Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to aquatic invertebrates:

EC50 (48 h, Daphnia magna) > 100 mg/L (nominal)

Toxicity to aquatic plants other than algae:

ErC50 (Lemna minor, 7d, frond number) > 28.13 mg/L (meas. (geom. mean))*

* value of geometric mean of measured concentration corresponds to 100 mg/L nominal concentration

Toxicity to microorganisms:

IC 50 (3 h) >100 mg/L

Additional information

Firstly, it is worth saying that the substance is very water soluble (i.e. > 10 g/L); it has a log Kow lower than 4 (indicating a low potential for bioaccumulation) and is not rapidly degradable.

Results of a fish acute toxicity test performed on the substance are available. However, a reliability cannot be assigned due to the insufficient documentation for assessment. This study demonstrates a LC50 (Oncorhynchus mykiss, 48 h) = 650 mg/L.

Short-term toxicity to aquatic invertebrates

A limit test was conducted to determine the acute toxicity of the test substance to Daphnia magna, according to the OECD Guideline 202 (2004) and the EU method C.2 of the Regulation EC 440/2008. For the test nominal concentration used (100 mg/L) and control group, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.

No toxicity was observed and none of the animals was immobilised in the blank control. A positive control was tested in a current reference study to assure that the test conditions were reliable. At the beginning and at the end of the test, the content of the test item in the test solutions was determined. The measured concentration was 101 % and 112 % of the nominal at the start and at the end respectively. Therefore, the determination of the NOEC / LOEC / ECx was based on the nominal concentrations.

Toxicity to aquatic plants other than algae

The acute toxicity of the test item to aquatic plants was investigated in a 7–day static test to Lemna minor, according to the OECD Guideline 221 (2006). The study was performed using 5 concentrations ranging from 4.6 to 100 mg/L (nominal concentration). The frond number of each replicate was determined at the beginning, at day 3 and 6 during the test and at the end of the experiment. Additionally, the dry mass of each replicate was determined at the beginning and at the end of the experiment. Growth rate µ and the yield were determined from the frond number and the dry mass at the respective observation times.

Plant growth at 4.6 mg/L was biased because these replicates were contaminated. Therefore, this concentration was not used for evaluation. Despite the lack of this treatment, the results can be considered reliable because toxicity was observed only in the highest concentrated treatment.

At the start and at the end of the test, the content of the test item in the test solutions was determined using photometer.

In the treatments 10 – 100 mg/L, the measured concentrations lay between 35 % and 39 % of the nominal concentrations at the beginning of the test and between 15 % and 21 % of the nominal concentrations at the end of the test.Therefore, the determination of the NOEC / LOEC / ECx was based on the geometric mean of the measured concentrations.

No turbidity of the solution occurred either at the beginning or at the end of the test. The reduction of the test item content can be explained by the adsorption of the test item onto the plants. During validation, the test item was stable in test medium without plants.

Toxicity to microorganisms:

The inhibitory effect of the substance on aerobic waste-water bacteria was investigated in a respiration test, according to the OECD Guideline 209 (1984). The oxygen concentration was measured after a contact time of 180 minutes with activated sludge fed with a standard amount of synthetic sewage feed. The test substance showed a slight inhibition (7.5 %) of the respiration rate at a concentration of 100 mg/L.

 

JUSTIFICATION FOR CLASSIFICATION OR NON-CLASSIFICATION

According to the CLP Regulation (EC n. 1272/2008), Part 4: Environmental Hazards, the substances can be classified for hazardous to the aquatic environment when the following criteria are met:

A )Acute (short-term) aquatic hazard Category Acute 1: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) ≤ 1 mg/l.

B) Long-term aquatic hazard (iii) Substances for which adequate chronic toxicity data are not available and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

Category Chronic 1: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC50 (for algae or other aquatic plants) ≤ 1 mg/L

Category Chronic 2: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC50 (for algae or other aquatic plants)> 1 to ≤10 mg/L

Category Chronic 3: 96 hr LC 50 (for fish) and/or 48 hr EC 50 (for crustacea) and/or 72 or 96 hr ErC 50 (for algae or other aquatic plants) > 10 to ≤ 100 mg/L.

The substance is not rapidly degradable and the available acute toxicity test to Daphnia magna and Lemna minor fixed effect levels that do not meet these classification criteria. Therefore, the substance is not classified for aquatic toxicity according to the CLP Regulation (EC 1272/2008).