7-acetamido-4-hydroxynaphthalene-2-sulphonic acid

Endpoint summary

Description of key information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model was used to predict the hydrolysis half-life of test compound 7 -acetamido-4 -hydroxy naphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). The estimated half-life of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 3950 years at pH 7 (at 25 deg C), indicating that it is not hydrolysable.

Biodegradation in water

Biodegradability of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS no. 6334 -97 -0) is predicted using QSAR toolbox version 3.3 (2017) with logKow as the primary descriptor. Test substance undergoes 0.57% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid

was estimated to be not readily biodegradable in water.

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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). If released in to the environment, 16.7% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid in sediment is estimated to be 337.5 days (8100  hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.122%), indicates that 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS No. 6334 -97 -0) 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, 83.2% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid in soil is estimated to be 75 days (900 hrs). Based on this half-life value of 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic 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 7 -acetamido-4 -hydroxynaphtha lene-2 -sulfonic acid (CAS No. 6334 -97 -0). The bioconcentration factor (BCF) of 7-acetamido-4-hydroxynaphthalene-2-sulfonic 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 7-acetamido-4-hydroxynaphthalene-2-sulfonic 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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). The soil adsorption coefficient i.e Koc value of 7 -acetamido-4 -hydroxynaphthalene-2-sulfonic acid was estimated to be 111.5 L/kg (log Koc=2.0472)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

Additional information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model was used to predict the hydrolysis half-life of test compound 7 -acetamido-4 -hydroxy naphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). The estimated half-life of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 3950 years at pH 7 (at 25 deg C), indicating that it is not hydrolysable.

Biodegradation in water

Various predicted data for the target compound 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS No. 6334-97-0) and supporting weight of evidence studies for its closest read across substance with logKow as the primary descriptor were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid(CAS No. 6334-97-0) was estimated.Test substance undergoes 0.57% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound7-acetamido-4-hydroxynaphthalene-2-sulfonic acid(CAS No. 6334-97-0) in the presence of mixed populations of environmental microorganisms was estimated. 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 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid is expected to be not readily biodegradable.

 

In a supporting weight of evidence study from authoritative database (J-CHECK, HSDB, 2017 and EnviChem, 2014) for the read across chemical 2, 4, 4’ – Trichloro – 2’-hydroxy diphenyl ether (CAS no. 3380-34-5), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across substance 2, 4, 4’ – Trichloro – 2’-hydroxy diphenyl ether. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) under aerobic conditions. 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 substance2, 4, 4’ – Trichloro – 2’-hydroxy diphenyl etherwas determined to be 0 and 1% by BOD and HPLC parameter in 28 days. Thus, based on percentage degradation, 2, 4, 4’ – Trichloro – 2’-hydroxy diphenyl ether is considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance 2, 4 – Dibromophenol (CAS no. 615-58-7) (J-CHECK and HSDB, 2017). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) under aerobic conditions. 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 read across substance 2, 4 – Dibromophenol was determined to be0 and 2% by BOD and HPLC parameter in 28 days. Thus, based on percentage degradation,2, 4 – Dibromophenol is considered to be not readily biodegradable in nature.

 

For the read across chemical (2-hydroxy-4-(octyloxy)phenyl)(phenyl)methanone (CAS no. 1843-05-6), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of read across chemical (2-hydroxy-4-(octyloxy)phenyl)(phenyl)methanone (HSDB, 2017). The study was performed according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) under aerobic conditions. Non-adapted activated sludge was used as a test inoculum during the study. Initial test substance conc. used in the study were 10.7 and 20.2 mg/l, respectively. The percentage degradation of substance (2 -hydroxy-4 -(octyloxy)phenyl)(phenyl) methanone was determined to be 5 -6% by using CO2 evolution parameter after 28 days. Thus, based on percentage degradation, (2 -hydroxy-4 -(octyloxy)phenyl)(phenyl)methanone is considered to be not readily biodegradable in nature.

 

In a supporting weight of evidence study from authoritative database (SRC PhysProp Database, 2017) and secondary source (HPVIS, 2017) for the read across chemical 2,4-bis(1,1-dimethylethyl)phenol (CAS no. 96-76-4),biodegradation experiment was conducted using method "BOD test for insoluble substances" for 28 days for evaluating the percentage biodegradability of read across substance 2,4 -bis(1,1 -dimethylethyl)phenol under aerobic conditions. Non-adapted activated sludge was used as a test inoculum for the study. Initial test chemical concentration used for the study was 34.5 mg/l. The percentage degradation of substance 2,4 -bis(1,1 -dimethylethyl)phenol was determined to be 2% by BOD parameter in 28 days.  Thus, based on percentage degradation, 2,4 -bis(1,1 -dimethylethyl)phenol is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (from authoritative database J-CHECK, HSDB, EnviChem, SRC PhysProp Database and secondary source HPVIS), it can be concluded that the test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid can be expected to be not 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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). If released in to the environment, 16.7% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid in sediment is estimated to be 337.5 days (8100  hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.122%), indicates that 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS No. 6334 -97 -0) 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, 83.2% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid in soil is estimated to be 75 days (900 hrs). Based on this half-life value of 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic 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 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid can be considered to be not readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS No. 6334-97-0) 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 7 -acetamido-4 -hydroxynaphtha lene-2 -sulfonic acid (CAS No. 6334 -97 -0). The bioconcentration factor (BCF) of 7-acetamido-4-hydroxynaphthalene-2-sulfonic 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 over the entire pH scale (pH 0 -14) of the test substance 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid (CAS no. 6334 -97 -0) was estimated to be 1.

 

Bioconcentration Factor (BCF) of test chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated using Chemspider database(ChemSpider, 2017). The bioconcentration factor of test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 1 at both pH 5.5 and 7.4, respectively.

 

Another predicted data was estimated usingSciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical 7-acetamido-4-hydroxynaphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). The bioconcentration factor (BCF) of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 1 (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 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 5.02 dimensionless . The predicted BCF result based on the 5 OECD principles. Thus based on the result it is concluded that the test substance 7 -acetamido-4 -hydroxynaph thalene-2 -sulfonic acid is non-bioaccumulative in nature.

 

In a supporting weight of evidence study from authoritative database J-CHECK, 2017 and EnviChem, 2014) for the read across chemical 3-hydroxy-2-naphthanilide (CAS no. 92-77-3),bioaccumulation experiment was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of read across substance 3 -hydroxy-2 -naphthanilide 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". Cyprinus carpio was used as a test organism for the study. Details on analytical methods involve the recovery ratio: Test water: 1st concentration area : 94.9 %, 2nd concentration area : 99.5 %, Fish : 81.7 %, Limit of detection : Fish : 0.29 ppm.HCO20, Crystal sugar was used as a vehicle. Test chemical nominal conc. used for the study were0.5 mg/l and 0.05 mg/l (w/v), respectively. Range finding study involve the TLm (48 hr) of ≥ 100 ppm (100 mg/l) (w/v) on Rice fish (Oryzias latipes). Lipid content of the test organism was determined to be 3.9%.The bioconcentration factor (BCF value) of substance 3-hydroxy-2-naphthanilide on Cyprinus carpio was determined to be ≤ 0.59 – 5.9 L/Kg at a conc. of 0.5 mg/l and ≤ 6.5 L/Kg at a conc. of 0.05 mg/l, respectively.

 

For the read across chemical (CAS no. 90-51-7), bioaccumulation test was conducted for 6 weeks for determination the bioconcentration factor (BCF) of read across chemical 6-Amino-4-hydroxy-2-naphthalenesulfonic acid on test organism Cyprinus carpio (J-CHECK, 2017). Nominal concentrations used was 1st Concentration area: 1.0 mg/L (w/v), 2nd Concentration area: 0.1 mg/L (w/v) and Range finding study was carried out on Rice fish (Oryzias latipes) TLm(48h) 335 ppm(w/v).Thus according to static Fish Test the BCF value 6-Amino-4-hydroxy-2-naphthalenesulfonic Acid was observed to be 0.1-0.5 L/kg at dose concentration 1.0 mg/L and 1-7.1 L/kg at dose concentration 0.1 mg/L on test organism Cyprinus carpio during 6 weeks period.

 

On the basis of above results for target chemical 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (from EPI suite, ACD labs,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,  2017) and for its read across substance (from authoritative database J-CHECK, 2017 and EnviChem, 2014), it can be concluded that the BCF value of test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid ranges from 1 – 5.02 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical7-acetamido-4-hydroxynaphthalene-2-sulfonic acidis not expected to bioaccumulate in the food chain.

Adsorption / desorption

Various predicted data for the target compound 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS No. 6334-97-0) were reviewed for the adsorption end point which are summarized as below:

 

In aprediction done using the KOCWIN 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 7 -acetamido-4 -hydroxynaphthalene-2 -sulfonic acid (CAS No. 6334 -97 -0). The soil adsorption coefficient i.e Koc value of 7 -acetamido-4 -hydroxynaphthalene-2-sulfonic acid was estimated to be 111.5 L/kg (log Koc=2.0472)  by means of MCI method (at 25 deg C). This Koc value indicates that the substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

The Soil Adsorption Coefficient i.e Koc value of test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS no. 6334 -97 -0) was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 1.84 (log Koc = 0.3 ± 1.0) and approx. 1.0 (log Koc = 0) at pH range 0 and 1-14 respectively(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017). This Koc value indicates that the test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid has a neligible sorption to soil and therefore have rapid migration potential to groundwater.

 

In an another prediction done by using ChemSpider Database (2017),the Soil Adsorption Coefficient i.e Koc value of test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid (CAS no. 6334 -97 -0) was estimated. The adsorption coefficient (Koc) value of substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 1 (Log Koc = 0) at pH 5.5 and 7.4, respectively. This Koc value indicates that the substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to groundwater.

 

Additional soil adsorption coefficient i.e Koc value of test chemical7 -acetamido-4 -hydroxynaphtha lene-2 -sulfonic acid (CAS No. 6334 -97 -0)was estimated using the SciFinder database (American Chemical Society (ACS), 2017).The soil adsorption coefficient i.e Koc value of 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 1 (log Koc = 0) (at 25 deg C). This Koc value indicates that the substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

 

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 adsorption coefficient i.e KOC for test substance 7-acetamido-4-hydroxynaphthalene-2-sulfonic acid was estimated to be 220 L/kg (log Koc = 2.342).The predicted KOC result based on the 5 OECD principles. This Koc value indicates that the substance 7 -acetamido-4 -hydroxynaph thalene-2 -sulfonic acid has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

On the basis of above overall results for target chemical7-acetamido-4-hydroxynaphthalene-2-sulfonic acid(from EPI suite, ACD labs,ChemSpider, SciFinder database and CompTox Chemistry Dashboard,2017), it can be concluded that the Koc value of test substance7-acetamido-4-hydroxynaphthalene-2-sulfonic acidranges from 1 –220indicating that the test chemical7-acetamido-4-hydroxynaphthalene-2-sulfonic acidhas a negligible to low sorption to soil and sediment and therefore have rapid to moderate migration potential to ground water.