Cetalkonium chloride

Endpoint summary

Description of key information

Hydrolysis

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.

Biodegradation in water

Biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical (from peer reviewed journal (J. Sanchez Leal et. al., 1994) and handbook (S. Gangolli, 1999)). The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Test chemical conc. used in the study were 2.5 and 10 mg/l, respectively. For the test chemical, the conventional disulphine- blue active substance test (DBAS test) and the dissolved organic carbon (DOC) disappearance method were used for monitoring their biodegradation. In these tests, the total biodegradation or conversion of the substrate toC02,water and biomass, would result in a decrease of both the DBAS and the organic carbon (DOC) values.The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

BCFBAF model of Estimation Programs Interface was used to predict the bioconcentration factor (BCF) of test chemical (2018). The bioconcentration factor (BCF) of test chemical was estimated to be 70.79 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

Adsorption / desorption

The adsorption coefficient Koc in soil and in sewage sludge of test chemical 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 weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 5.8. 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, p-toluamide, Aniline, 2,5 -Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4 -Nitrobenzamide, 1-naphthylamine, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT having Koc value ranging from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 3.010± 0.000 at 25°C. This log Koc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

Additional information

Hydrolysis

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.

Biodegradation in water

Various experimental key and supporting studies of the test chemical were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (J. Sanchez Leal et. al., 1994) and handbook (S. Gangolli, 1999),biodegradation experiment was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Test chemical conc. used in the study were 2.5 and 10 mg/l, respectively. For the test chemical, the conventional disulphine- blue active substance test (DBAS test) and the dissolved organic carbon (DOC) disappearance method were used for monitoring their biodegradation. In these tests, the total biodegradation or conversion of the substrate toC02,water and biomass, would result in a decrease of both the DBAS and the organic carbon (DOC) values.The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

In an supporting study from peer reviewed journal (J. Sanchez Leal et. al., 1994), biodegradation experiment was conducted for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 303 A (Simulation test–Aerobic sewage treatment: Coupled unit tests) under aerobic conditions. Test chemical conc. used for the study were 0.5, 1.0, 2.5, 10 and 20 mg/l, respectively. The percentage degradation of test chemical was determined to be 95-100 and > 75% degradation by test material analysis (%degradation) parameter in 7 days at conc. of 10 and 20 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test). Test chemical conc. used for the study were 5 and 40 mg/l, respectively. The percentage degradation of test chemical was determined to be ≥ 90 and ≥ 95% degradation by test material analysis (%degradation) parameter after a period of 24 and 48 hrs, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature

 

In an supporting study, biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test) under aerobic conditions. Test chemical conc. used in the study was 5 mg/l. Test chemical content was analyzed by the DBAS method and primary biodegradation was stated as the percentage of DBAS removal. DOC measurements were periodically performed and ultimate biodegradation was stated as the percentage of DOC removal. Ultimate biodegradation or mineralization was determined by DOC removal. DOC determination involves a sample membrane filtration to remove bacterial cells. To check whether the surfactant removal was really due to its biodegradation, TOC measurements were also carried out. TOC and DOC were determined by the combustion-infrared method using a TOC Analyzer (Shimadzu TOC-5050). For the DOC determinations, samples were subjected to membrane filtration (0.22mm pore size) and decarbonation by acidification with HCl prior to being analyzed by the TOC Analyzer. The percentage degradation of test chemical was determined to be 30 and 0% degradation by test material analysis (%degradation) & DOC parameter in 28 and 20 days, respectively. Thus, based on percentage degradation, test chemical is considered to be primary inherentlybiodegradable in nature.

 

For the target chemical from peer reviewed journal (Garcia et al, 1999), an experiment was performed to determine biodegradability of test chemical in anaerobic condition. The anaerobic sludge and the test chemical were incubated in 250 mL pressure-resistant glass bottles at 35 oC. The bottles were fitted with gas tight septa and aluminium crimp seals. After sealing the vessels and incubating them for about 1 hour at 35oC, excess gas was released to the atmosphere and the incubation proceeded in the dark. The evolved pressure was measured weekly with a digital manometer connected to a syringe needle which was inserted through the septum and excess of biogas was released. The increase in headspace pressure in the closed bottles was used to follow the biodegradation process. At the end of the test, after allowing the sludge to settle, vessels were opened and the dissolved part of carbon dioxide was determined as the concentration of inorganic carbon (IC) in the clear supernatant. For the measurements of inorganic carbon (IQ a carbon analyzer was used (Shimadzu TOC-5050). At the end of the test period, specific analyses of cationic surfactant both in the supematant Liquor and in the settled sludge were carried out to determine the primary biodegradation extent. The analytical procedure included diverse steps of extraction, clean-up and concentration of cationic surfactant [IO] and final quantification by the DBAS method. The biodegradability of test chemical is determined to be 28 % by using anaerobic sludge as inoculums in anaerobic condition and gas production as parameter in 200 days. This percent degradability value in 200 days indicates that test chemical is inherently biodegradable.

 

On the basis of overall results for test chemical(from peer reviewed journals and handbook), it can be concluded that the test chemicalcan be expected to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Predicted data and various experimental studies of the test chemical 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. The bioconcentration factor (BCF) of test chemical was estimated to be 70.79 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 chemical was estimated to be 236 dimensionless. The predicted BCF result based on the 5 OECD principles.

 

In a supporting weight of evidence study from authoritative databases (2017) for the test item,the bioaccumulation experiment was conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using a logKow of 3.23 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 71 dimensionless.

 

For the test chemical,the bioaccumulation study was conducted for estimating the BCF (bioaccumulation factor) value of test chemical (HSDB, 2017). The bioaccumulation factor (BCF) value was calculated using a logKow of 3.23 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of test chemical was determined to be 71 dimensionless.

 

On the basis of above results for test chemical, it can be concluded that the BCF value of test chemicalranges from 70.79 –236, respectively,which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

Adsorption / desorption

Experimental studies of the test chemical were reviewed for the adsorption end point which are summarized as below:

 

In an experimental key study from study report (2018),adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test item solution was prepared by accurately weighing 4 mg of test item and diluted with Acetonitrile up to 10 ml. Thus, the test solution concentration was 400 mg/l. The pH of test substance was 5.8. 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, p-toluamide, Aniline, 2,5 -Dichloroaniline, 4-nitrophenol, 2 - nitrophenol, 2-nitrobenzamide, 3-nitrobenzamide, Nitrobenzene, 4 -Nitrobenzamide, 1-naphthylamine, 1-naphtol, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, DDT having Koc value ranging from 1.25 to 5.63. The Log Koc value of test chemical was determined to be 3.010± 0.000 at 25°C. This log Koc value indicates that the test chemical has a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.

 

For the test chemical from peer reviewed journal (T. Mangialardi et. al., 1990),adsorption study was conducted for evaluating the adsorption capacity of test chemical onto Fuller’s earth at a temperature of 25°C and pH 7.0.The aqueous solutions of test chemical was prepared by using distilled water with a specific conductance less than 2 µmho/cm.Initial conc. of test chemical varies from 25 to 125 mg/dm3. Fuller’s earth was used as an adsorbent material.Prior to use, the earth was dried at 120 °C for 24 hr and sieved into two discrete particle size ranges: 45 to 63 µm and 150 to 180 µm. These two fractions were used as adsorbents and analyzed for mineralogical composition, density, porosity and specific surface area. The mineralogical composition was obtained from X-ray diffraction (XRD) analyses by using a Philips diffractometer with Cu Kα radiation. The solid density(Ps)and porosity (ϵ) were determined with a picnometer (for solids) and a Mercury porosimeter, respectively. Mineralogical compositions of Fuller’s earth (containing unsieved earth, particle size range of150-180 µm and 45-63 µm) contains Smectite, Quartz, Calcite and Feldspar in varying proportion. Batch reactors(4000-mL polypropylene vessels; internal diameter - 0.16 m) was used as a test vessel for the study. Thus, the adsorption rate experiments was performed by using these Batch reactors(4000-mL polypropylene vessels; internal diameter - 0.16 m) as a test vessel. Test vessel contained three liters of chemical (C0 = 25 mg/dm3) and a fixed amount (100 mg/dm3) of Fullers earth.The mixing in each vessel was realized with a four-blade, flat stainless steel impeller of 0.075 m diameter with a blade height of 0.015 m. The particles of Fuller's earth (particularly, 150 to 180 >m particle size range) were fully suspended and uniformly mixed throughout the solution when the impeller speed was above 170 rpm. Therefore, an impeller speed of 200 rpm was adopted in the adsorption rate experiments. Three 400-mL samples were withdrawn from each vessel at three different contact times(tc) between adsorbate and adsorbent. These samples were filtered on Whatman GF/C filter by discharging the first 200-mL portion of filtered liquid. The filtrate was then analyzed for residual test chemical concentration usingtwo-phase titration method and/or disulphine blue colorimetric method, respectively.Successively, adsorption rate tests were also performed at different values of the solution pH, over the range of 5.0 to 9.0. The pH was adjusted and maintained at a constant value throughout the experiment by using either 0.1 M HC1 or 0.1 M NaOH. The adsorption isotherm experiments were conducted at a pH of 7.0 and 25 °C by using the conventional bottle-point technique. Varying amounts of Fuller's earth were added to 1000 mLpolypropylene bottles containing 700 mL of surfactant solution (C o = 25; 75 and 125 mg dm-3). After pH adjustment, the bottles were sealed and placed on a rotary tumbler which was immersed in a water-bath. A contact time of six days was selected to ensure the system equilibrium. This value oft ewas 35 to 80% higher than the time actually necessary for each system to come to equilibrium when the samples were agitated with a rotary tumbler. After shaking, each sample was filtered and analyzed for the equilibrium surfactant concentration in the solution (Ceq).Experiments on blank samples, i.e., without Fuller's earth, revealed no appreciable adsorption of surfactant on bottle walls. Residual concentration of test chemical was determined using the two-phase titration method, when the concentration was higher than 10 mg/dm3as cationic species. According to this method, 50 mL of sample was titrated with 10-3M sodium laurylsulphate solution by using 10 mL of hydroalcoholic dimidium bromide-disulphine blue solution as an indicator and 15 mL of chloroform as an extracting solvent. Lower test chemical concentrations were determined by using the disulphine blue colorimetric method. A 20-fold excess of disulphine blue reagent (1.3 × 10 .3 M aqueous solution), a working pH of 5.0 (acetate buffer) and three extractions with 10-mL portions of reagent-grade chloroform were necessary to ensure the complete extraction of the test chemical-disulphine blue compound from the aqueous solution.The absorbance of the chloroform extract was measured with a spectrophotometer at the wavelength of 628 nm against a chloroform reference. The amount of test chemical in the sample was determined by reference to a previously prepared calibration graph.The critical micelle concentration (CMC) of test chemical (surfactant) was evaluated at 25 °C from conductivity measurements on solutions with different test chemical concentration. After a contact time of 60 min, the percentage adsorption of the test chemical was determined to be 40.5% of the equilibrium adsorption (Co - Ceq), respectively. A slight increase in the adsorption was, however, observed for test chemical, particularly when the solution pH was increased from 5.0 to 7.0.Thus based on percentage adsorption of test chemical, it indicates that the test chemical hasa moderate sorption tosoil and sediment and therefore have slow migration potential to ground water.

 

On the basis of above overall results for test chemical(from experimental study report and peer reviewed journal), it can be concluded that the log Koc value of test chemicalwas determined to be3.010,indicating that the test chemicalhas a moderate sorption to soil and sediment and therefore have slow migration potential to ground water.