3-methylsulphanilic acid

Endpoint summary

Description of key information

The skin sensitization potential of 4-amino-3-methylbenzenesulfonic acid (98-33-9) was estimated using OECD QSAR toolbox v3.3 with log kow as the primary descriptor and considering the six closest read across substances. 4-amino-3-methylbenzenesulfonic acid (98-33-9) was predicted to be sensitizing to the skin of male Dunkin-Hartley guinea pig.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation

Remarks:

in vivo

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:

Data is from QSAR toolbox version 3.3.

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.3

GLP compliance:

not specified

Type of study:

intracutaneous test

Specific details on test material used for the study:

- Name of test material (as cited in study report): 4-amino-3-methylbenzenesulfonic acid
- Molecular formula :C7H9NO3S
- Molecular weight :187.218 g/mole
- Substance type:Organic
- Physical state:Solid

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

No data available.

Route:

intradermal

Vehicle:

other: acetone:dimethy phthalate (1:9 ratio)

Concentration / amount:

30%

Day(s)/duration:

24 hour

Route:

epicutaneous, open

Vehicle:

other: acetone:dimethy phthalate (1:9 ratio)

Concentration / amount:

30%

Day(s)/duration:

24 hour

No. of animals per dose:

10 animals.

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures:No data available.
- Exposure period: 24 hour
- Test groups: 10
- Control group: No data available.
- Site: No data available.
- Frequency of applications: No data available.
- Duration: 24 hour
- Concentrations: 30%

B. CHALLENGE EXPOSURE
- No. of exposures: No data available.
- Day(s) of challenge: No data available.
- Exposure period: No data available.
- Test groups: 10
- Control group: No data available.
- Site: No data available.
- Concentrations: 30%
- Evaluation (hr after challenge): 24 hour

Challenge controls:

No data available.

Positive control substance(s):

not specified

Statistics:

No data available.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

30%

No. with + reactions:

10

Total no. in group:

10

Clinical observations:

Skin sensitization effect was observed.

Remarks on result:

positive indication of skin sensitisation

The prediction was based on dataset comprised from the following descriptors: "S M W N"
Estimation method: Takes highest mode value from the 5 nearest neighbours
Domain  logical expression:Result: In Domain

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

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 Alkyl arenes AND Aniline AND Aryl AND Sulfonic acid by Organic Functional groups

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Alkyl arenes AND Aniline AND Overlapping groups AND Sulfonic acid by Organic Functional groups (nested)

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Aliphatic Carbon [CH] AND Aliphatic Carbon [-CH2-] AND Aliphatic Carbon [-CH3] AND Aliphatic Nitrogen, one aromatic attach [-N] AND Aromatic Carbon [C] AND Hydroxy, sulfur attach [-OH] AND Miscellaneous sulfide (=S) or oxide (=O) AND Olefinic carbon [=CH- or =C<] AND Suflur {v+4} or {v+6} AND Sulfinic acid [-S(=O)OH] AND Sulfonate, aromatic attach [-SO2-O] by Organic functional groups (US EPA)

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Amine AND Aromatic compound AND Primary amine AND Primary aromatic amine AND Sulfonic acid AND Sulfonic acid derivative by Organic functional groups, Norbert Haider (checkmol)

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Non-Metals by Groups of elements

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Alkali Earth OR Halogens by Groups of elements

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Aliphatic Carbon [CH] AND Aliphatic Carbon [-CH2-] AND Aliphatic Carbon [-CH3] AND Aliphatic Nitrogen, one aromatic attach [-N] AND Aromatic Carbon [C] AND Hydroxy, sulfur attach [-OH] AND Miscellaneous sulfide (=S) or oxide (=O) AND Olefinic carbon [=CH- or =C<] AND Suflur {v+4} or {v+6} AND Sulfinic acid [-S(=O)OH] AND Sulfonate, aromatic attach [-SO2-O] by Organic functional groups (US EPA)

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Acid, aromatic attach [-COOH] OR Alcohol, olefinic attach [-OH] OR Amino, aliphatic attach [-N<] OR Azo [-N=N-] OR Carbonyl, olefinic attach [-C(=O)-] OR Carbonyl, one aromatic attach [-C(=O)-] OR Diarylketone OR Ester, aliphatic attach [-C(=O)O] OR Hydroxy, aliphatic attach [-OH] OR Hydroxy, aromatic attach [-OH] OR Ketone in a ring, olefinic aromatic attach OR Nitro, aromatic attach [-NO2] OR Oxygen, one aromatic attach [-O-] by Organic functional groups (US EPA)

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of log Kow which is >= -2.08

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.08

Interpretation of results:

other: Positive

Conclusions:

The skin sensitization potential of 4-amino-3-methylbenzenesulfonic acid (98-33-9) was estimated using OECD QSAR toolbox v3.3 with log kow as the primary descriptor and considering the six closest read across substances. 4-amino-3-methylbenzenesulfonic acid (98-33-9) was predicted to be sensitizing to the skin of male Dunkin-Hartley guinea pig.

Executive summary:

The skin sensitization potential of 4-amino-3-methylbenzenesulfonic acid (98-33-9) was estimated using OECD QSAR toolbox v3.3 with log kow as the primary descriptor and considering the six closest read across substances. 4-amino-3-methylbenzenesulfonic acid (98-33-9) was predicted to be sensitizing to the skin of male Dunkin-Hartley guinea pig.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin sensitization 

In different studies, 4-amino-3-methylbenzenesulfonic acid (98-33-9) has been investigated for potential for skin sensitization to a greater or lesser extent. The studies are based on in vivo experiments in guinea pig and human for target chemical 4-amino-3-methylbenzenesulfonic acid and its structurally similar read across substances Sulfanilic acid (CAS No: 121­57­3). The predicted data using the OECD QSAR toolbox has also been compared with the experimental data of read across substance.

The skin sensitization potential of 4-amino-3-methylbenzenesulfonic acid (98-33-9) was estimated using OECD QSAR toolbox v3.3 with log kow as the primary descriptor and considering the six closest read across substances. 4-amino-3-methylbenzenesulfonic acid (98-33-9) was predicted to be sensitizing to the skin of male Dunkin-Hartley guinea pig.

Based on the QSAR prediction done using the Danish (Q) SAR Database, the skin sensitization was estimated to be positive on guinea pig and human for4-amino-3-methylbenzenesulfonic acid. Thus it can be concluded that the substance 4-amino-3-methylbenzenesulfonic acid (98-33-9) has positive skin sensitization effects and based on the CLP criteria for classification it can be classified as “sensitizing” to skin sensitization effects.

It is further supported by the experimental data conducted byIFA (GESTIS) (GESTIS Substance Database, 2016 )on structurally similar read across substance Sulfanilic acid (CAS No: 121­57­3).The read across substances share high similarity in structure and log kow .Therefore, it is acceptable to derive information on skin sensitization from the analogue substance. The skin sensitization test was conducted on guinea pigs by guinea pig maximization test for Sulfanilic acid (CAS No: 121­57­3).Since skin sensitizing effects were observed for the test chemical in guinea pig. Therefore Sulfanilic acid (CAS No: 121­57­3) was considered to be sensitizing to guinea pigs.   

                                 

Thus based on the above predictions on 4-amino-3-methylbenzenesulfonic acid (98-33-9) as well as its read across substances and applying weight of evidence, it can be concluded that 4-amino-3-methylbenzenesulfonic acid (98-33-9) is not a skin sensitizer. Thus comparing the above annotations with the criteria of CLP regulation, 4-amino-3-methylbenzenesulfonic acid (98-33-9) can be classified as ‘skin sensitizer’.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Thus comparing the above annotations with the criteria of CLP regulation, 4-amino-3-methylbenzenesulfonic acid (98-33-9) can be classified as ‘skin sensitizer’.