3,3'-[[4-[(2-chloro-4-nitrophenyl)azo]phenyl]imino]bis[propiononitrile]

Endpoint summary

Description of key information

Short-term toxicity to aquatic invertebrates:

EC50 (48 h) = 1.08 mg/l

 

Toxicity to aquatic algae and cyanobacteria:

ErL50 > 100 mg/l

 

Short-term toxicity to fish:

LC50 (96 h) > 195 mg/l

Additional information

A test is available for Daphnia magna which gives enough information about the toxicity of the test substance. No test are available for algae because of the high insolubilty of the test substance.

Different test are available that give information about short-term fish toxicity.

 

Short-term toxicity to aquatic invertebrates:

The acute toxicity of the test substance to Daphnia magna was determined in a 48-hour static test according to the OECD Guideline for Testing of Chemicals, Section 2, No. 202, adapted 4 April 84, and EEC Directive 84/449, L 251, Part C 2.The study was performed under Good Laboratory Practice (GLP) conditions in Switzerland. The nominal concentrations tested were 0.058 - 0.10 - 0.18 - 0.32 - 0.58 - 1.0 and 1.8 mg test article /l , and a control without any additions. The reported results are related to the analytical concentrations of the test article. During test duration the test article concentrations in the analysed test media were in the range of 89.0-137.9 % of the nominal values. Therefore, under test conditions the test article was sufficiently stable. In all test concentrations none alteration of the test substance after 48 hours was observed. In the control and in the test concentrations up to 0.34 mg/l no immobilization of the daphnids was observed.

The EC50 value calculated for these test was = 1.08 mg/l after 48 hours.

 

Short-term toxicity to fish:

The short-term toxicity to fish of the test substance was determined according to the OECD Guideline 203 (Fish, Acute Toxicity Test).

Due to the results of a pretest the nominal concentrations for the main test were selected as : 32 / 56 / 100 / 178 and 316 mg test substance/l. The test the concentrations in the analysed test media at the end of the test were decreased to 26.6 % - 86.0 % of the nominal values. Therefore, the reported results are related to the mean analyzed concentrations of the test substance. The LC50 calculated in this experiment for the test substance is more than 195 mg/l.

 

Toxicity to aquatic algae and cyanobacteria:

No information on "toxicity to aquatic algae and cyanobacteria" is available on the Target Substance. However data available on Similar Substance 02 has been taken into account for the assessment. More details about the similarity between the two substances are reported in section 13.

The toxicity of the test substanceto the unicellular freshwater green algaPseudokirchneriella subcapitatawas determined according to the OECD Guideline 201 and EU Method C.3. The studywas conducted under static conditions with an initial cell density of 6839 cells/mL. A saturated solution with a nominal loading of 100 mg test substance/L was prepared with demineralized water 24±1 h prior to the start of the exposure. An appropriate amount of the test substance was weighed out. The saturated solution was stirred for 24 ±1 h (1100 rpm) with a magnetic stirrer. Undissolved particles were removed by membrane filtration. The following filtrate, i.e. the saturated solution was used in the test. The solution was checked via laser beam (Tyndall effect), which was positive. Thereafter the components of the dilution water were added to the saturated solution. The saturated solution and four dilution levels out of the saturated solution were tested in the definitive test in a geometrical series with a dilution factor of 2:6.25 - 12.5 - 25.0 - 50.0 - 100% of the saturated solution. Three replicates were tested for each concentration and six replicates for the control.The test media were clear throughout the test period.The environmental conditionswere within the acceptable limits.The concentration of the test substance was analytically verified via HPLC‑DAD at the start of the exposure of the saturated solution, the dilutions and the control. The recovery rates of the test substance at test start were below the lowest calibration level (LCL). Therefore, all effect values given are based on the nominal test substance loading levels. Under the study conditions,the test substance was found to inhibit the growth of the freshwater green alga Pseudokirchneriella subcapitata after 72 h. However, the % inhibition of growth rate at the highest loading level was only 6% (not significant) and % inhibition of yield was 28%. The following effect values (based on nominal loading levels) were determined based on the results: The 72 h EL50 with 95% confidence intervals for both inhibition of growth rate (ErL50) and yield (EyL50) after 72 h were > 100% (i.e. 100 mg/L) respectively (Volker, 2017).

 

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 (fish toxicity) when the following criteria are met:

A) Acute (short-term) aquatic hazard

Category Acute 1:

96 hr LC 50 (for fish) ≤ 1 mg/l and/or

48 hr EC 50 (for crustacea) ≤ 1 mg/l 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

Category Chronic 1:

96 hr LC 50 (for fish) ≤ 1 mg/l and/or

48 hr EC 50 (for crustacea) ≤ 1 mg/l and/or

72 or 96 hr ErC 50 (for algae or other aquatic plants) ≤ 1 mg/l

and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

Category Chronic 2:

96 hr LC 50 (for fish) > 1 to ≤10 mg/l and/or

48 hr EC 50 (for crustacea) > 1 to ≤10 mg/l and/or

72 or 96 hr ErC 50 (for algae or other aquatic plants) > 1 to ≤10 mg/l (Note 2)

and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

Category Chronic 3:

96 hr LC 50 (for fish) > 10 to ≤ 100 mg/l and/or

48 hr EC 50 (for crustacea) > 10 to ≤ 100 mg/l and/or

72 or 96 hr ErC 50 (for algae or other aquatic plants) > 10 to ≤ 100 mg/l

and the substance is not rapidly degradable and/or the experimentally determined BCF ≥ 500 (or, if absent, the log K ow ≥ 4).

Category Chronic 4

Cases when data do not allow classification under the above criteria but there are nevertheless some grounds for concern. This includes, for example, poorly soluble substances for which no acute toxicity is recorded at levels up to the water solubility (note 4), and which are not rapidly degradable in accordance with section 4.1.2.9.5 and have an experimentally determined BCF ≥ 500 (or, if absent, a log K ow ≥ 4), indicating a potential to bioaccumulate, which will be classified in this category unless other scientific evidence exists showing classification to be unnecessary. Such evidence includes chronic toxicity NOECs > water solubility or > 1 mg/l, or other evidence of rapid degradation in the environment than the ones provided by any of the methods listed in section 4.1.2.9.5.

The EC50 value calculated for the test substance on the "long-term toxicity to aquatic invertebrates" was established to be 1.08 mg/l, therefore the substance is classified as Category Chronic 2 (48 hr EC 50 (for crustacea) > 1 to ≤ 10 mg/l).