4-hydroxybenzenesulphonic acid

Endpoint summary

Description of key information

Corrositex: penetration time >3 minutes <30 minutes

in vivo rabbit study: corrosive (read-across to 4 -methylbenezensulfonic acid)

in vivo rabbit study: not irritating (read-across to sodium salt of 4 -hydroxybenzenesulfonic acid)

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

raw data are not available for analysis

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

No information on the conduct of the test is given in the publication, however it is assumed that the test was conducted at least similar to guideline.

GLP compliance:

not specified

Test system:

artificial membrane barrier model

Irritation / corrosion parameter:

penetration time (in minutes)

Value:

> 3 - < 30

Vehicle controls validity:

not specified

Negative controls validity:

not specified

Positive controls validity:

not specified

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Study period:

1988

Justification for type of information:

4-Hydroxybenzenesulfonic acid and 4-methylbenzenesulfonic acid are structurally closely related. Using the OECD Toolbox to predict possible read-across candidates for 4-hydroxybenzenesulfonic acid, 4-methylbenzenesulfonic acid was the closest match in terms of structure. Additionally, similar physical-chemical properties support the similarity of the structures. Both substances are corrosive (see relevant endpoint) and not mutagenic. Overall, read-across from 4-methylbenzenesulfonic acid to 4-hydroxybenzenesulfonic acid is considered adequate. Further, data from sodium 4-hydroxybenzenesulfonate are available. Given that the sodium component is considered not relevant for toxicity, it is feasible to assume that any toxicity observed would originate from the 4-hydroxybenzenesulfonate compound. Nevertheless, the pH differences between the acid and the salt have to be kept in mind with regard to corrosive properties.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

erythema score

Basis:

animal #1

Remarks:

4-methylbenzenesulfonic acid

Time point:

other: 30-60 min, 24 h, 48 h, 72 h, 7 d

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: individual scores: 2 - 3 - 4 - 4 - 2; 4 h contact time

Irritation parameter:

erythema score

Basis:

animal #1

Remarks:

4-methylbenzenesulfonic acid

Time point:

other: 24 - 48 - 72 h

Score:

0.7

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: individual scores: 1 - 1 - 0; 3 min contact time

Irritation parameter:

erythema score

Basis:

animal #2

Remarks:

4-methylbenzenesulfonic acid

Time point:

other: 24 - 48 - 72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: individual scores: 2 - 1 - 0

Irritation parameter:

erythema score

Basis:

animal #3

Remarks:

4-methylbenzenesulfonic acid

Time point:

other: 24 - 48 - 72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible

Remarks on result:

other: individual scores: 0 - 0 - 0; 3 min contact time.

Irritation parameter:

edema score

Basis:

animal: #1, #2, #3

Remarks:

4-methylbenzenesulfonic acid

Time point:

other: 24 - 48 - 72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: individual scores: 0 - 0 - 0; 3 min contact time.

Irritation parameter:

other: Draize score

Basis:

mean

Remarks:

5000 mg/L sodium 4-hydroxybenzenesulfonate

Time point:

24/48 h

Score:

0.3

Max. score:

4

Reversibility:

fully reversible within: 72h

Irritation parameter:

other: Draize score

Basis:

mean

Remarks:

5000 mg/L sodium 4-hydroxybenzenesulfonate

Time point:

72 h

Score:

0

Max. score:

4

Irritation parameter:

other: Draize score

Basis:

mean

Remarks:

2000 mg/L sodium 4-hydroxybenzenesulfonate

Time point:

24/48/72 h

Score:

0

Max. score:

4

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Based on the effects observed with the closely related substance 4 -methylbenzenesulfonic acid, a corrosive property of 4 -hydroxybenzenesulfonic acid has to be assumed. In an incompletely documented Corrositex study (2ndary Literature) a break-through time of 3 -30 Minutes is given for 4 -hydroxybenzenesulfonic acid, which would suggest corrosive properties as well. Additionally, an in vivo rabbit study with the sodium salt of 4 -hydroxybenzenesulfonic acid exists, which does not show irritating properties for the substance, however the concentrations tested were low and the sodium salt was present as neutralized solution, therefore this study is not useful to assess the corrosive properties of the acid.

Justification for classification or non-classification

According to Regulation (EC) 1272/2008 (CLP), Classification as corrosive Cat. 1B (H314) is warranted based on the data available for 4 -methylbenzenesulfonic acid and 4 -hydroxybenzenesulfonic acid. No data on eye damage are available, however according to Regulation (EC) 1272/2008 (CLP), classification for severe eye damage Cat. 1 (H318) is subsequent to classification with H314.