Sodium naphthalene-1-sulphonate

Endpoint summary

Description of key information

Stability:

Hydrolysis:

The hydrolysis half-life value of the test chemical sodium naphthalene-1-sulfonate (CAS no. 130-14-3) can be expected to be in range 5 -6 years at pH 7 and 200-211 days at pH 8 and Hydrolysis rate constant in range 0.038 L/mol-sec – 0.04 L/mol-sec. Based on these half-life values, it is concluded that the test chemical sodium naphthalene-1-sulfonate is not hydrolysable.

Biodegradation:

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound   sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3 ) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical  sodium naphthalene-1-sulfonate is expected to be not readily biodegradable.

Biodegradation in water and Sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of sodium naphthalene-1-sulfonate 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 sodium naphthalene-1-sulfonate 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 0.133%), indicates that sodium naphthalene-1-sulfonate is not persistent in sediment.

Biodegradation in Soil:

The half-life period of sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3) 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, 77.3% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of sodium naphthalene-1-sulfonate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of sodium naphthalene-1-sulfonate, 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:

Bioaccumulation: aquatic/ sediment:

Using BCFBAF Program (v3.00) model of EPI suite (2018) the estimated bio concentration factor (BCF) for test chemical sodium naphthalene-1-sulfonate (CAS no. 130-14-3)  is 3.162 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical sodium naphthalene-1-sulfonate is non-bioaccumulative in food chain.

Transport and distribution:

Adsorption/desorption:

The Adsorption Coefficient of test substance Sodium naphthalene-1-sulphonate (CAS No. 130-14-3) was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 1.255 ± 0.008 at 25°C.

This log Koc value indicates that the substance sodium naphthalene-1-sulfonate has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Additional information

Stability:

Hydrolysis:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the half-life of the test chemical sodium naphthalene-1-sulfonate (CAS no. 130-14-3).The studies are as mentioned below.

The first experimental study was reviewed from authoritative database (HSDB, 2018) in this study the half-life and base catalyzed second order hydrolysis rate constant was determined using a structure estimation method of the test chemical. The second order hydrolysis rate constant of test chemical was determined to be 0.038 L/mol-sec with a corresponding half-life of 6 yrs and 211 days at pH 7 and 8, respectively. Based on the half-life values, it is concluded that test chemical is not hydrolysable.

Next experimental study was also reviewed from authoritative database mentioned above in this study the base catalyzed second order hydrolysis rate constant was determined using a structure estimation method. The second order hydrolysis rate constant is determined to be 4.0 × 10-2L/mol-sec with a corresponding half lives of 5 years and 200 days at pH 7 and 8, respectively. Based on the half-life values, it is concluded that the test chemical is 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 sodium naphthalene-1-sulfonate (CAS no. 130-14-3) can be expected to be in range 5 -6 years at pH 7 and 200-211 days at pH 8 and Hydrolysis rate constant in range 0.038 L/mol-sec – 0.04 L/mol-sec. Based on these half-life values, it is concluded that the test chemical sodium naphthalene-1-sulfonate is not hydrolysable.

Biodegradation:

Biodegradation in water:

Predicted data study for target chemical sodium naphthalene-1-sulfonate(CAS no.  130- 14 -3) and experimental studies for its structurally similar read across chemical have been conducted and their results are summarized below for biodegradation in water endpoint.

 

In first study the Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound Sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical Sodium naphthalene-1-sulfonate is expected to be not readily biodegradable.

 

Next study was experimental study reviewed from journal Water research (1976) in this study a batch test in an open system was conducted for 5 days for evaluating the biodegradability of test chemical. Adapted activated sludge was used as a test inoculum obtained from a sewage plant is cultivated in a 1000ml volumetric cylinder. The mixture is aerated with pressure air. Every day 200 ml of the mixture is driven off so that the sludge age is 5 days. After driving off the 200ml of the mixture aeration is interrupted, and after sedimentationca.600 ml of the liquid phase is driven off. The residue (200 ml of the thickened activated sludge) is diluted with tap water to the volume ofca.800 ml and 600 mg/l of starch or glucose, 600 mg/l of peptone, 25 ml of a phosphate buffer pH 7.2, and the solution of the tested compound are added. Then the mixture in the cylinder is made up to 1000ml with tap water and aerated for 23 h (the recirculation ratio is 0-25). After this period the procedure is repeated. Test chemical conc. used for the study was 200 mg/l based on COD. To 1000-1500ml of the biological medium such amount of the solution of the substance tested is added that the initial COD is 200 mg/l. Then such an amount of the adapted activated sludge, washed and thickened by sedimentation, is dosed tothe medium that the concentration of the dry matter is 100 mg/l. Simultaneously, a blank test is prepared. The beaker was placed in a dark room with a roughly 3 constant temperature of 20±3°C on an electromagnetic stirrer and a pH of 7.2 for 120 hrs. The initial value of COD or organic carbon of the liquid phase was determined. Samples were filtered or centrifuged before analysis, are taken at suitable intervals. The decrease of the tested substance in the liquid phase is evaluated by determining COD or organic carbon. The results are compared with those of a blank test and standard compound decomposition. With the degree of degradation also the average specific rate of degradation is determined, expressed in terms of mg COD (or organic carbon) removed by a gramme of dry matter of the activated sludge per hour. The percentage degradation of test chemical was determined to be 0% degradation by COD parameter in 5 days. Thus, based on percentage degradation, test substance was considered to be not readily biodegradable in nature.

 

Another experimental study was reviewed from journal The Science of the Total Environment (1995) in this Biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance by bacteria as a test inoculum. Seeding bacteria was used as a test inoculum. The seeding bacteria had been cultured in a continuous anaerobic bioreactor at 37 + 1°C. Synthetic sewage, composed of glucose, peptone and corn steap liquor (carbon ratio = 1:1:2), is supplied into the reactor (3.0 g-C/l, 8.0 g-CS./.d). In this culture, > 95% acidic decomposition and > 90% methanogenic decomposition are achieved. A standard test and low conc. tests using 50 ml vials (total capacity: 68 ml) was employed. Ten test vials were prepared under the same conditions, and they were set in a water bath at 37°C ± 0.5”C. The original solution was added to the test inoculum and organic medium in oxygen-free water. At the starting time and after every week, two vials were opened simultaneously, and the concentration of organic compound was analyzed. The concentration of organic compound was determined by dissolved organic carbon (DOC) in the standard test and by chromatography in low conc. test. Biodegradation ratio is determined by analysing the decrease of DOC in the standard test. The percentage degradation of the test compound was determined to be < 30% degradation by DOC removal, chromatography in 28 days by using standard test and low conc. test. Thus, based on the percentage degradation, the test chemical was considered to be not readily biodegradable in nature.

 

Next both the studies are also experimental studies reviewed from authoritative database (J check, 2018)

 

In first study the biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of test substance. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 0 and < 0% by BOD, O2 consumption, TOC removal, test mat. analysis and UV-Vis parameter in 14 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

In another study the Biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of test substance. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of test substance was determined to be 3.8, 0.7, 0 and 5.8% by BOD, TOC removal, UV-VIs and HPLC parameter in 14 days. Thus, based on percentage degradation, test chemical is considered to be not readily biodegradable in nature.

 

By considering all the studies mentioned above it can be concluded that test chemical sodium naphthalene-1-sulfonate (CAS no.  130- 14 -3) is not readily biodegradable in nature.

Biodegradation in water and Sediments:

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of sodium naphthalene-1-sulfonate 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 sodium naphthalene-1-sulfonate 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 0.133%), indicates that sodium naphthalene-1-sulfonate is not persistent in sediment.

Biodegradation in Soil:

The half-life period of sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3) 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, 77.3% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of sodium naphthalene-1-sulfonate in soil is estimated to be 30 days (720 hrs). Based on this half-life value of sodium naphthalene-1-sulfonate, 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:

Bioaccumulation: aquatic/ sediment:

Various predicted data for the target compound sodium naphthalene-1 -sulfonate (CAS No. 130 -14 -3) and supporting weight of evidence study for its read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In first study BCF value of test chemical was estimated by using BCFBAF Program (v3.00) model of EPI suite (2018) the estimated bio concentration factor (BCF) for test chemical sodium naphthalene-1-sulfonate (CAS no. 130-14-3) is 3.162 L/kg wet-wt at 25 deg. c which does not exceed the bioconcentration threshold of 2000. Therefore it is concluded that test chemical sodium naphthalene-1-sulfonate is non-bioaccumulative in food chain.

 

Next study was reviewed 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 sodium naphthalene-1-sulfonate (CAS no. 130 -14 -3) was estimated to be 5.83 dimensionless. The predicted BCF result was based on the 5 OECD principles. Thus based on the result it is concluded that the test substance sodium naphthalene-1-sulfonate is non-bioaccumulative in nature.

 

Another study was reviewed from authoritative database (J check, 2018) in this study the Bioaccumulation experiment was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of test substance under static conditions. 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". Test chemical nominal conc. used for the study were 10 mg/l and 1 mg/l (w/v). Range finding study involve the TLm (48 hr) ≥ 4000 mg/l on Rice fish (Oryzias latipes).The bioconcentration factor (BCF value) of test substance on Cyprinus carpio was determined to be < 0.6 L/Kg at a conc. of 10 mg/l and < 6 L/Kg at a conc. of 1 mg/l, respectively, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

Further, to support above mentioned studies another study was reviewed from authoritative database (HSDB, 2017) in this study the bioaccumulation experiment was conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using an estimated log Kow of -0.14 and a regression derived equation. The BCF (bioaccumulation factor) value of test chemical was determined to be 0.5 dimensionless, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is considered to be non-accumulative in aquatic organisms.

 

Last study was reviewed from authoritative database (J check, 2018) in this study Bioaccumulation experiment was conducted on test organism Cyprinus carpio for 8 weeks for evaluating the bioconcentration factor (BCF value) of test substance under static conditions. Test chemical nominal conc. used for the study were 5 mg/l and 0.5 mg/l (w/v). Range finding study involve the TLm (48 hr) 610 mg/l on Rice fish (Oryzias latipes).The bioconcentration factor (BCF value) of test substance on Cyprinus carpio was determined to be< 0.6 L/Kg at a conc. of 5 mg/l and < 6 L/Kg at a conc. of 0.5 mg/l, respectively, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

On the basis of above results for target chemical sodium naphthalene-1-sulfonate (from, EPI suite, CompTox Chemistry Dashboard, 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 sodium naphthalene-1-sulfonate was in range from 3.162 to 5.83 dimensionless which does not exceed the bioconcentration threshold of 2000, indicating that the chemical sodium naphthalene-1 -sulfonate is not expected to bioaccumulate in the food chain.

Transport and distribution:

Adsorption/desorption:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical sodium naphthalene-1-sulfonate (CAS No. 130 -14 -3) 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 6.5. 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 functional similarity with the test substance and calibration graph prepared. The reference substances were 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, Direct Red 81, Benzoic acid methylester, Carbendazim, Benzoic acid phenylester, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzene, Pentachlorophenol, Phenol, N,Ndimethylbenzamide, 3,5-dinitrobenzamide, N-methylbenzamide, Benzamide, phenanthrene, Acetanilide having Koc value ranging from 1.25 to 4.09. The Log Koc value of test chemical sodium naphthalene-1-sulfonate was determined to be 1.255 ± 0.008 at 25°C. This log Koc value indicates that the substance sodium naphthalene-1-sulfonate has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.