alkyl substituted aryl diazo heterocyclic aryl ester

Short-term toxicity to aquatic invertebrates

Description of key information

No adverse effects observed at the limit of solubility

Additional information

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the test item Disperse Red DYGJ 0702 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 Red DYGJ 0702 and further dilution levels in a geometric series with a separation factor of 2 (nominal loading rates of 0.313 to 2.50 mg/L).

The test item Disperse Red DYGJ 0702 is a wine red powder and is sparingly soluble inwater (0.025 mg/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 as highest loading level in the test 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 and the following dilution level with a nominal loading of 2.50 mg/L were concentration related slightly red throughout the exposure period.

Twenty daphnids were exposed to each concentration leveland the control.

The concentrations of the test item Disperse Red DYGJ 0702 in the saturated solution and in the controlwereanalytically verified via HPLC-DAD at the start of the exposure (0 hours).

The measured concentration of the test item at the start of the exposure (0 hours) was below the SysQL of 0.1 mg/L of the test item in the

saturated solution and in the control. Concentrations of the test item in all tested loading levels were considered to be all below the SysQL throughout the exposure. Due to this fact, analytical monitoring of the other dilution levels at the start of the exposure and the analytical monitoring of all loading levels at the end of the exposure was not carried out in agreement with the sponsor.

According to OECD Guidance Document No 23 (2000) if an effect cannot be detected in a test with a saturated solution the result has to be

reported as no toxic effects at saturation. Therefore, exposures are expressed in terms of the original concentration of the test item in water at the start of the mixing period (loading rate) irrespective of the actual concentration of the test item in the saturated solution.

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 Red DYGJ 0702 and at any of the tested dilution levels, no significant effects were observed on Daphnia magna

 

EL-Values, NOEL and LOEL

(based on the nominal loading rate of the test item in the saturated solution)

Endpoints	Test duration [h]	Disperse Red DYGJ 0702 Nominal loading rate of the test item in the saturated solution [mg/L]
EL10/ EL50/ EL100	24	> 5.00
	48	> 5.00
NOEL	48	5.00
LOEL	48	> 5.00