Tributylmethylammonium chloride

Endpoint summary

Description of key information

Hydrolysis

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Tributylmethylammonium chloride can be expected to be ≥ 1 yr at pH 4, 7 and 9 & at a temperature of 20°C or 5 to 63 days, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Tributylmethylammonium chloride undergoes slow to negligible hydrolysis in water.

Biodegradation in water

The ready biodegradation of Tributylmethylammonium chloride (Methy tributyl ammonium chloride (MTBAC)) under the conditions of the carbon dioxide (CO2) evolution test (modified Sturm test) was investigated according to OECD guideline 301B and GLP principles. No significant biodegradation of Tributylmethylammonium chloride was observed. Therefore it is concluded that the substance was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test compound Tributylmethylammonium chloride (CAS No. 56375 -79 -2). If released in to the environment, 18.1% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Tributylmethylammonium chloride in water is estimated to be 8.666 days (208 hrs). The half-life (8.666 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of Tributylmethylammonium chloride in sediment is estimated to be 77.916 days (1870 hrs). Based on this half-life value, it indicates that Tributylmethylammonium chloride is not persistent in sediment.

Biodegradation in soil

The half-life period of Tributylmethylammonium chloride (CAS No. 56375 -79 -2) 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 Tributylmethylammonium chloride in soil is estimated to be 17.33 days (416 hrs). Based on this half-life value of Tributylmethylammonium chloride, 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.

Bioaccumulation: aquatic / sediment

BCFBAF model of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical Tributylmethylammonium chloride (CAS No. 56375 -79 -2). The bioconcentration factor (BCF) of Tributylmethylammonium chloride was estimated to be 3.162 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical Tributylmethylammonium chloride is not expected to bioaccumulate in the food chain.

Adsorption / desorption

The adsorption coefficient Koc in soil and in sewage sludge of test chemical Tributylmethylammonium chloride (CAS No. 56375-79-2) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately pipetting 4 microliter of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 389.2 mg/l. The pH of test substance was 4.2.Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, ptoluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4 -Nitrobenzamide, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, 3,5 -dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Tributylmethylammonium chloride was determined to be 1.104± 0.005 at 25°C. This log Koc value indicates that the substance Tributylmethylammonium chloride has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Additional information

Hydrolysis

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the half-life of the test chemical Tributylmethylammonium chloride (CAS no. 56375 -79 -2). The studies are as mentioned below:

 

The half-life of the test chemical was determined at different pH range. The study was performed at pH of 4, 7 and 9, & at a temperature of 20°C, respectively. The half-life period of test chemical was determined to be ≥ 1 yr at pH 4, 7 and 9, respectively & at a temperature of 20°C and thus test chemical was reported to be hydrolytically stable. On the basis of this, test chemical is considered to be not hydrolysable.

 

In an another study, the half-life of the test chemical was determined.The half-life value of test chemical was determined to be ranges from 5 to 63 days, respectively. Thus, based on the value, test chemical is considered to undergoe slow to negligible hydrolysis in water.

 

For the test chemical, the hydrolysis half-life value was determined.The hydrolysis of the quaternary nitrogen to a tertiary amine and an alcohol is thermodynamically very unfavorable with a delta G estimated from the delta H of reaction greater than +400 kJ mole. This is predicted to be a very endothermic reaction and should occur only under conditions of very high temperature.Thus, it can be concluded that the test chemical is stable in water and has a hydrolysis half-life of > 1 yr. On the basis of this, test chemical is considered to be not hydrolysable.

 

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the hydrolysis half-life value of the test chemical Tributylmethylammonium chloride can be expected to be ≥ 1 yr at pH 4, 7 and 9 & at a temperature of 20°C or 5 to 63 days, respectively. Thus, based on this half-life value, it can be concluded that the test chemical Tributylmethylammonium chloride undergoes slow to negligible hydrolysis in water.

Biodegradation in water

A single test concentration of 18mg/L (12 mg TOC/L) was tested during 28 days.

Max. 8% biodegradation of Tributylmethylammonium chloride (Methy tributyl ammonium chloride (MTBAC)) was observed after 28d.

In the toxicity control more than 25% biodegradation of the reference substance occurred within 14 days (40%, based on ThCO2) indicating that the test substance does not inhibit microbial activity at a nominal concentration of 18 mg/L.

The study is considered to be reliable without restrictions.

Biodegradation in water and sediment

Estimation Programs Interface (2018) prediction model was run to predict the half-life in water and sediment for the test compound Tributylmethylammonium chloride (CAS No. 56375 -79 -2). If released in to the environment, 18.1% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Tributylmethylammonium chloride in water is estimated to be 8.666 days (208 hrs). The half-life (8.666 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of Tributylmethylammonium chloride in sediment is estimated to be 77.916 days (1870 hrs). Based on this half-life value, it indicates that Tributylmethylammonium chloride is not persistent in sediment.

Biodegradation in soil

The half-life period of Tributylmethylammonium chloride (CAS No. 56375 -79 -2) 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 Tributylmethylammonium chloride in soil is estimated to be 17.33 days (416 hrs). Based on this half-life value of Tributylmethylammonium chloride, 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.

On the basis of available information, the test substance Tributylmethylammonium chloride can be considered to be not readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound Tributylmethylammonium chloride (CAS No. 56375-79-2) and supporting weight of evidence studies for its structurally similar read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In a prediction done using the BCFBAF Program of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical Tributylmethylammonium chloride (CAS No. 56375 -79 -2). The bioconcentration factor (BCF) of Tributylmethylammonium chloride was estimated to be 3.162 L/kg whole body w.w (at 25 deg C).

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the bioaccumulation i.e BCF for test substance Tributylmethylammonium chloride (CAS no. 56375 -79 -2) was estimated to be 5.62 dimensionless . The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative database (2018) for the test item,bioaccumulation experiment was conducted on test organism Cyprinus carpio for 28 days for evaluating the bioconcentration factor (BCF value) of test chemical. The study was performed according to OECD Guideline 305 (Bioconcentration: Flow-through Fish Test) or other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical was prepared in HCO-40.Test chemical nominal conc. used for the study was 0.1 mg/l and 0.01 mg/l, respectively. Analytical method involve the recovery ratio: Fish : 93.1 %, - Limit of quantitation : Test water : 1st concentration area : 3.1 microg/L, 2nd concentration area : 0.31 microg/L, Fish : 31 ng/g. Range finding study involve the LC50 (96h) 16.3 mg/L on Rice fish (Oryzias latipes). Lipid content of the test organisms at the start and end of exposure was determined to be 3.27% and 3.52%, respectively. The bioconcentration factor (BCF value) of test substance on Cyprinus carpio was determined to be in the range of 0.32-18 L/Kg and under steady state 7.3 L/Kg, respectively at a conc. of 0.1 mg/l and 3.2 - 47 L/Kg at a conc. of 0.01 mg/l, respectively.

 

For the test chemical,Bioaccumulation study was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of test chemical (authoritative database J-CHECK, 2018). The study was performed according to "OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)" and other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study was 2mg/land 0.2 mg/l, respectively. Analytical method involve the recovery ratio: Fish: 92.0 %, - Limit of quantitation: Test water: 1st concentration area; 0.049 mg/L, 2nd concentration area; 0.0049 mg/L, Fish: 0.54 microg/g. Range finding study involve the LC50(48h) ≥ 1000 mg/l on Rice fish (Oryzias latipes). Lipid content of the test organism Cyprinus carpio was determined to be 4.4%. The bioconcentration factor (BCF value) of test substance on Cyprinus carpio was determined to be in the range of ≤ 0.3 L/Kg at a conc. of 2 mg/l and ≤ 2.8 L/Kg at a conc. of 0.2 mg/l, respectively.

 

On the basis of above results for target chemical Tributylmethylammonium chloride (from modelling databases,2017), it can be concluded that the BCF value of test substance Tributylmethylammonium chloride ranges from 3.162 –5.62 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical Tributylmethylammonium chloride is not expected to bioaccumulate in the food chain.

Adsorption / desorption

The adsorption coefficient Koc in soil and in sewage sludge of test chemical Tributylmethylammonium chloride (CAS No. 56375-79-2) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals (Experimental study report, 2018). The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately pipetting 4 microliter of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 389.2 mg/l. The pH of test substance was 4.2.Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were Acetanilide, 4-chloroaniline, 4-methylaniline(p-Tolouidine), N-methylaniline, ptoluamide, Aniline, 2,5-Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4 -Nitrobenzamide, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, 3,5 -dinitrobenzamide, Benzamide, phenanthrene having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical Tributylmethylammonium chloride was determined to be 1.104± 0.005 at 25°C. This log Koc value indicates that the substance Tributylmethylammonium chloride has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.