Chromate(2-), [5-(diethylamino)-2-[(2-hydroxy-4-nitrophenyl)azo]phenolato(2-)][5-hydroxy-6-[(2-hydroxy-4-nitrophenyl)azo]-1-naphthalenesulfonato(3-)]-, sodium

Endpoint summary

Description of key information

Short-term toxicity to aquatic invertebrates

EC50 = 146 mg/l

 

Toxicity to aquatic plants other than algae

ErC50 = 50 mg/l

Additional information

No studies on the "Aquatic toxicity" are available for the substance in itself.

Nevertheless studies have been conducted with an analogue molecule (Similar Substance 01). Further information are reported in the Read Across justification attached to section 13.

Different available tests may be considered that give information on Aquatic toxicity.

Short-term toxicity to aquatic invertebrates

The acute toxicity of the Similar Substance 01 to Daphnia magna was determined in a 48-hour static test according to the OECD Guideline 202. The study was performed in compliance with the GLP. The nominal concentrations tested were 45, 100 and 220 mg test article/l, a vehicle and a blank control without any addtions. In all test concentrations non alteration of the test substance was observed after 48 hours. During the test the concentrations in the analysed test media were in the range of 87 - 95 % of the nominal values. Therefore, the reported results are related to the actual mean values of the analysed concentrations of the test article in the test medium, measured at the beginning and at the end of the test. No immobilization and abnormal behaviour of the Daphnia was observed in the controls. The EC50 after 48 h was 146 mg/l, the NOEC and EC0 value were determined to be 39 mg/l, the EC100 value is > 203 mg/l.

Toxicity to aquatic plants other than algae

A study was performed to assess the effect of the Similar Substance 01 on the growth of the freshwater plant Lemna minor according to the OECD Guideline No. 221.

Following a preliminary range-finding test, Lemna minor was exposed to an aqueous solution of the test item at nominal concentrations of 1.0, 3.2, 10, 32 and 100 mg active ingredient (a.i.)/l.

The number of fronds in each control and treatment group was recorded on days 0, 3, 5 and 7 along with observations on plant development. 

Chemical analysis of the test preparations on Day 0 (fresh media) showed measured test concentrations to range from 0.90 to 95 mg/l. A slight decline in measured test concentration was observed on Day 7 in the range of 0.46 to 88 mg/l.

Given this decline in measured test concentrations it was considered justifiable to base the results on the geometric mean measured test concentrations in order to give a “worst case” analysis of the data. 

Exposure of Lemna minor to the test item based on the geometric mean measured test concentrations gave the following results: 

The average specific growth rate (frond number) EC50 was 82 mg ai/L.

The average specific growth rate (dry weight) EC50 was 50 mg ai/L.

The yield (frond number) EC50 was 17 mg ai/L.

The yield (dry weight) EC50 was 13 mg ai/L.

The NOEC was 0.64 mg/L and the LOEC was 2.3 mg ai/L.

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 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).

Based on the above results the Lemna study provides the lowest toxicity endpoint and will be used for Classification. Therefore the test substance is Classified as Category Chronic 3.