Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to aquatic invertebrates:

EC50 (Daphnia magna, 48 h) = 48 mg/L (geom. mean of measured conc.)

Toxicity to aquatic plants other than algae:

ErC50 (Lemna minor, 7d) = 141.40 mg/L (geom. mean of measured conc.)

Additional information

The following data were obtained for the Similar Substance 01. It is expected that the Target Substance will present similar aquatic toxicity to Daphnia magna and Lemna minor. Justification for Read Across is given in Section 13 of IUCLID.

Invertebrate acute toxicity

A static test was performed according to the OECD Guideline 202 (2004) and the EU method C.2 of the Regulation EC 440/2008. 5 concentrations were used ranging from 4.6 to 100 mg/L (nominal concentration). For each test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours. After 24 and 48 hours, the immobilised Daphnia were counted.

Potassium dichromate K2Cr2O7was used as positive controlin a current reference study to assure that the test conditions are reliable.

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 concentrations determined at the start of the test were between 45 and 81 % of the nominal concentration. At the end of the test the determined concentrations were between 94 and 108 % of the nominal concentration. Therefore, the determination of the biological results was based on geometric mean of measured concentrations.

All validity criteria were met.

Aquatic Plants toxicity

A 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.

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

The measured concentrations lay between 27 % and 49 % of the nominal concentrations at the beginning of the test and between 23 % and 61 % of the nominal concentrations at the end of the test. At the end of the test the measured concentration of treatment 1 mg/L was lower than the LOQ. Therefore, the determination of the results was based on the geometric mean of the measured. Half the LOQ (0.05 mg/L) of the 7d value was used to calculate the geometric mean of the 1 mg/L treatment.

The measured concentrations were much lower than the nominal concentration. It is very likely that the solubility in STEINBERG medium is lower than the solubility in demineralized water. Due to a strong colour of the stock solution at the concentration 100 mg/L, presence of undissolved test item could not be observed. This can be stated as uncritical for the outcome of the study because in the lower concentrations no undissolved test item was present and also toxicity was observed and the biological results were based on the real measured concentration.

 

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.

Additional tests

An old test on the Target Substance is available: it was performed in accordance with internal procedures of the testing facility (modifizierte routine bioassay method vom 1.11.1974). Unfortunately, the reliability of the data cannot be judged because of the lacking of details about test material and testing procedures and conditions. Data is here reported only for completeness purpose.

LC0 (48 h, Salmo gairdnerii) = 20 mg/L

LC50 (48 h, Salmo gairdnerii) = 32 mg/L

LC100 (48 h, Salmo gairdnerii) = 50 mg/L

REFERENCE: Details in attachemnt.

 

JUSTIFICATION FOR CLASSIFICATION OR NON-CLASSIFICATION

According to the CLP Regulation (EC) No. 1272/2008, Part 4: Environmental Hazards, substances can be classified as hazardous to the aquatic environment when the following criteria are met:

A) Acute (short-term) aquatic hazard Category Acute 1: 96-hour LC50 (fish) and/or 48-hour EC50 (crustacea) and/or 72- or 96-hour ErC50 (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-hour LC50 (fish) and/or 48-hour EC50 (crustacea) and/or 72- or 96-hour ErC50 (algae or other aquatic plants) ≤ 1 mg/l;

- Category Chronic 2: 96-hour LC50 (fish) and/or 48-hour EC50 (crustacea) and/or 72- or 96-hour ErC50 (algae or other aquatic plants)> 1 to ≤10 mg/l;

- Category Chronic 3: 96-hour LC50 (fish) and/or 48-hour EC50 (crustacea) and/or 72- or 96-hour ErC50 (algae or other aquatic plants) > 10 to ≤ 100 mg/l.

 

The substance is not rapidly degradable and the acute short-term test to invertebrates fixed effect levels which meets the criterion for the hazard Category Chronic 3 according to the CLP Regulation (EC) No. 1272/2008.