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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to aquatic invertebrates:

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

Toxicity to aquatic plants other than algae:

ErC50 (Lemna minor, 7d, frond number) > 93.1 mg/L (meas. (geom. mean))*

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

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.

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. The study was performed using the concentration of 100 mg/L test item (nominal). For the test concentration, 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.

The treatment showed 10% immobilisationwhich can be stated as not significant. None of the animals was immobilised in the blank control.

Potassium dichromate K2Cr2O7(CAS No. 7778-50-9) was used as positive controlin a current reference study to assure that the test conditions are reliable.

The statistical evaluation program showed that there was no significant difference between treatment and blank control.

At the beginning and at the end of the test, the content of the test item in the test solutions was determined using Photometer-determination. The concentration determined at the start of the test was 99 % of the nominal concentration. At the end of the test the determined concentration was 106 % of the nominal concentration. Therefore, the determination of the biological results was based on the nominal concentration.

The following results were determined :

48h-NOEC100 mg/L (nominal conc.)
48h-LOEC
> 100mg/L (nominal conc.)
24
h-EC50> 100 mg/L(nominal conc.)
48h-EC50> 100 mg/L(nominal conc.)

Toxicity to aquatic plants other than algae

The study was performed in order to evaluate the toxicity of tehe test item towards Lemna minor following the OECD Guideline 221 (2006).The study was performed using 5 concentrations ranging from 1.0 to 100 mg/L (nominal concentration). Incubation time was 7 days. The frond number of each replicate was determined at the beginning, at day 2 and 5 during the test and at the end of the experiment. Additionally, the dry mass of 12 representative fronds was determined at the beginning of the experiment. At the end of the experiment the dry mass of each replicate was determined.

Growth rate µ and the yield were determined from the frond number and the drymass at the respective observation times.

Due to contamination, the lowest concentration was excluded from the evaluation. Although fewer concentrations were taken into account, the statistical significance of the results is still given.

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

The measured concentrations lay between 91 % and 103 % of the nominal concentrations at the beginning of the test and between 65 % and 129 % of the nominal concentrations at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured concentrations (cf. OECD Guideline No. 221 §47). The decrease of the test item could be explained by the inclusion of the test item in the plants. However, this is only an assumption.

The 7d-EC50s of 3,5-Dichlorophenol (1,3-Dichloro-5-hydroxybenzene, C6H4Cl2O, CAS-No. 591-35-5) were determined in a separate reference test. The EC50value of the growth rate lay within the desired range of 1.7 - 5.7 mg/L, mentioned in the paper “OECD Lemna Growth Inhibition Test, Development and ring testing of draft OECD test guideline”, Research and Development Technical Report EMA 003, page 34.

The ErC50 based on frond number for the test item was found to be > 93.1 mg/L  (geom. mean corresponding to nominal concentration of 100 mg/L).

 

JUSTIFICATION FOR CLASSIFICATION OR NON-CLASSIFICATION

According to the CLP Regulation (EC) no. 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 LC50 (for fish) and/or 48 hr EC50 (for crustacea) and/or 72 or 96 hr ErC50 (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 LC50 (for fish) and/or 48 hr EC50 (for crustacea) and/or 72 or 96 hr ErC50 (for algae or other aquatic plants) ≤ 1 mg/L

Category Chronic 2: 96 hr LC50 (for fish) and/or 48 hr EC50 (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 LC50 (for fish) and/or 48 hr EC50 (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) no. 1272/2008.