Tetrabutylammonium bromide

Endpoint summary

Description of key information

Biodegradation in water

42-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item and toxicity control. the test was conducted using activated sludge, . The sampling site for collection of the activated sludge was selected ensuring that no known history of its contamination with the test item within the previous four years considering the history of possible agricultural, industrial or domestic inputs. The sampling depth was 1-2 feet from the aeration tank. The temperature of the activated sludge was measured (38º C) at the site of collection. Oxygen concentration of the activated sludge sample was 2.9 mg/L. The sample was transported to the test facility within 3 hours from collection and kept it aerobic during transport. This was pre-conditioned at the test temperature. 1 mL supernatant was diluted to 100 mL with mineral medium and from this solution 0.125 mL was added to 125 mL test bottles. This gave the bacterial count as 10e4 to 10e6 CFU/L. .The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The oxygen consumed by the test systems was corrected for oxygen consumption occurring in the blank test systems. The BOD Values (mgO2/mg) and percent biodegradation results for each test system are reported in tabes in additional information. The BOD42 value of test chemical was observed to be 1.03 mgO2/mg. ThOD was determined by calculation as 2.41 mgO2/mg. % degradation was calculated using the values of BOD and ThOD for test item and was determined to be  42.7 % at 20 ± 1°C. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 89.82 %. Degradation of Sodium Benzoate exceeds 64.67 % on 7 days & 88.62 % on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The toxicity control was > 25% after 14 days of exposure. Based on the results, the test chemical, under the test conditions, was considered to be inherently biodegradable in nature.

 

Biodegradation in water: simulation testing on ultimate degradation in surface water

Aerobic mineralisation of test chemical in water was studies as per the principles of the OECD Guideline 309 (Aerobic Mineralisation in Surface Water - Simulation Biodegradation Test) (Adopted 13th April 2004) under aerobic conditions. The surface water was collected from Kaveri River, Sangama, Ramnagar District, Karnataka State, India in a thoroughly cleansed container. The sampling site for collection of the surface water was selected ensuring that no known history of its contamination with the test item or its structural analogues within the previous four years considering the history of possible agricultural, industrial or domestic inputs. The pH and temperature of the water was measured at the site of collection and the depth of sampling and the appearance of the water sample. (e.g. color and turbidity) was also noted. Oxygen concentration of the surface layer was measured in order to demonstrate aerobic conditions. Depth of sampling was 1-2 feet and surface water was clear with no turbidity. The test water was stored at 4 to 6°C with continuous aeration prior use for a period not more than 4 weeks. Temperature (°C) at time of collection was 21.8°C, pH of temperature was 6.83, Oxygen concentration (mg/l) of 4.8 mg/l,  Dissolved organic carbon (%) of 3.9 mg/l, colony count consists of 4500 CFU/ml, Total organic carbon (TOC) of 3.8 mg/l, Nitrate (NO3- ) of 4.5 mg/l, Nitrite (NO2- ) of 0.62 mg/l, P of <0.1 mg/l, Orthophosphates (PO43-) of 0.19 mg/l, Total ammonia tot (NH4+ ) of <0.3 mg/l and BOD of <2.0 mg/l, respectively. Prior to use of surface water, the coarse particles were removed by filtration through a 100 μm mesh sieve. Test chemical conc. used in the study was 10 μg/L as low dose and 100 μg/L as high dose, respectively. Study was performed in duplicates in a 250 ml conical flasks which was covered with cotton plugs under continuous darkness. Test conditions involve a temperature of 12±2°C, pH of  6.83. Test vessel was kept in an incubator shaker at 12 ± 2°C in dark. Aerobic condition was maintained in the test system by continuous shaking. Agitation was provided to facilitate oxygen transfer from the headspace to the liquid so that aerobic conditions were adequately maintained. Additional to test vessels, 1 blank test vessel containing only the test water for all sampling intervals was included, 1 blank test vessel containing only the sterile test water was also treated at 10 µg/L (0.01 µg/mL) and 100 µg/L (0.1 µg/mL) conc. and duplicate test vessels with reference (aniline) (conc. 10 μg/l i.e. 0.01 mg/l) was also kept in the study. The concentration of test chemical residues in samples collected at different pre-determined interval zero-time (immediately after treatment day 0), day 1, day 3 day 7, day 14, day 28, day 45 and day 60 were diluted suitably with acetonitrile and at each sampling occasion, duplicate aliquots from each test concentration were subjected to analysis by a validated LC-MS/MS method. Simutaneously, samples were removed at regular intervals, measured pH and oxygen concentration. After that the samples were diluted at 1:1, v/v ratio with methanol to prevent further degradation prior to LC-MS/MS analysis. Shaking was continued at 12 ± 2°C in dark for using in other sampling intervals. The surface water samples were analyzed for the residues of test item by liquid chromatography with positive-ion electrospray ionization (ESI) tandem mass spectrometry using the mass ion transition m/z 244.1 -> 143.2 for primary quantification and the mass ion transition m/z 244.1 -> 101.1 for qualitative confirmation. High performance liquid chromatograph (Exion HPLC) equipped with a mass spectrometer (TQ 5500) was used with a column of  Phenomenex Luna, C18 (2), 4.6mm×150mm i.d., 3.0µm, column oven temperature of 40°C, mobile phase consists of Solvent A : 5 mM ammonium formate in Milli-Q® water and Solvent B : Acetonitrile in a ratio of 15 : 85, v/v, flow rate of 0.6 mL/min with splitter, respectively. Detection method involve the use of MS. Linearity range was evaluated to be in the range of 0.00026-0.02064 µg/ml, respectively. During method validation, acceptable recoveries were generated for the samples fortified at LOQ and 10 LOQ level. The % RSD (precision) was ≤20% at each fortification level. Recovery data from these samples demonstrated that test chemical was stable during analysis. The recoveries of all the samples analyzed were in the range of 70-110% with %RSD ≤ 20%. Analysis of the Day 0 samples at 10 μg/L and 100 μg/L test concentrations demonstrated quantitative recovery of test chemical. The average amount of test chemical present was 107.5% and 2.8% & 96.9% and 3.0% at Day 0 and Day 60, respectively following application of test chemical to test water at 10 μg/L (low dose) and 100μg/L (high dose). The average amount of test chemical present was 105.1% and 61.6% & 108.0% and 59.1% at Day 0 and Day 60, respectively following application of test chemical to sterile test water at 10 μg/L (low dose) and 100μg/L (high dose). The DT50 value was determined to be 10.2 d and 10.4 d at test chemical conc. of 10 μg/l and 100 μg/l at 12°C, respectively. 90% of test chemical in natural surface water was determined after 33.7 d and 34.5 d at test chemical conc. of 10 μg/l and 100 μg/l, respectively. Based on the these results, test chemical was degraded in surface water and sterile surface water. Hence, test chemical was considered to be not persistent in water.

Biodegradation in water: sediment simulation testing

In accordance with Annex IX column 2 of REACH regulation, test for this endpoint is scientifically not necessary and does not need to be conducted, since the substance is readily biodegradable i.e. not persistent based on the experimental result of surface water simulation biodegradation study.

 

Biodegradation in soil

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (2017). If released into the environment, 81% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 17.33 days (416 hrs). Based on half-life value, it is concluded that the test chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Additional information

Biodegradation in water

Experimental studies have been reviewed biodegradation in water endpoint and their results are summarized below.

42-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item and toxicity control. the test was conducted using activated sludge, . The sampling site for collection of the activated sludge was selected ensuring that no known history of its contamination with the test item within the previous four years considering the history of possible agricultural, industrial or domestic inputs. The sampling depth was 1-2 feet from the aeration tank. The temperature of the activated sludge was measured (38º C) at the site of collection. Oxygen concentration of the activated sludge sample was 2.9 mg/L. The sample was transported to the test facility within 3 hours from collection and kept it aerobic during transport. This was pre-conditioned at the test temperature. 1 mL supernatant was diluted to 100 mL with mineral medium and from this solution 0.125 mL was added to 125 mL test bottles. This gave the bacterial count as 10e4 to 10e6 CFU/L. .The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The oxygen consumed by the test systems was corrected for oxygen consumption occurring in the blank test systems. The BOD Values (mgO2/mg) and percent biodegradation results for each test system are reported in tabes in additional information. The BOD42 value of test chemical was observed to be 1.03 mgO2/mg. ThOD was determined by calculation as 2.41 mgO2/mg. % degradation was calculated using the values of BOD and ThOD for test item and was determined to be  42.7 % at 20 ± 1°C. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 89.82 %. Degradation of Sodium Benzoate exceeds 64.67 % on 7 days & 88.62 % on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The toxicity control was > 25% after 14 days of exposure. Based on the results, the test chemical, under the test conditions, was considered to be inherently biodegradable in nature.

Next study was reviewed from authoritative database (J check, 2018) in this Biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test chemical in this experiment activated sludge was used as a test inoculums. The initial test substance conc. used in the study was 7.2 mg/l. The percentage degradation of test substance was determined to be 0% by O2 consumption, DOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

By considering the result of first study which was performed according to OECD guideline and of Klimisch rating 1 the test chemical is considered to be ultimate inherently biodegradable in nature.

Biodegradation in water: simulation testing on ultimate degradation in surface water

Aerobic mineralisation of test chemical in water was studies as per the principles of the OECD Guideline 309 (Aerobic Mineralisation in Surface Water - Simulation Biodegradation Test) (Adopted 13th April 2004) under aerobic conditions. The surface water was collected from Kaveri River, Sangama, Ramnagar District, Karnataka State, India in a thoroughly cleansed container. The sampling site for collection of the surface water was selected ensuring that no known history of its contamination with the test item or its structural analogues within the previous four years considering the history of possible agricultural, industrial or domestic inputs. The pH and temperature of the water was measured at the site of collection and the depth of sampling and the appearance of the water sample. (e.g. color and turbidity) was also noted. Oxygen concentration of the surface layer was measured in order to demonstrate aerobic conditions. Depth of sampling was 1-2 feet and surface water was clear with no turbidity. The test water was stored at 4 to 6°C with continuous aeration prior use for a period not more than 4 weeks. Temperature (°C) at time of collection was 21.8°C, pH of temperature was 6.83, Oxygen concentration (mg/l) of 4.8 mg/l,  Dissolved organic carbon (%) of 3.9 mg/l, colony count consists of 4500 CFU/ml, Total organic carbon (TOC) of 3.8 mg/l, Nitrate (NO3- ) of 4.5 mg/l, Nitrite (NO2- ) of 0.62 mg/l, P of <0.1 mg/l, Orthophosphates (PO43-) of 0.19 mg/l, Total ammonia tot (NH4+ ) of <0.3 mg/l and BOD of <2.0 mg/l, respectively. Prior to use of surface water, the coarse particles were removed by filtration through a 100 μm mesh sieve. Test chemical conc. used in the study was 10 μg/L as low dose and 100 μg/L as high dose, respectively. Study was performed in duplicates in a 250 ml conical flasks which was covered with cotton plugs under continuous darkness. Test conditions involve a temperature of 12±2°C, pH of  6.83. Test vessel was kept in an incubator shaker at 12 ± 2°C in dark. Aerobic condition was maintained in the test system by continuous shaking. Agitation was provided to facilitate oxygen transfer from the headspace to the liquid so that aerobic conditions were adequately maintained. Additional to test vessels, 1 blank test vessel containing only the test water for all sampling intervals was included, 1 blank test vessel containing only the sterile test water was also treated at 10 µg/L (0.01 µg/mL) and 100 µg/L (0.1 µg/mL) conc. and duplicate test vessels with reference (aniline) (conc. 10 μg/l i.e. 0.01 mg/l) was also kept in the study. The concentration of test chemical residues in samples collected at different pre-determined interval zero-time (immediately after treatment day 0), day 1, day 3 day 7, day 14, day 28, day 45 and day 60 were diluted suitably with acetonitrile and at each sampling occasion, duplicate aliquots from each test concentration were subjected to analysis by a validated LC-MS/MS method. Simutaneously, samples were removed at regular intervals, measured pH and oxygen concentration. After that the samples were diluted at 1:1, v/v ratio with methanol to prevent further degradation prior to LC-MS/MS analysis. Shaking was continued at 12 ± 2°C in dark for using in other sampling intervals. The surface water samples were analyzed for the residues of test item by liquid chromatography with positive-ion electrospray ionization (ESI) tandem mass spectrometry using the mass ion transition m/z 244.1 -> 143.2 for primary quantification and the mass ion transition m/z 244.1 -> 101.1 for qualitative confirmation. High performance liquid chromatograph (Exion HPLC) equipped with a mass spectrometer (TQ 5500) was used with a column of  Phenomenex Luna, C18 (2), 4.6mm×150mm i.d., 3.0µm, column oven temperature of 40°C, mobile phase consists of Solvent A : 5 mM ammonium formate in Milli-Q® water and Solvent B : Acetonitrile in a ratio of 15 : 85, v/v, flow rate of 0.6 mL/min with splitter, respectively. Detection method involve the use of MS. Linearity range was evaluated to be in the range of 0.00026-0.02064 µg/ml, respectively. During method validation, acceptable recoveries were generated for the samples fortified at LOQ and 10 LOQ level. The % RSD (precision) was ≤20% at each fortification level. Recovery data from these samples demonstrated that test chemical was stable during analysis. The recoveries of all the samples analyzed were in the range of 70-110% with %RSD ≤ 20%. Analysis of the Day 0 samples at 10 μg/L and 100 μg/L test concentrations demonstrated quantitative recovery of test chemical. The average amount of test chemical present was 107.5% and 2.8% & 96.9% and 3.0% at Day 0 and Day 60, respectively following application of test chemical to test water at 10 μg/L (low dose) and 100μg/L (high dose). The average amount of test chemical present was 105.1% and 61.6% & 108.0% and 59.1% at Day 0 and Day 60, respectively following application of test chemical to sterile test water at 10 μg/L (low dose) and 100μg/L (high dose). The DT50 value was determined to be 10.2 d and 10.4 d at test chemical conc. of 10 μg/l and 100 μg/l at 12°C, respectively. 90% of test chemical in natural surface water was determined after 33.7 d and 34.5 d at test chemical conc. of 10 μg/l and 100 μg/l, respectively. Based on the these results, test chemical was degraded in surface water and sterile surface water. Hence, test chemical was considered to be not persistent in water.

Biodegradation in water: sediment simulation testing

In accordance with Annex IX column 2 of REACH regulation, test for this endpoint is scientifically not necessary and does not need to be conducted, since the substance is readily biodegradable i.e. not persistent based on the experimental result of surface water simulation biodegradation study.

 

Biodegradation in soil

The half-life period of test substance in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (2018). If released into the environment, 81% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test substance in soil is estimated to be 17.33 days (416 hrs). Based on this half-life value of test substance, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.