Disodium 4-hydroxynaphthalene-2,7-disulphonate

Endpoint summary

Description of key information

Biodegradation:

Biodegradation in water:

Biodegradability of target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349 -39 -7) was determined by using OECD QSAR tool box v3.4 with log Kow as primary descriptor. The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)  undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum. On the basis of percent biodegradability value it is concluded that target chemical

2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is 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 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349 -39 -7) .If released in to the environment, 16.3 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of the chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) 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 low whereas the half-life period of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) 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 0.553 %), indicates that test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not persistent in sediment.

Biodegradation in soil:

The half-life period of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349-39-7) 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 test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2), 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/sediments:

From BCFBAF Program (v3.00) model of EPI suite the estimated bio concentration factor (BCF) for 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349-39-7) is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that the test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not expected to bio accumulate in the aquatic environment.

Transport and Distribution:

Adsorption/desorption:

The Soil Adsorption Coefficient i.e Koc value of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No:20349-39-7) was estimated using EPI suite KOCWIN Program (v2.00) as 954.5 L/kg(log Koc= 2.9797)  by means of MCI method at 25 deg.C. This Koc value indicates that the substance 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) has a moderate sorption to soil and sediment and therefore have slow migration potential to groundwater.

Additional information

Biodegradation:

Biodegradation in water:

Predicted data for the target compound 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349-39-7) and supporting weight of evidence studies for its read acros substance were reviewed for the biodegradation end point which are summarized as below:

Biodegradability of target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS no. 20349-39-7) was determined by using OECD QSAR tool box v 3.4 with log Kow as primary descriptor. The target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)  undergoes 0.6285 % biodegradation in 28 days by considering BOD as parameter and microorganisms as inoculum. On the basis of percent biodegradability value it is concluded that target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

Another prediction done by using Estimation Programs Interface Suite (EPI suite, 2017) to estimate the biodegradation potential of the test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349 -39 -7) 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  2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not readily biodegradable.

In a supporting weight of evidence study done from authoritative database ( J check, 20170 the read across chemical dipotassium 7-hydroxynaphthalene-1, 3-disulfonate (CAS no. 842-18-2) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analysed by using BOD parameter. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 4 weeks of incubation the read across chemical showed 0% biodegradation by BOD parameter so it is concluded that it is not readily biodegradable.

Similarly, in another supporting weight of evidence study done from authoritative database ( J check, 2017) the read across chemical Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate (CAS no. 5460-09-3) was subjected to biodegradation test by taking sludge as inoculums at 30 mg/L concentration. Biodegradation was analyzed by using O2 consumption (BOD), TOC removal and test material analysis by UV vis parameter. The initial concentration of read across chemical was 100 mg/L and study design is of standard type. After 2 weeks (14 days) read across chemical Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate showed 0% biodegradation by O2 consumption (BOD) parameter, 5 % biodegradation by TOC removal parameter and less than 0 % biodegradation by test material analysis by UV Vis parameter in 14 days. So it is concluded that this read across chemical is not readily biodegradable.

On the basis of results of above mentioned studies for target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ( CAS no. 20349 -39 -7) (from OECD QSAR tool box v3.4 and EPI suite) and supporting weight of evidence study ( from J Check, 2017). It is concluded that the test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) can be 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 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349 -39 -7) .If released in to the environment, 16.3 % of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of the chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) 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 low whereas the half-life period of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) 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 0.553 %), indicates that test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) is not persistent in sediment.

Biodegradation in soil:

The half-life period of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349 -39 -7) 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 test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) in soil is estimated to be 30 days (720 hrs). Based on this half-life value of test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2), 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/sediments:

Various predicted data for the target compound 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349-39-7) and supporting weight of evidence study for its read across chemical were reviewed for the bioaccumulation end point which are summarized as below:

First predicted data study done from BCFBAF Program (v3.00) model of EPI suite the estimated bio concentration factor (BCF) for 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349-39-7) is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000.

Another predicted weight of evidence study done by using Bio-concentration Factor (v12.1.0.50374) module of(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017)the Bio-concentration Factor at range pH 1-14  of the chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)( CAS no.20349-39-7) estimated to be 1 dimensionless.

Further, predicted data study done 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 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS no.20349 -39 -7) was estimated to be 2.32 dimensionless it is based on the 5 OECD principles.

In supporting weight of evidence study done from authoritative database ( J check, 2017) the bioaccumulation test was conducted for 6 weeks for determination the bioconcentration factor (BCF) of read across chemical dipotassium 7-hydroxynaphthalene-1,3-disulfonate (CAS no 842-18-2) on test organism Cyprinus carpio. Nominal concentrations used in the study as 1st Concentration area: 1 ppm(w/v), 2nd Concentration area: 0.1 ppm(w/v) and Range finding study was carried out on Rice fish (Oryzias latipes) TLm(48h) = 1000 ppm(w/v). Thus according to static Fish test the BCF value for read across substance dipotassium 7-hydroxynaphthalene-1,3-disulfonate was observed to be ≤0.1 L/kg at dose concentration 1.0 mg/L and ≤ 1.0 L/kg at dose concentration 0.1 mg/L on test organism Cyprinus carpio during 6 weeks period. These BCF values indicate that the read across substance dipotassium 7-hydroxynaphthalene-1,3-disulfonate is not bioaccumulative in fish and food chain.

In another supporting weight of evidence study done from same source as mentioned above ( J check, 2017) the bioaccumulation test was conducted for 6 weeks for determination the bioconcentration factor (BCF) of read across substance Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate (CAS no 5460-09-3) on test organism Cyprinus carpio. Nominal concentrations used in the study as - 1st Concentration area: 2 mg/L, 2nd Concentration area : 0.2 mg/L and Range finding study was carried out on Rice fish (Oryzias latipes) TLm(48h) 880 ppm(w/v). Thus according to static Fish Test the BCF value for read across substance Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate was observed to be ≤ 0.3 L/kg at dose concentration 2 ppm(w/v) and ≤ 2.9 L/kg at dose concentration 0.2 ppm(w/v) on test organism Cyprinus carpio during 6 weeks period. These BCF values indicate that the read across chemical Sodium 5-amino-4-hydroxy-7-sulfonaphthalene-2-sulfonate is not bioaccumulative in fish and food chain.

On the basis of above results for target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No: 20349-39-7) (from EPI suite, ACD labs, and CompTox Chemistry Dashboard 2017) and for its read across chemicals (From J check) it can be concluded that the BCF value of test substance chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) ranges from 1 to 3.162 dimensionless which does not exceed the bioconcentration threshold of 2000, indicating that the target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2)is expected to be nonbioaccumulative in the food chain.

Transport and Distribution:

Adsorption/desorption:

Predicted data studies have been conducted for target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No:20349-39-7) for adsorption endpoint and their results are summarized below.

 

In first predicted data weight of evidence study the Soil Adsorption Coefficient i.e Koc value of 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No:20349-39-7) was estimated using EPI suite KOCWIN Program (v2.00) as 954.5 L/kg(log Koc= 2.9797)  by means of MCI method at 25 deg.C. This Koc value indicates that the substance 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) has a moderate sorption to soil and sediment and therefore have slow migration potential to groundwater.

 

Another predicted data study done 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 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS no. 20349 -39 -7) was estimated to be 131 L/kg (log Koc = 2.1172) .The predicted KOC result based on the 5 OECD principles. Thus based on the result it is concluded that the test substance 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

By compiling both above mentioned studies it is concluded that test chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) (CAS No:20349-39-7) can have log Koc value in range 2.1172 -2.9797, this value indicates that target chemical 2,7-Naphthalenedisulfonic acid, 4-hydroxy-, sodium salt (1:2) can have low to moderate sorption to and sediment and therefore have slow to moderate migration potential to ground water.