5-amino-2-methoxybenzenesulphonic acid

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening tests

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

The supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Principles of method if other than guideline:

The data is predicted using the OECD QSAR toolbox version 3.3 with logKow as the primary descriptor.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 5-amino-2-methoxybenzene-1-sulfonic acid
- Common name : 5-Amino-2-methoxybenzenesulphonic acid
- Molecular formula : C7H9NO4S
- Molecular weight : 203.217 g/mol
- Smiles notation : O=S(=O)(O)c1c(OC)ccc(N)c1
- InChl : 1S/C7H9NO4S/c1-12-6-3-2-5(8)4-7(6)13(9,10)11/h2-4H,8H2,1H3,(H,9,10,11)
- Substance type : Organic
- Physical state : Solid

Oxygen conditions:

aerobic

Inoculum or test system:

other: Microorganisms

Duration of test (contact time):

28 d

Based on:

not specified

Parameter followed for biodegradation estimation:

other: BOD

Key result

Parameter:

other: BOD

Value:

0.091

Sampling time:

28 d

Remarks on result:

other: Other details not known

Details on results:

Test substance undergoes 0.09% degradation by BOD in 28 days.

The prediction was based on dataset comprised from the following descriptors: BOD
Estimation method: Takes average value from the 8 nearest neighbours
Domain  logical expression:Result: In Domain

((((((((("a" or "b" or "c" )  and "d" )  and "e" )  and "f" )  and ("g" and ( not "h") )  )  and "i" )  and ("j" and ( not "k") )  )  and "l" )  and ("m" and "n" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Anilines (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Strong binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Acid moiety AND Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as days - weeks by Biodeg primary (Biowin 4) ONLY

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 1) ONLY

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 2) ONLY

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Acid moiety AND Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Amides OR Anilines (amino-meta) OR Anilines (amino-ortho) OR Anilines (amino-para) OR Anilines (Hindered) OR Phenol Amines OR Phenols OR Phenols, Poly OR Polynitroanilines OR Salt by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Very fast by Bioaccumulation - metabolism half-lives ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Aniline AND Aryl AND Ether AND Sulfonic acid by Organic Functional groups

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Fused carbocyclic aromatic by Organic Functional groups

Domain logical expression index: "l"

Similarity boundary:Target: COc1ccc(N)cc1S(O)(=O)=O
Threshold=30%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "m"

Parametric boundary:The target chemical should have a value of Molecular weight which is >= 138 Da

Domain logical expression index: "n"

Parametric boundary:The target chemical should have a value of Molecular weight which is <= 248 Da

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

The test chemical 5-amino-2-methoxybenzene-1-sulfonic acid was estimated to be not readily biodegradable in water.

Executive summary:

Biodegradability of 5-amino-2-methoxybenzene-1-sulfonic acid (CAS no. 6470 -17 -3) is predicted using QSAR toolbox version 3.3 with logKow as the primary descriptor. Test substance undergoes 0.09% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 5-amino-2-methoxybenzene-1-sulfonic acid was estimated to be not readily biodegradable in water.

Description of key information

Biodegradability of 5-amino-2-methoxybenzene-1-sulfonic acid (CAS no. 6470 -17 -3) is predicted using QSAR toolbox version 3.3 (2017) with logKow as the primary descriptor. Test substance undergoes 0.09% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 5-amino-2-methoxybenzene-1-sulfonic acid was estimated to be not readily biodegradable in water.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Various predicted data for the target compound 5-amino-2-methoxybenzene-1-sulfonic acid (CAS No. 6470-17-3) and supporting weight of evidence studies for its read across substance 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 5-amino-2-methoxybenzene-1-sulfonic acid(CAS No. 6470-17-3) was estimated.Test substance undergoes 0.09% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical5-amino-2-methoxybenzene-1-sulfonic acidwas 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 compound 5-amino-2-methoxybenzene-1-sulfonic acid(CAS No. 6470-17-3) 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 chemical5-amino-2-methoxybenzene-1-sulfonic acidis expected to be not readily biodegradable.

 

In a supporting weight of evidence study from peer reviewed journal (P. Pitter, 1976) for the read across chemical 5-aminonaphthalene-2-sulfonic acid (CAS no. 119-79-9), a batch test in an open system was conducted for 5 days for evaluating the biodegradability of read across 5-aminonaphthalene-2-sulfonic acid. 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 sedimentation ca. 600mlof the liquid phase is driven off. The residue (200 ml of the thickened activated sludge) is diluted with tap water to the volume of ca.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 to the medium that the concentration of the dry matter is 100 mg/l. Simultaneously, a blank test is prepared. The beaker is 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 are determined. Samples. 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 5-aminonaphthalene-2-sulfonic acid was determined to be 0% degradation by COD parameter in 5 days. Thus, based on percentage degradation, test substance 5 -aminonaphthalene-2 -sulfonic acid was considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of read across substance 2-amino-5-methylbenzene sulfonic acid (CAS no. 88-44-8) (authoritative database J-CHECK, 2017 and secondary source OECD SIDS, 2003). The study was performed according to OECD Guide-line 301 C "Ready Biodegradability: Modified MITI Test (I)" under aerobic conditions. Aniline was used as a reference substance for the study. 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. Reference substance undergoes >40% and >60% degradation in 7 and 14 days, respectively. The percentage degradation of substance was determined to be 0 and <0% degradation by BOD, O2 consumption, TOC removal, Test mat. analysis and UV-Vis parameter in 14 days. Thus, based on percentage degradation, 2 -amino-5 -methylbenzene sulfonic acid is considered to be not readily biodegradable in nature.

 

For the read across chemical 2-aminonaphthalene-1-sulfonic acid (CAS no. 81-16-3) from authoritative database (J-CHECK, 2017 and EnviChem, 2014), biodegradation experiment was conducted for 14 days for evaluating the percentage biodegradability of read across substance 2 -aminonaphthalene-1 -sulfonic acid. 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 substance 2 -aminonaphthalene-1 -sulfonic acid 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, 2 -aminonaphthalene-1 -sulfonic acid is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical5-amino-2-methoxybenzene-1-sulfonic acid(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (from authoritative database J-CHECK & EnviChem and peer reviewed journal), it can be concluded that the test substance 5-amino-2-methoxybenzene-1-sulfonic acidcan be expected to be not readily biodegradable in nature.