Benzo[rst]phenanthro[10,1,2-cde]pentaphene-9,18-dione, reaction products with 1-chlorododecane

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is highly insoluble in water, hence indicating that aquatic toxicity is unlikely to occur

Justification for type of information:

According to QSAR estimation methods for various representative structures of C.I. Solvent Red (i.e. varying by 1-6 twelve carbon alkyl chain side groups) the water solubility ranged anywhere from 9.43E-13 to 6.52E-44 mg/L at 25 °C (WSKOW v1.42). Using the flask method, the water solubility of C.I. Solvent Red 175 was empirically determined to be less than 1.0E-4 g/L at 20°C. Using the HPLC method, the log (base 10) n-octanol/water partition coefficient (i.e. Log Kow) was determined to be > 6.5. The Log Kow estimates for the evaluated representative structures of C.I. Solvent Red 175 according to KOWWIN (v. 1.43) ranged from 15.17 to 44.92. The water solubility and Log Kow information clearly indicate that C.I. Solvent Red 175 is highly water insoluble.

The most water soluble structure of C.I. Solvent Red 175 (i.e. a single twelve carbon alkyl chain side group with smiles code = CCCCCCCCCCCCc1cc2c3c(ccc4c3c1c5ccc6c7c5c4ccc7c8ccccc8C6(=O))C(=O)c9c2)was evaluated for toxicity to green algae using the ECOSAR program (developed by the US Environmental Protection Agency’s Office of Chemical Safety and Pollution Prevention, v 1.11). The predicted EC50 for green algae was ~ 175,000x greater than the estimated water solubility limit. Furthermore, the predicted chronic value for green algae was ~688,000x greater than the estimated water solubility limit. Therefore, no toxic effects are predicted for the test material at water saturation, and a microorganism toxicity test is scientifically not necessary.

Description of key information

Neither acute nor chronic effects at water saturation were predicted for the test material, therefore acute and chronic testing with microorganisms is waived since the study is scientifically not necessary.