2,9-dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

Endpoint summary

Description of key information

Short-term toxicity to fish

One test with a read across substance is available. An acute toxicity test on Zebra fish (Brachydanio rerio) had been performed (reliability category 1, compliant to GLP) as a limit test with daily renewal of the test medium (semistatic). The test item is poorly soluble in water. Therfore no analytical determination of the actual test concentration at a nominal concentration of 100 mg/L could be performed.
At these test conditions, the test item proved to be non-toxic to Zebra fish (no deaths or any abnormalities in treatment as well as control group):
NOEC (96h) = 100 mg/L nominal concentration,
LC50 (96h) > 100 mg/L nominal concentration.

 

Long-term toxicity to fish

One Key Study with a Read across substance is available. In this study the test item did not cause any effects to Zebrafish (growth rates, lethal and non lethal effects), at the saturated solution level (prepared from 10 mg/L). Therefore the NOEC after 28 days of exposure was the saturated solution level (prepared from 10 mg/L).

 

Short-term toxicity to aquatic invertebrates

Three Key study with read across substances are available. In one key study, at the saturated solution of the test item no biologically significant effect was determined.

Both results with the read across substances show the same result.

In a 48 hour toxicity test (reliability category 1, compliant to GLP) on Daphnia manga Straus performed as a static limit test due to the low solubility of the submission substance, the NOEC (48 h) had been determined to be the nominal concentration of 100 mg/L. The EC50 is higher than the nominal limit concentration (100 mg/L).

In a 48 hour toxicity test (reliability category 1, compliant to GLP) on Daphnia manga Straus performed as a static limit test due to the low solubility of the submission substance, the NOEC (48 h) had been determined to be the nominal concentration of 100 mg/L. The EC50 is higher than the nominal limit concentration (100 mg/L). The actual concentration could not be determined due to the low solubility of the submission substance in water and the salt concentration present in the ISO-test medium.

 

Long-term toxicity to aquatic invertebrates

One Key Study with Read across substance is available. In this prolonged toxicity study in Daphnia magna over 21 days the following effect concentrations were obtained:

NOEC (immobility):
> 1 mg/L (nominal concentration), > solubility limit ¿ 20 µg/L)
NOEC (reproduction rate):
> 1 mg/L (nominal concentration), > solubility limit ¿ 20 µg/L)
No adverse effects of C.I. Pigment Red 122 on Daphnia magna were observed at the maximum tested concentration of 1 mg/L (nominal concentration) which was above the solubility limit (¿ 20 µg/L) of the test substance in the test water.

 

Toxicity to algae

Two key studies with read across substances are available. In test with the substance itself no inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > saturated solution.

In the study with the read across substance also no toxic effects were found.

In a fresh water algal growth inhibition test with Desmodesmus subspicatus the toxicity of the submission substance to aquatic plants had been tested (reliability category 2, compliant to GLP). A static limit test had been performed at a nominal concentration of 100 mg/L due to the poor solubility of the test item. The submission substance proved to be non-toxic to Desmodesmus subspicatus under the applied test conditions:

NOEC (growth rate / yield, 72h) equal to or larger as 100 mg/L;

EC50 (growth rate / yield, 72h) > 100 mg/L;

 

Toxicity to microorganisms

Two key studies with read across substances are available.

The substance itself is not toxic at concentrations of 1000 mg/L to activated sludge of a municipal sewage treatment plant.

A respiration inhibition test with a read across substance had been performed according to relevant guidelines and compliant to GLP (reliability category 1). The test was conducted as a limit test at 100 mg/L nominal concentration added directly to the test vessels as the test item is of very poor water solubility. At the limit concentration, the test item had no significant inhibitory effect on respiration rate of activated sludge as compared to the controls (1.8% after 3 hours).

Results with the reference substance 3,5-dichlorophenol with an EC50 (3 hours) of 12 mg/L confirmed the suitability of the test.