N-alkylester N-substituted heterocyclic diazo aryl amine

Short-term toxicity to aquatic invertebrates

Description of key information

The test item showed no effects up to the limit of water solubility and beyond.

Additional information

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item were determined according to EPA OPPTS Draft Guideline 850.1010 (1996) and OECD 202 (2004) which is equivalent to the Council Regulation (EC) No.440/2008 Method C.2 (2008).

 

The study was conducted under static conditions over a period of 48 hours with a saturated solution with a nominal loading of 5.00 mg/L of the test item Disperse Green GNA and further dilution levels in a geometric series with a separation factor of 2: 0.313 - 0.625 - 1.25 - 2.50 - 5.00 mg/L (corresponding to nominal loading rates of 6.25 - 12.5 - 25.0 - 50.0 - 100 %).

 

The test item is a black powder and has a water solubility of < 29.3 µg/L. The saturated solution with a nominal loading of 5.00 mg/L of the test item was prepared with dilution water one day before the start of the exposure (at -24 hours) and was used for testing and as stock solution for the preparation of all further tested dilution levels. A test item dispersion of 5 mg/L was stirred with approximately 1100 rpm for 24 hours at room temperature. After completion of stirring, the test item dispersion was filtered with a membrane filter (0.2 µm, RC, Macherey-Nagel) to achieve the saturated solution. Further dilution levels were prepared by diluting the saturated solution with dilution water. The tested solutions were visually clear throughout the exposure period. The saturated solution was slightly blue.

 

Twenty daphnids were exposed to each concentration level and the control.

 

The concentrations of the test item Disperse Green GNA in the saturated solution, all tested dilution levels and in the control were analytically verified via HPLC-UV at the start (0 hours) and at the end of the exposure (48 hours).

 

The measured concentrations of the test item at the start of the exposure (0 hours) were in the range of < LOQ (0.158 mg/L of the test item) at the lowest loading level to 0.546 mg/L in the saturated solution. At the end of the exposure (48 hours), the measured test item concentrations were in the range of < LOQ at the lowest loading level to 0.604 mg/L (111 % of the initially measured value) in the saturated solution.

 

Since the measured test item concentrations did not remain within ±20 % of nominal concentrations, the effect values are based on the geometric mean measured concentrations of the test item calculated to be: 0.0790 – 0.0994 – 0.144 – 0.228 – 0.574 mg/L. Measured concentrations below 70 % of the LOQ were taken into account with half of the LOQ (0.0790 mg/L) for the calculation of the geometric mean measured concentrations.

 

The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 hours) and at the end of the exposure

(48 hours), were within the acceptable limits. The validity criteria of the test guidelines were fulfilled.

At the saturated solution with a nominal loading of 5.00 mg/L of the test item Disperse Green GNA, which corresponds to a geometric mean measured concentration of 0.574 mg/L, and at any of the tested dilution levels, no significant effects were observed on Daphnia magna.

  

EC-Values, NOEC and LOEC

(based on the geometric mean measured concentration of the test item in the saturated solution)

Endpoints	Test duration [h]	Geometric mean measured test item concentration   [mg/L]
EC10/ EC50/ EC100	24	> 0.574
	48	> 0.574
NOEC	48	0.574
LOEC	48	> 0.574