3-[[2-(2-cyanoethoxy)ethyl][4-[(4-nitrophenyl)azo]phenyl]amino]propiononitrile

Endpoint summary

Description of key information

LC50 (96h) on fish = 1104 mg/l.

EC50 (30 min.) on activated sludge > 450 mg/l.

EC50 (48 h) on daphnia > saturated solution (nominal 5 mg/l).

ErC50 (72 h) on algae > saturated solution (nominal 5 mg/l).

Additional information

Data on Disperse Orange 080 was only available on fish and microorganisms. Therefore, a read across approach was followed to complete the assessment, using data on a structural analogue, i.e. Similar Substance 01. Details on the read across approach are available in section 13.

Disperse Orange 080 is poorly soluble in water, i.e. < 10 mg/l at 20 °C and pH 8.2, and it is not readily biodegradable. The choice of the read-across is further supported by the similar profile of Similar Substance 01, which is not readily biodegradable and has a low water solubility.

In studies on aquatic invertebrates and algae, saturated solution was obtained upon dissolving 5 mg/l test substance, stirring and filtering. The saturated solution was clear and colourless during the exposure period. The measured concentration of the saturated solution was below the LOD of the HPLC-DAD detector.

Fish

The study on fish followed OECD guideline 203. Despite the low solubility, no measured concentrations were reported. Upon a 96 -hour semistatic exposure, LD50 of 1104 mg/l was identified.

Aquatic invertebrates

The acute toxicity to Daphnia magna was determined in a 48-hour static test, according to OECD guideline 202. It was performed as limit test, at the solubility limit of test substance. Immobilisation of daphnids was taken as effect parameter to determine the EC50. Four replicates were tested, each containing 5 daphnids. An EC50 value above the solubility limit was found.

Aquatic algae

The toxicity to aquatic algae was determined in a 96 -hour static test, according to OECD guideline 201. Several dilutions of the saturated solution were tested: 6.25, 12.5, 25, 50 and 100 %. At all dilutions, measured concentrations were below LOD. Effect concentrations were determined in terms of inhibition of growth rate and yield. At the end of the test, E_rC50 > 100 % as nominal concentration of saturated solution was found.

Microorganisms

The potential toxicity of the substance to microorganisms was assessed based OECD guideline 209. At all nominal tested concentrations (10 - 1000 mg/l) no inhibition of respiration rate was noted.

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 aquatic plants.

As for chronic toxicity, in case of lack of chronic data, the toxic potential is identified by appropriate combinations of acute toxicity data and lack of biodegradability. The threshold of classification is 100 mg/l.

In case of poorly soluble substances, the threshold for classification is identified as the solubility limit of the substance.

Based on a LC50 (96h) > 100 mg/l for fish and EC50 values above the saturation limit with aquatic invertebrates and algae, no classification for acute and chronic toxicity was applied according to the CLP Regulation (EC 1272/2008).