2-[(2-nitrophenyl)amino]ethanol

Toxicity to aquatic algae and cyanobacteria

Description of key information

The substance 2-[(2-nitrophenyl)amino]ethanol was found to inhibit the growth of the freshwater green alga Pseudokirchneriella subcapitata with the following effect values expressed as nominal concentrations (the measured concentrations represents > 80% of the nominal concentrations).

EC50 values for inhibition of specific growth rate (ErC50) and yield (EyC50) after 72 hours of exposure were 79.1 mg/L and 33 mg/L respectively. The ErC10 and NOEC values for inhibition of specific growth were 26.7 and 10 mg/L respectively, and the EyrC10 and NOEC values for yield were 12.6

and 10 mg/L respectively. The most reliable values are considered to be 72h-ErC10 growth rate 26.7 mg/L and the 72h-ErC50 growth rate 79.1 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

79.1 mg/L

EC10 or NOEC for freshwater algae:

26.7 mg/L

Additional information

The toxicity of the substance 2-[(2-nitrophenyl)amino]ethanol to the green algae Pseudokirchneriella subcapitata was tested according to the OECD guideline 201 and EU method C.3, and in conformity with GLP. The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours.

The study was conducted under static conditions. The algae at the initial concentration of 5 E+3 cells/mL were exposed during 72 hours to the following nominal concentrations 0 (control), 0.3, 1, 3.2, 10, 32 and 100 mg/L. The tested concentrations, analysed by High Performance Liquid Chromatography with UV detection, were maintained more than 80% of the nominal concentrations during the exposure. At the start of the test 101% of the nominal test concentrations were found (average of all test concentrations). After 72 hours test duration, 93% of the nominal value were determined (average of all test concentrations). During the test the algae were exposed to a mean of 97% of nominal. Therefore, all reported results refer to nominal concentrations.

All the validity criteria of the guidelines were fulfilled : the pH did not increase more than 1.5 units, the cell density in the controls increased 87.5 fold, the coefficient of variation of average specific growth rates during the whole test period in control replicates was 2.46% and the mean coefficient of variation in growth rate between adjacent time periods was 32.8 % for the control replicates.

EC50 values for inhibition of specific growth rate (ErC50) and yield (EyC50) after 72 hours of exposure were 79.1 mg/L and 33 mg/L respectively. The ErC10 and NOEC values for inhibition of specific growth were 26.7 and 10 mg/L respectively, and the EyrC10 and NOEC values for yield were 12.6 and 10 mg/L respectively.

Since the validity criteria are fulfilled for the growth rates in the controls, the results of the inhibition of the test item on the growth rate are prefered to the results obtained on the yield. The most reliable values to express the inhibition of the

2-[(2-nitrophenyl)amino]ethanol to the green algae Pseudokirchneriella subcapitata are considered to be 72h-ErC10 growth rate and the 72h-ErC50 growth rate 79.1 mg/L.

This study satisfies the guideline requirement for a growth inhibition test with Pseudokirchneriella subcapitata