Quaternary ammonium compounds, trimethylsoya alkyl, chlorides

Hydrolysis

Administrative data

Endpoint:

hydrolysis

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 readily biodegradable

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Based on the results of the read across study, a similar complete removal of the test substance from the domestic wastewater treatment plants can be expected.  Further, based on the results of the soil biodegradation study with the read across substance, the DT50 value for degradation in the sediment compartment can be considered to be approximately 171 days at 12 °C.

Half-life in freshwater sediment:

171 d

at the temperature of:

12 °C

Surface water simulation testing: 

The study does not need to be conducted because the substance is readily biodegradable. 

Sewage treatment simulation testing 

A continuous activated sludge (CAS) study was conducted to determine the biodegradation of the read across substance, C12-16 ADBAC (49.2% active in water), in domestic wastewater according to OECD Guideline 303A, in compliance with GLP. In this study, the domestic waste microorganisms were exposed to the read across substance, by spiking at a nominal influent concentration of 49 mg/L (36 mg/L carbon) for a period of 58 days. An additional unit fed only with the domestic wastewater was maintained as the control group. All samples were analysed for NPOC. A strong increase in the concentration of NPOC was noted on Day 2 in the test units. This was probably caused by toxicity of the read across substance. The activated sludge acclimatised to the read across substance within a few days, resulting in a decrease of the NPOC concentrations. After 3 weeks, very high carbon removal percentages were achieved. The mean removal percentage in the test unit assessed using a HLPC-MS/MS was determined to be 99.998%, indicating ultimate biodegradation. Removal of the read across substance from the influent through adsorption onto sludge was only 0.023% on Day 58, showing that the main mechanism of elimination was biodegradation. Based on the results of the study, the read across substance was removed from wastewater at a very high percentage (approximately 99.998%) in the continuous activated sludge test. Removal of the read across substance from the influent through adsorption onto sludge was only 0.016 to 0.023% at two sampling times, demonstrating that the read across substance was removed almost completely and biodegraded. This suggests that the read across substance biodegrades almost completely in conventional biological wastewater treatment plants (Ginkel, 2007). Based on the results of the read across study, a similar complete removal of the test substance from the domestic wastewater treatment plants can be expected.  

Sediment simulation testing 

The study does not need to be conducted because the substance is readily biodegradable. Nevertheless, as per the ECHA E.16 guidance, the half-life in the sediment compartment will be a factor 10 higher than the half-life in soil. Therefore, the sediment half-life value of 171 days has been considered further for risk assessment.