Disodium 4,4'-bis[(4-anilino-6-methoxy-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulphonate

Endpoint summary

Description of key information

Short-term toxicity on Daphnia magna:

EC50 (48h) > 100 mg/l

Toxicity to aquatic plants other than algae:

ErC50 (7 d) > 187 mg/l

Additional information

Studies of aquatic toxicity on OB 134 were available on fish, aquatic invertebrates, aquatic plants and microorganisms.

OB 134 is soluble in water, i.e. 14.11 g/l at 20 °C and pH 6.78 and it is not ready biodegradable.

Fish

Short-term toxicity studies on fish were carried out and effect levels, in terms of mortality, were recorded. Purity of test samples was between 34 and 80 %. Effects on fish were noted at concentration above 100 mg/l. As no details on test method and procedure was available, this data was only taken as a qualitative indication of low toxicity to fish.

Aquatic invertebrates

Daphnia magna exposed to test substance for 48 hours, according to ISO 6341.

The reliability of the existing data is very low due to the missing information regarding the method, the composition and the results. Therefore, to better assess the ecotoxicological property on the daphnia magna, studies conducted on the family of the target substance were considered (Optical Brightner category):

All the studies conducted on the chemicals of the category showed a very toxicity to invertebrates (EC50 > 100 mg/l).

Based on these consideration the substance is considered to show an EC50 > 100 mg/l

Algae

Toxicity to aquatic algae was assessed in a 72 -hour study, based on ISO 8692; the purity of test sample was ca. 80 %. Inhibitory effects on the growth, in terms of growth rate and biomass, were noted.

Due to its specific nature, this type of test was considered as not adequate to assess the potential toxicity of test substance, due to the influence of colouration of test substance on test outcome. Therefore, this study was disregarded and a study on other aquatic plants was performed.

Aquatic plants other than algae

The growth inhibitory effects of the test substanceto the duckweedLemna minorwere investigated according to test guideline OECD 221, under static conditions over a period of 7 days.

The no observed effect concentrations (NOEC) were calculated to be 187 mg/l test item for both endpoints.

The 7-day E_rC₅₀(based on frond number) of the test substsanceon the duckweed Lemna minor is > 187mg/l. This value is based on the nominal concentration of the test item as a whole.

Microorganisms

The potential toxicity of the substance to microorganisms was assessed using test samples with purity ranging from 34 to 83 %.

No significant inhibition was noted upon exposure up to 300 mg/l. Such results were only taken as a qualitative indication of low toxicity, as no details on procedure and results were available.

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 all species is greater that 100 mg/l therefore the substance is not classified for aquatic toxicity according to the CLP Regulation (EC n. 1272/2008).