Butyl 2-[[3-[[(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)amino]carbonyl]-2-hydroxy-1-naphthyl]azo]benzoate

Endpoint summary

Description of key information

Studies on PR208

Short-term toxicity to fish

The acute toxicity of the test item to fish (zebrafish) was determined according to OECD-Guideline for Testing of Chemicals No. 203 (1992). As the test item is highly insoluble in water, no suitable method for determination of the test item could be established and no analytical determination was carried out.

In this study the test item did not cause any effects to zebrafish after 96 h when tested a saturated solution with a nominal concentration level of 1.00 mg/L. The LC0 (0 – 96 h) was 1.00 mg/L

 

Short-term toxicity to aquatic invertebrates

In the acute immobilisation test with Daphnia magna (STRAUS) the effect of the saturated solution (100 mg/L; the maximum dissolved concentration of the test item that can be achieved under the test conditions in the test medium, acc. to OECD Series, No. 23 (2000)6) as limit concentration of the test item was determined according to OECD 202 (2004) and EC Directive 92/69/EC Method C.2 (1992).At the limit concentration of 100 mg/L of the submission substance no effects on mobility to Daphnia magna were observed. Neither in the control nor in the treatment replicates were any daphnids immobilized.

EC0 (24 and 48 h) = 100 mg/L nominal concentration

EC50 (24 and 48 h) > 100 mg/L nominal concentration

 

Toxicity to aquatic algae

The toxicity of the test itemto the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD 201.

As the test item is highly insoluble in water, no suitable method for determination of the test item could be established and no analytical determination was carried out. All effect values of the test item are given based on the nominal concentration.

In this study no inhibition on growth of the freshwater green alga Desmodesmus subspicatus was found after 72 hours exposure to the test item. The NOEC for inhibition of specific growth rate and yield after 72 hours was 1.00 mg/L.

 

Toxicity to microorganisms

A Respiration Inhibition Test with activated sludge according to OECD Guideline No. 209 was performed with the test item. No inhibition was observed at the tested limit concentration.

In a respiration inhibition test with activated municipial sludge (OECD 209) the following effect concentration was determined for the substance

EC50 (3h) > 1000 mg/L (nominal concentration)

 

Long-term toxicity to invertebrates

The Daphnia magna Reproduction Test (Semi-Static, 21 d) of the test item was conducted as a limit test with the saturated solution with 1.00 mg/L test item according to OECD 211 (2008).
A specific analytic of the test item was not possible, because the test item is insoluble in water and organic solvents. The results given are based on the nominal concentration of 1.00 mg/L of the test item. At the saturated test item solution with 1.00 mg test item/L no biologically or statistically significant effects were determined. The No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) were as follows:

NOEC :             1.00 mg/L

LOEC  :          > 1.00 mg/L

Read-across to PB25

Toxicity to aquatic algae

The toxicity of the test item to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD 201.

As the test item is highly insoluble in water, no suitable method for determination of the test item could be established and no analytical determination was carried out. All effect values of the test item are given based on the nominal concentration.

In this study no inhibition on growth of the freshwater green alga Desmodesmus subspicatus was found after 72 hours exposure to the test item. The test item caused a slight stimulation on the algae growth. The NOEC for inhibition of specific growth rate and yield after 72 hours was 1.00 mg/L.