Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Fish

 

A key study was performed to assess the acute toxicity of the test item to rainbow trout (Oncorhynchus mykiss). The method 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.

 

Due to the low aqueous solubility and complex nature of the test item, the test medium was prepared as a Water Accommodated Fraction (WAF).

 

In accordance with the recommendations of REACH, the test was conducted according to the threshold approach recommended by ECHA. Using this approach the lowest EL50 value from either the algal growth inhibition study or acute toxicity to Daphnia magna study is set as the threshold loading rate and a "limit test" is conducted at this threshold loading rate. If no mortalities are observed this indicates that fish are not the most sensitive species and that the LL50 is greater than the loading threshold rate. The EL50 value obtained from the acute toxicity to Daphnia magna study was the lower of the two applicable EL50 values and hence the test was conducted at a single loading rate of 100 mg/L.

 

Seven fish were exposed to a Water Accommodated Fraction (WAF) of the test item at a single nominal loading rate of 100 mg/L for a period of 96 hours at a temperature of 14 °C to 15 °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 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours.

 

Chemical analysis of the freshly prepared 100 mg/L loading rate WAF test preparations at 0 and 72 hours (fresh) showed measured test concentrations of 0.97 and 0.75 mg/L respectively were obtained. The 24 hour old sample saw an increase in measured concentration from 0 hours to 1.46 mg/L. The duplicate sample for the 24 hour old sample was also analysed and confirmed an increase in the measured concentration to 1.28 mg/L. A decline in measured test concentration was observed at 96 hours to 0.055 mg/L.

 

Given that the toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

 

Exposure of rainbow trout to the test item gave LL50 values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L.

 

Daphnia

 

A key study was performed to assess the acute toxicity of the test item to Daphnia magna. The method 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.

 

Due to the low solubility and complex nature of the test item, for the purposes of the test, the test medium was prepared as a Water Accommodated Fraction (WAF).

 

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to a Water Accommodated Fraction (WAF) of the test item at a nominal loading rate of 100 mg/L for 48 hours at a temperature of approximately 21°C under semi-static test conditions. The number of immobilised Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hours.

 

Chemical analysis of the freshly prepared 100 mg/L loading rate WAF test preparations at 0 and 24 hours (fresh) showed measured test concentrations of 0.058 to1.0 and 0.060 mg/L respectively were obtained. A decline in measured test concentration was observed at 24 and 48 hours after media renewal, to 0.016 mg/L and to less than the limit of quantification (LOQ) of the analytical method, determined to be 0.013 mg/L, respectively indicating that the test item was unstable over the test duration.

 

Given that the toxicity cannot be attributed to a single component or mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

 

Exposure of Daphnia magna to the test item gave EL50 values of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate was 100 mg/L loading rate WAF.

 

Algae

 

A study was performed to assess the effect of the test item on the growth of the green alga Pseudokirchneriella subcapitata. The method 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.

 

Due to the low aqueous solubility and complex nature of the test item, a Water Accommodated Fraction (WAF) was prepared.

 

Following a preliminary range-finding test,Pseudokirchneriella subcapitatawas exposed to Water Accommodated Fractions (WAFs) of the test item over a range of nominal loading rates of 10, 20, 40, 80 and 160 mg/L (three replicates 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 hours showed that measured test concentrations ranged from 0.035 to 0.24 mg/L. A decline in measured concentration was observed at 72 hours to less than the limit of quantification (LOQ) of the analytical method employed, which was determined to be 0.0015 mg/L, indicating that the test item was unstable over the test duration.

 

Given that the toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

 

Exposure of Pseudokirchneriella subcapitata to the test item gave ErL50 (72 h) greater than 160 mg/L loading rate WAF. However, it was not possible to calculate 95 % confidence limits for the ErL50 value as no loading rate tested resulted in greater than 50 % inhibition of growth rate. The No Observed Effect Loading Rate (NOEL) based on growth rate was 40 mg/L loading rate WAF and the Lowest Observed Effect Loading Rate (LOEL) based on growth rate was 80 mg/L loading rate WAF.

 

Exposure of Pseudokirchneriella subcapitata to the test item gave EyL50 (72 h) 150 mg/L loading rate WAF. The No Observed Effect Loading Rate (NOEL) based on yield was 40 mg/L loading rate WAF and the Lowest Observed Effect Loading Rate (LOEL) based on yield was 80 mg/L loading rate WAF.

 

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 was designed to be compatible with OECD Guidelines for Testing of Chemicals (2010) No 209 "Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation).

 

Following a preliminary range-finding test and two initial experiments, activated sewage sludge was exposed to an aqueous dispersion of the test item at concentrations of 125, 250 and 500 mg/L (5 replicates of each) for a period of 3 hours at a temperature of approximately 20 °C with the addition of a synthetic sewage as a respiratory substrate.

 

The effect of the test item on the respiration of activated sewage sludge gave a No Observed Effect Concentration (NOEC) after 3 hours exposure of 125 mg/L. The reference item gave a 3 -hour EC50 value of 7.4 mg/L (95 % confidence limits 5.8 -9.5 mg/L).