5-amino-2-methoxybenzenesulphonic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Data is from Danish QSAR database.

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Determination of estimated 72 hrs EC50 value of test substance on Pseudokirchneriella subcapitata by three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database. It is a continuous (Q)SAR model based on structural features and numeric molecular descriptors.

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

Analytical monitoring:

not specified

Details on sampling:

No data available

Vehicle:

not specified

Details on test solutions:

No data available

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Selenastrum Capricornutum

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Remarks on exposure duration:

Estimated data

Hardness:

No data available

Test temperature:

No data available

pH:

No data available

Dissolved oxygen:

No data available

Salinity:

No data available

Conductivity:

No data available

Nominal and measured concentrations:

No data available

Details on test conditions:

No data available

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

552.65 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Domain applicability - Battery : IN

Details on results:

The EC50 was 552.6504 mg/l for 72 hrs of exposure period.

Table: Table showing the Pseudokirchneriella subcapitata 72 hr EC50 values estimated by two different models i.e, Leadscope and SciQSAR & the average EC50 value was given by the third model i.e, Battery model.

DK	Battery	Leadscope	SciQSAR
Pseudokirchneriella subcapitata 72 hr EC50 (mg/l)
Domain	IN

 

Where,

IN = inside applicability domain

Validity criteria fulfilled:

not specified

Conclusions:

Based on inhibition in growth rate of Pseudokirchneriella subcapitata, the estimated 72 hrs EC50 value by three different model i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database was evaluated to be 552.6504 mg/l.

Executive summary:

Based on the prediction done using the three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database, the short term toxicity on green algae was predicted for test substance 5-amino-2-methoxybenzene-1-sulfonic acid (CAS: 6470 -17 -3). The average EC50 value was given by the third model i.e, Battery model. On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance  5-amino-2-methoxybenzene-1-sulfonic acid is estimated to be 552.6504 mg/l for Pseudokirchneriella subcapitata during 72 hr exposure duration. Thus, on the basis of EC50 value, it can be concluded that the test chemical 5-amino-2-methoxybenzene-1-sulfonic acid can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

Description of key information

Based on the prediction done using the three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database, the short term toxicity on green algae was predicted for test substance 5-amino-2-methoxybenzene-1-sulfonic acid (CAS: 6470 -17 -3). The average EC50 value was given by the third model i.e, Battery model. On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance  5-amino-2-methoxybenzene-1-sulfonic acid is estimated to be 552.6504 mg/l for Pseudokirchneriella subcapitata during 72 hr exposure duration. Thus, on the basis of EC50 value, it can be concluded that the test chemical 5-amino-2-methoxybenzene-1-sulfonic acid can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

552.65 mg/L

Additional information

Based on the various prediction data for the target chemical and experimental data study have been reviewed to determine the toxic nature of 5-amino-2-methoxybenzene-1-sulfonic acid (CAS: 6470 -17 -3) on the growth of aquatic algae. The studies are as mentioned below:

 

First predicted study using based on the prediction done using the three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database, the short term toxicity on green algae was predicted for test substance 5-amino-2-methoxybenzene-1-sulfonic acid (CAS: 6470 -17 -3). The average EC50 value was given by the third model i.e, Battery model. On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance  5-amino-2-methoxybenzene-1-sulfonic acid is estimated to be 552.6504 mg/l for Pseudokirchneriella subcapitata during 72 hr exposure duration. Thus, on the basis of EC50 value, it can be concluded that the test chemical 5-amino-2-methoxybenzene-1-sulfonic acid can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

 

In second predicted study for the target chemical 5-amino-2-methoxybenzene-1-sulfonic acid, used from the OECD QSAR toolbox 2017. Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) predicted for 5-amino-2-methoxybenzene-1-sulfonic acid (6470-17-3). The EC50 value was estimated to be 223.435 mg/l when 5-amino-2-methoxybenzene-1-sulfonic acid (6470-17-3) exposed to Desmodesmus subspicatus for 72 hrs. Based on this value it can be concluded that the substance 5-amino-2- methoxybenzene-1-sulfonic acid (6470-17-3) is considered to not toxic to aquatic environment as per the criteria mentioned in CLP regulation.  

 

Experimental study for the read across chemical 4-amino-m-toluenesulfonic acid (98-33-9) from ABITEC report, 2017 was studied. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 4-amino-3- methylbenzenesulfonic acid according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 0, 30, 45, 67, 100, 150 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance 4-amino-3- methylbenzene- sulfonic acid, in Desmodesmus subspicatus was determined to be 110.6 mg/L. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP criteria.

 

Similarly in the fourth weight of evidence study for the structurally similar read across chemical 1,3-Phenylenediamine-4-sulfonic (88-63-1 ) from ABITEC lab report 2017. Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 1,3-Phenylenediamine-4-sulfonic Acid according to OECD Guideline 201. The stock solution 150 mg/l was prepared by dissolving light brown powder in OECD growth medium. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Sample tested at the concentrations 0, 0, 30, 45, 67, 100 and 150 mg/L. Test performed by the static system for 72hrs of exposure period. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance 1,3-Phenylenediamine-4-sulfonic Acid, in Desmodesmus subspicatus was determined to be 110 mg/L on the basis of effects on growth rate in a 72 hour study. This value indicates that the substance 1,3-Phenylenediamine-4-sulfonic Acid is likely to be non-hazardous to aquatic algae and cannot be classified as toxic as per the CLP classification criteria. 

 

Similarly in the fifth weight of evidence study for the structurally similar read across chemical (98-37-3) Water Research Pergamon Press, 1968. Short term toxicity to Chlorella pyrenoidosa (green algae) study was carried out for 72 hrs. Emerson strain of bacteria free, experimentally reproducible cultures of Chlorella pyrenoidosa was used as a test organism. The procedure involve the use of test tubes in both the screening and final tests. These test tubes contained 15 ml of inorganic culture medium, a predetermined amount of test chemical and 5 ml of algal culture. The tubes were incubated for 72 hrs and chlorophyll content of the algal suspensions was measured every 24 hrs. For chlorophyll measurement, the chlorophyll pigment was extracted with hot methanol in two separate extractions. An algal suspension, 2.5 ml, was removed from the test tube, centrifuged, washed with distilled water, and recentrifuged in preparation of chlorophyll analysis. After discarding the supernatant, the deposited cell material was coagulated by placing the cells in a boiling water bath for about 40 sec. About 2.5 ml of methanol were used in each extraction. Finally, the chlorophyll solution was diluted to a total volume of 10 ml with an acetone-water mixture (80 per cent by volume). A Beckman Spectrophotometer, Model DB, was used to measure the chlorophyll content according to MACKINv (1941) and ARNON (1949). For this a wavelength of 652 m/z was used because different proportions of chlorophyll a and b least affect the results at this wavelength. Control tubes containing no test chemical was also used in the experiment. Knop's solution, including the Hutner-EDTA microelement addition, was used as the culture medium. pH of culture medium was adjusted to 7.0 using KOH before use. The test organism was maintained under steady-state conditions, provided a chlorophyll content of 38 mg/l. Environmental control was rigidly maintained. The temp of water bath was 25 ± 1°C. The test apparatus consisted of a constant-temperature water bath, a light source containing four 200W fluorescent lamps with attached aluminum reflectors, a gas manifold to supply an air-CO2 mixture to each test tube, and a rack to hold the test tubes. A stream of 5 % CO2 in air gas mixture was supplied to culture medium in order to provide the inorganic carbon source and also to keep the algal ceils in suspension. Based on destruction of chlorophyll of test organism by test chemical Amino-1-phenol-4-sulfonic acid, the LOEC value was determine to be1500 mg/l and as no toxic effect at 1000 mg/l was observed, the NOEC value was determine to be 1000 mg/l. Thus, based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

 

Based on the predicted data for the target chemical (OECD QSAR, Danish QSAR, 2017) and experimental studies for the read across chemical obtain from various sources (ABITEC report, 2016) toxicity on algae was studied due to the exposure of 5-amino-2-methoxybenzene-1-sulfonic acid (CAS: 6470 -17 -3), and it was concluded that the substance 5-amino-2-methoxybenzene -1-sulfonic acid was consider as nontoxic and can be consider to be not classified as toxic to aquatic invertebrates as per CLP classification criteria.