 hours at measured temperatures of approximately 21 °C with the addition of a synthetic sewage as a respiratory substrate. However, the test item supplied contained 41% water therefore a further range-finding test was performed where activated sewage sludge was exposed to an aqueous solution of the test item at concentrations of 10, 100 and 1000 mg active ingredient(ai)/L (3 replicates of the 1000 mg ai/L test concentration) for a period of 3 hours at measured temperatures of approximately 21 °C with the addition of a synthetic sewage as a respiratory substrate. The rate of respiration was determined after 3 hours contact time and compared to data for the control and a reference item, 3,5-dichlorophenol.

The effect of the test item on the respiration of activated sewage sludge gave a 3-Hour EC50 value of greater than 1000 mg ai/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg ai/L. It was considered unnecessary and unrealistic to test at concentrations in excess of 1000 mg ai/L. The reference item gave a 3-Hour EC50 value of 8.1 mg/L, 95% confidence limits 6.3 to 10 mg/L.