Ethylbenzenesulphonic acid

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 substance Ethylbenzenesulphonic acid is readily biodegradable.

Biodegradation in water

Biodegradation study was conducted for 55 days for evaluating the percentage biodegradability of test substance Ethylbenzenesulphonic acid (CAS no. 57352-34-8) (E. A. Setzkorn and R. L. Huddleston, 1965). Ultraviolet spectroscopic analysis was carried out for studying the biodegradation. Sewage was used as a test inoculums for the study.The sample under study were added to half-gallon fruit jars and diluted to 1 liter to give a 5 ppm (5 mg/l) concentration with the aqueous synthetic medium.Synthetic medium was used as a test medium. The composition of the test medium includes NH4Cl, K3HPO4, MgSO4, KCl, Yeast extract and deionised water, respectively.In the synthetic system each jar was inoculated with 5 ml of raw sewage. After mixing the contents, the lids were loosened and the samples allowed to incubate on a bench top at room temperature.A control jar containing all ingredients except the sample, was prepared and inoculated in the same manner to serve as a reference medium for the UV analysis. Aliquots were removed at intervals for the UV analyses which were made in 1 cm cells using the solution from the control jar as the reference solution in the spectrophotometer. The wave length region from 300 to 200 mµ was scanned at each sampling period, since these compounds exhibited two usable absorption peaks, one near 220 mµ and another generally near 270 mµ.The percentage degradation of test substance Ethylbenzenesulphonic acid in the synthetic medium system was determined to be 100% by UV spectrophotomer parameter after 6 days. Thus, based on percentage degradation, Ethylbenzenesulphonic acid is considered to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). If released in to the environment, 24.4% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Ethylbenzenesulphonic acid in water is estimated to be 15 days (360 hrs). The half-life (15 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 Ethylbenzenesulphonic acid in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.0758%), indicates that Ethylbenzenesulphonic acid is not persistent in sediment.

 

Biodegradation in soil

The half-life period of Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 75.4% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of Ethylbenzenesulphonic acid in soil is estimated to be 30 days (720 hrs). Based on this half-life value of Ethylbenzenesulphonic acid, 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 (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). The bioconcentration factor (BCF) of Ethylbenzenesulphonic acid 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 Ethylbenzenesulphonic acid is not expected to bioaccumulate in the food chain.

Adsorption / desorption

KOCWIN model (v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). The soil adsorption coefficient i.e Koc value of Ethylbenzenesulphonic acid was estimated to be 30.64 L/kg (log Koc=1.4863)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance Ethylbenzenesulphonic acid has a negligible sorption to soil and sediment and therefore have rapid 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 substance Ethylbenzenesulphonic acid is readily biodegradable.

Biodegradation in water

Various experimental key and supporting studies for the target compound Ethylbenzenesulphonic acid (CAS No. 57352-34-8) were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (E. A. Setzkorn and R. L. Huddleston, 1965), biodegradation experiment was conducted for 55 days for evaluating the percentage biodegradability of test substance Ethylbenzenesulphonic acid (CAS no. 57352-34-8). Ultraviolet spectroscopic analysis was carried out for studying the biodegradation. Sewage was used as a test inoculums for the study.The sample under study were added to half-gallon fruit jars and diluted to 1 liter to give a 5 ppm (5 mg/l) concentration with the aqueous synthetic medium.Synthetic medium was used as a test medium. The composition of the test medium includes NH4Cl, K3HPO4, MgSO4, KCl, Yeast extract and deionised water, respectively.In the synthetic system each jar was inoculated with 5 ml of raw sewage. After mixing the contents, the lids were loosened and the samples allowed to incubate on a bench top at room temperature.A control jar containing all ingredients except the sample, was prepared and inoculated in the same manner to serve as a reference medium for the UV analysis. Aliquots were removed at intervals for the UV analyses which were made in 1 cm cells using the solution from the control jar as the reference solution in the spectrophotometer. The wave length region from 300 to 200 mµ was scanned at each sampling period, since these compounds exhibited two usable absorption peaks, one near 220 mµ and another generally near 270 mµ.The percentage degradation of test substance Ethylbenzenesulphonic acid in the synthetic medium system was determined to be 100% by UV spectrophotomer parameter after 6 days. Thus, based on percentage degradation, Ethylbenzenesulphonic acid is considered to be readily biodegradable in nature.

 

Another supporting biodegradation study was conducted for evaluating the percentage biodegradability of test substanceEthylbenzenesulphonic acidby using cell suspensions of Pseudomonas testosterone H-8 (CAS no. 57352-34-8) (Marilyn J. Ripin, et. al; 1975).Pseudomonas testosteroniH-8 was used as a test inoculums obtained from American Type Culture Collection, Rockville, Md., as ATCC 27911. For larger quantities of cells, 10-liter cultures in mineral salts medium with benzene sulphonic acid (BS) (1 g/liter) as carbon source were grown in a 14-liter Microferm fermenter. The temperature was 30⁰C, with an impeller speed of 250 rpm and aeration at 4 liters/min. Cell free extract was prepared by using the following method. Washed cells grown on BS were suspended at about 0.1 g (wet weight)/ml in distilled water containing 2-mercaptoethanol (10-4 M, final concentration) and disrupted by 5 min of sonic oscillation. Cell debris was removed by centrifugation at 10,000 x g for 10 min in a Sorvall RC-2B refrigerated centrifuge, and the supernatant fluid was used as the crude extract (protein content, 3 mg/ml).. Warburg vessels received substrate (10 Mmol), extract (1.5 mg of protein), and pH 7.0 phosphate buffer (50 Amol) in a total volume of 2.8 ml (plus 0.2 ml of 40% KOH in center well). For the isolation of meta cleavage intermediate from the test chemicalEthylbenzenesulphonic acid, washed cells (3.3 mg, dry weight) were incubated with substrate (10 µmol) in 10 ml of pH 8.0 tris(hydroxymethyl) aminomethane hydrochloride buffer (0.003 M) at 30⁰ C until maximum development of yellow color. Cells were removed by centrifugation at 10,000 x g for 10 min (Sorvall RC-2B), and the supernatant fluid was extracted three times with 25-ml portions of diethyl ether. The ether extract was discarded and the aqueous layer was adjusted to pH 2.0 with HCl before extracting again with three portions (25 ml each) of diethyl ether. This ether extract was recovered and immediately shaken with 10 ml of pH. Formation of the yellow color products could be monitored spectrophotometrically during incubation of EBS with cell suspensions 7.6 tris(hydroxymethyl)aminomethane. The meta cleavage products from EBS was recovered by ether extraction of acidified reaction mixtures and the absorption spectra were compared and it was observed that the product accumulated in test inoculums was same as that for 4-methylcatechol.The percentage degradation of test substance Ethylbenzenesulphonic acid was determined to be 72% degradation by Spectrophotomer parameter. Thus, based on percentage degradation, Ethylbenzenesulphonic acid is considered to be readily biodegradable in water.

 

In an supporting study from peer reviewed journal (Marilyn J. Ripin, et. al; 1971), biodegradation experiment was conducted for evaluating the percentage biodegradability of test substanceEthylbenzenesulphonic acidby using cell suspensions of Pseudomonas testosterone H-8 (CAS no. 57352-34-8). A bacterium capable of extensive growth on BS was isolated from pond water and identified tentatively as P. testosteroneH-8. This culture was maintained on slants of mineral salts medium containing 1 g of BS per liter. The mineral salt medium was used as a test medium for the study. It consisted of the composition(per liter of distilled water): (NH4)2SO4, 1.0 g; MgSO4.7H20, 0.2 g; KH2PO4, 3.0 g; K2HPO4, 7.0 g; CaCl2, 10 mg; FeSO4-7H20, 5 mg; MnSO4, 2 mg; CuSO4, 50 µg; H3BO4, 10 µg; ZnSO4, 70 µg; and MoO3, 10 µg, respectively. Conical flasks with metal closures received 50 ml of medium per 250-ml flask or 200 ml per 1,000-ml flask and were incubated with rotary shaking (250 rev/min) at 30 C in a water bath (Metabolyte shaker). Growth was assessed by turbidity measurements at 600 nm with a Spectronic 20 spectrophotometer and correlated with dry weight by means of a previously constructed calibration curve. Conventional manometric techniques were used to measure respiration of twice-washed cell suspensions. Vessels received 6 to 10 mg (dry weight) of washed cells, 50 µmoles of phosphate buffer (pH 7.0), and various amounts of substrate in a volume of 2.8 ml. The center well received 0.2 ml of 20% KOH; oxygen consumption was measured at 30⁰C. Compounds were applied to Whatman no. 1 filter paper and developed by ascending or descending chromatography by using one of the following solvent systems: 1) I -butanol-acetic acid-water (8:2:2); 2) methylethylketoneethanol-ammonia (30:6:2); 3) 1-butanol saturated with ammonia and 4) 1-butanol-ethanol-water (4:1:5), respectively. Pinacryptol yellow (0.05% in water) spray was employed to locate arylsulfonates by fluorescence in ultraviolet light. Paper chromatography of test substance by using four solvent systems revealed single spots which gave a pink fluorescence with pinacryptol yellow. No growth occurred in control flasks of the mineral salts base alone without an added carbon source. Washed cells prepared from cultures of P. testosteroni H-8 grown in mineral salts medium with Benzene sulphonic acid (BS) as the carbon source were capable of rapid oxidation of test substance Ethylbenzenesulphonic acid. Thus, based on this, chemical Ethylbenzenesulphonic acid can be considered to be biodegradable in water.

 

On the basis of above results for target chemical Ethylbenzenesulphonic acid (from peer reviewed journals), it can be concluded that the test substance Ethylbenzenesulphonic acid can be expected to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). If released in to the environment, 24.4% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of Ethylbenzenesulphonic acid in water is estimated to be 15 days (360 hrs). The half-life (15 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 Ethylbenzenesulphonic acid in sediment is estimated to be 135 days (3240 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.0758%), indicates that Ethylbenzenesulphonic acid is not persistent in sediment.

 

Biodegradation in soil

The half-life period of Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 75.4% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of Ethylbenzenesulphonic acid in soil is estimated to be 30 days (720 hrs). Based on this half-life value of Ethylbenzenesulphonic acid, 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 Ethylbenzenesulphonic acid can be considered to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound Ethylbenzenesulphonic acid (CAS No. 57352-34-8) and supporting weight of evidence study for its read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In aprediction done using theBCFBAF Program(v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). The bioconcentration factor (BCF) of Ethylbenzenesulphonic acid was estimated to be 3.162 L/kg whole body w.w (at 25 deg C).

 

In an another prediction done by using Bio-concentration Factor (v12.1.0.50374) moduleACD (Advanced Chemistry Development)/I-Lab predictive module, 2017), theBCF of the test substance Ethylbenzenesulphonic acid was estimated to be 1.99 and 1 at pH range 0 & 1-14, respectively.

 

Bioconcentration Factor (BCF) of test chemical Ethylbenzenesulphonic acid was estimated using Chemspider database(ChemSpider, 2017). The bioconcentration factor of test substance Ethylbenzenesulphonic acid was estimated to be 1 at both pH 5.5 and 7.4, respectively.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical Benzenesulphonic acid (CAS no. 98-11-3),bioaccumulation experiment was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical Benzenesulphonic acid. The bioaccumulation factor (BCF) value was calculated using a log Kow of -2.25 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of Benzenesulphonic acid was determined to be 1.15 dimensionless.

 

For the read across chemical 2-amino-5-methylbenzenesulfonic acid (CAS no. 88-44-8),bioaccumulation study was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of 2-amino-5-methylbenzenesulfonic acid (J-CHECK, 2017). The study was performed according to 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 were 2mg/l and 0.2mg/l, respectively. Range finding study involve the TLm (48 hr) 480 mg/l (w/v) on Rice fish (Oryzias latipes).The bioconcentration factor (BCF value) of substance 2-amino-5-methylbenzenesulfonic acid on Cyprinus carpio was determined to be ≤ 0.4 L/Kg at a conc. of 2mg/l and ≤ 4.0 L/Kg at a conc. of 0.2mg/l, respectively.

 

On the basis of above results for target chemical Ethylbenzenesulphonic acid (from EPI suite, ACD labsand ChemSpider,  2017) and for its read across substance from authoritative database (HSDB and J-CHECK, 2017), it can be concluded that the BCF value of test substance Ethylbenzenesulphonic acid ranges from 1– 3.162 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical Ethylbenzenesulphonic acid is not expected to bioaccumulate in the food chain.

Adsorption / desorption

Various predicted data for the target compound Ethylbenzenesulphonic acid (CAS No. 57352-34-8) and supporting weight of evidence study for its read across substance were reviewed for the adsorption end point which are summarized as below:

 

In aprediction done using theKOCWIN Program(v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical Ethylbenzenesulphonic acid (CAS No. 57352 -34 -8). The soil adsorption coefficient i.e Koc value of Ethylbenzenesulphonic acid was estimated to be 30.64 L/kg (log Koc=1.4863)  by means of MCI method (at 25 deg C).

 

The Soil Adsorption Coefficient i.e Koc value of test substance Ethylbenzenesulphonic acid was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 38.9, 5.14 and 1 at pH range 0, 1 and 2-14, respectively (log Koc value ranges from 0 to 1.6 ± 1.0)(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017).

 

AdditionalSoil Adsorption Coefficient i.e Koc value of test substance Ethylbenzenesulphonic acid (CAS no. 57352 -34 -8) was estimated using ChemSpider Database(ChemSpider, 2017). The adsorption coefficient (Koc) value of test substance Ethylbenzenesulphonic acid was estimated to be 1 (Log Koc = 0) at both pH 5.5 and 7.4, respectively.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical Benzenesulphonic acid (CAS no. 98-11-3),adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of read across chemical Benzenesulphonic acid. The adsorption coefficient (Koc) value was calculated using astructure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of substance Benzene sulphonic acid was estimated to be 12 (Log Koc = 1.079).

 

Another adsorption study was conducted for estimating the adsorption coefficient (Koc) value of the same read across chemical Benzenesulphonic acid (CAS no. 98-11-3) (HSDB, 2017). The adsorption coefficient (Koc) value was calculated using a logKow of -2.25 and a regression derived equation. The adsorption coefficient (Koc) value of substance Benzenesulphonic acid was estimated to be 1.4 (Log Koc = 0.1461).

 

For the read across chemical 4-hydroxybenzene-1-sulfonic acid (CAS no. 98-67-9),adsorption study was conducted for estimating the adsorption coefficient (Koc) value of read across chemical 4-hydroxybenzene-1-sulfonic acid (CAS no. 98-67-9) (HSDB, 2017). The adsorption coefficient (Koc) value was calculated using a logKow of -1.65 and a regression derived equation. The adsorption coefficient (Koc) value of test substance 4-hydroxybenzene-1-sulfonic acid was estimated to be 3.0 (Log Koc = 0.4771).

 

On the basis of above overall results for target chemicalEthylbenzenesulphonic acid(from EPI suite, ACD labsand ChemSpider,2017) and for its read across substance from authoritative database (HSDB, 2017), it can be concluded that the Koc value of test substanceEthylbenzenesulphonic acidranges from1–38.9,indicating that the test chemicalEthylbenzenesulphonic acidhas a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.