2-[2-[4-[(2-cyanoethyl)methylamino]phenyl]vinyl]-1,3,3-trimethyl-3H-indolium dihydrogen phosphate

Endpoint summary

Description of key information

LC50 (96h) in fish = 266 mg/l

EC50 (48h) in aquatic invertebrates = 37.1 mg/l

EC50 (7d) in aquatic plants other than algae = 7.46 mg/l as for growth rate of frond number and ErC50 = 5.91 mg/l as for growth rate of dry weight.

Additional information

The assessement on acute aquatic toxicity of test substance relies on findings in fish, aquatic invertebrates and aquatic plants.

Fish

In a 48-hour test on fish on the the substance the LC50 of 266 mg/l of active ingredient was observed.

Aquatic invertebrates

Two 24 -hour studies on Daphnia magna were carried out according to OECD guideline 202. An LC50 value of 37.1 mg/l of active ingredient was reported. Despite currently recommended duration for study on daphnia is 48 h, this result gives a qualitative indication of the potential toxicity of the substance.

Aquatic algae

Toxicity to aquatic algae (Scenedesmus subspicatus) was tested following OECD guideline 201 and a 72 -hour result in terms of growth rate was obtained. However, due to the lack of details, the reliability of this result could not be ascertained. In addition, the specific nature of test substance, i.e. a dye, might interfere with the interpretation of test result, generally leading to an overestimation of the toxicity of the substance.

On these bases, such result was only taken as a qualitative indication and used to confirm data obtained under more appropriate condition, i.e. tests on aquatic plants other than algae.

Aquatic plants

The toxicity to Lemna minor was determined in a 7-day static test, according to OECD guideline 221. During the test, measured concentratios were satisfactorily maintained. However, as the highest concentration was 127 % of nominal, geometric means of measured concentrations were used in the assessement. Effect concentrations were determined in terms of inhibition of growth rate and yield of both frond number and dry weight. After a 7-day exposure, E_rC50 = 7.46 mg/l for frond number and E_rC50 = 5.91 mg/l for dry weight were estimated from measured concentrations of active ingredient.

Microorganisms

The toxicity to microorganisms was also studied following OECD guideline 209 and inhibition of respiration rate was seen at all tested concentrations. An EC50 of 104 mg/l was determined, equivalent to ca. 75 mg /l of active ingredient.

Justification for classification or non-classification according to the CLP Regulation (EC 1272/2008)

The threshold of classification of a substance for acute aquatic toxicity is 1 mg/l. This limit is compared with LC50 (96h) for fish, EC50 (48 h) for daphnia and EC50 (72 - 96 h) for algae or other aquatic plants.

The classification process relied on data of toxicity to fish, aquatic invertebrates, i.e. daphnia, and aquatic plants, i.e. lemna.

As for fish, available 96 -hour study showed an LC50 value of 250 mg/l.

As for daphnia, acute immobilisation was seen in 50 % of daphnia exposed for 48 hours at a concentration of 48.9 mg/l.

As for lemna, a 7 -day exposure caused effects on growth rate of frond number and dry weight with E_rC50 = 7.46 mg/l and E_rC50 = 5.91 mg/l, respectively.

No chronic toxicity data is available from long-term studies. In case of lack of chronic data, the potential for chronic toxicity is identified by appropriate combinations of acute toxicity data and lack of biodegradability. Classification is applied as follows:

- category 1 for EC50 and/or LC50 < 1 mg/l

- category 2 for EC50 and/or LC50 = 1 - 10 mg/l

- category 3 for EC50 and/or LC50 = 10 - 100 mg/l.

- safety net or no classification above 100 mg/l.

Based on available results, lemna appeared as the most sensitive species and implied a classification in Category 2 for chronic aquatic toxicity.