Sulisobenzone

Endpoint summary

Description of key information

Hydrolysis

The half-life of the test chemical was determined (Rensheng Zhuang et. al., 2013). The study was performed at a temperature of 25°C and pH 6.9, respectively. Initial test chemical conc. used was 10 mg/l. Experiment was performed with solutions of test chemical (10 mg L–1 in 0.01 M KH2PO4 + Na2HPO4 buffer (pH = 6.9). Firstly, 0.29 mL of 30% of NaOCl (sodium hypochlorite) or 0.4 mg of TCCA (trichloroisocyanuric acid) were added to 100 mL solution of test chemical and stirred in darkness at room temperature. Reaction mixtures were left to stand at room temperature for 24 h, after certain period of time reactions were stopped by addition of Na2SO3 and were afterwards analyzed by HPLC-DAD and UV-Vis spectrophotometer. The HPLC analyses were made on an Agilent 1100 Series chromatograph, coupled with DAD detector. The chromatographic separations were run on a Zorbax C8 column (4.6 mm ID × 250 mm, 5 μm) using a 60: 40 mixture of acetonitrile and acetic acid (pH 3) as the mobile phase. The column temperature was kept at 25 °C with the flow rate of 1.0 mL/min, injection volume 75 μL and the duration was 25 min with 5 min of post run. Test chemical and their chlorinated products were monitored at 240 nm. All the analyses were done in triplicates and are presented as mean values. Mass spectra were recorded on a 6224 Agilent Accurate-Mass TOF mass spectrometer. As the starting material was completely consumed in less than 15 min and there is almost no difference in the composition of reaction mixture in 15 min, 1 h or 24 h after the setup of the reaction. Thus, the half-life value of test chemical can be considered to be< 15 min. Based on this, it can be concluded that the test chemical was rapidly hydrolysable in water.

Additional information

Hydrolysis

The half-life of the test chemical was determined (Rensheng Zhuang et. al., 2013). The study was performed at a temperature of 25°C and pH 6.9, respectively. Initial test chemical conc. used was 10 mg/l. Experiment was performed with solutions of test chemical (10 mg L–1 in 0.01 M KH2PO4 + Na2HPO4 buffer (pH = 6.9). Firstly, 0.29 mL of 30% of NaOCl (sodium hypochlorite) or 0.4 mg of TCCA (trichloroisocyanuric acid) were added to 100 mL solution of test chemical and stirred in darkness at room temperature. Reaction mixtures were left to stand at room temperature for 24 h, after certain period of time reactions were stopped by addition of Na2SO3 and were afterwards analyzed by HPLC-DAD and UV-Vis spectrophotometer. The HPLC analyses were made on an Agilent 1100 Series chromatograph, coupled with DAD detector. The chromatographic separations were run on a Zorbax C8 column (4.6 mm ID × 250 mm, 5 μm) using a 60: 40 mixture of acetonitrile and acetic acid (pH 3) as the mobile phase. The column temperature was kept at 25 °C with the flow rate of 1.0 mL/min, injection volume 75 μL and the duration was 25 min with 5 min of post run. Test chemical and their chlorinated products were monitored at 240 nm. All the analyses were done in triplicates and are presented as mean values. Mass spectra were recorded on a 6224 Agilent Accurate-Mass TOF mass spectrometer. As the starting material was completely consumed in less than 15 min and there is almost no difference in the composition of reaction mixture in 15 min, 1 h or 24 h after the setup of the reaction. Thus, the half-life value of test chemical can be considered to be< 15 min. Based on this, it can be concluded that the test chemical was rapidly hydrolysable in water.

Hydrolysis endpoint can also be considered for waiver as per in accordance with column 2 of Annex VIII of the REACH regulation, testing for this endpoint is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable.