Toluene-4-sulphonic acid

Endpoint summary

Description of key information

The ASA Category comprises the following 5 aromatic sulphonic acids:

TSA, Toluene-4-sulphonic acid (EC 203-180-0, CAS 104-15-4)

XSA, (Xylenes and 4-ethylbenzene) sulphonic acid (EC 701-247-3, CAS -) Former EC 246-839-8

CSA, p-cumene sulphonic acid (EC 240-210-1, CAS 16066-35-6)

BSA, Benzene sulphonic acid (EC 202-638-7, CAS 98-11-3)

HBSA, 4-hydroxybenzensulphonic acid (EC No. 202-691-6, CAS No. 98-67-9)

Skin and eye irritation potential was assessed with available test on ASA substances.

Regarding skin irritation, three tests were available on TSA. The GLP guideline study conducted in 1988 indicated corrosive properties after 4 hours of exposure; and the effects were not reversible after 7 days. 3-minute exposures followed by washing with water resulted in a much less severe effect that was reversible within 72 hours. Two further publications are available on BUA report (1991) which confirm the effect on skin but only some details are available. During the test on sensitisation the primary skin irritation effect of 0.01 -20% solutions of toluene-4-sulphonic acid monohydrate in 0.9% NaCl solution was studied. The animals was exposed 24 hours to an occlusive application. An irritation effect was only found with 20% toluene-4-sulphonic acid , but in a study by Loden et al (1985) with rabbits, without occlusion and after 4 hours, the same concentration in pure water solution caused burns.

Regarding eye irritation, there is only one study available on HBSA. The test was performed in 1962 and is a non-guideline study where a 65% solution hydroxyl benzene sulphonic acid was used as tested item. The results indicated corrosion of the eye even after 5 seconds of exposure. There was no reversibility indicated within 14 days.

All the ASA substance are strong acid with very low pH values. Based on the results of the available studies and due to the similarity among the category members it seems reasonable to consider all the ASA substances as corrosive to the skin and eye.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1988

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: secondary source

Justification for type of information:

The study wasn't focused on irritation since is comprised in a skin sensitization test therefore only some indications can be taken into account to support the end point.

Reason / purpose for cross-reference:

reference to same study

Principles of method if other than guideline:

The test has been done for sensitisation and followed official OECD guideline.

GLP compliance:

yes (incl. QA statement)

Species:

guinea pig

Strain:

Pirbright-Hartley

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

physiological saline

Controls:

not specified

Amount / concentration applied:

0.01-20% solutions of PTSA monohydrate in 0.9% NaCl solution

Duration of treatment / exposure:

24 hours

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

probability of severe irritation

Irritant / corrosive response data:

An irritation effect was only found with 20% PTSA: one clearly defined erithema and a hardly discernible oedema, and a very slight erythema on the second animal

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Irritant

Executive summary:

The skin irritation potential of Toluene 4-sulphonic acid was assessed with the evaluation in a test done for skin sensitisation and followed official OECD guideline. An irritation effect was only found with 20% PTSA: one clearly defined erithema and a hardly discernible oedema, and a very slight erythema on the second animal.

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1985

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Secondary literature reference

Principles of method if other than guideline:

Non occlusive application. Each animal was treated simulteneously at 4 application sites. 2 substances was tested at different concentrations on one animal in order to reduce the risk of any synergistic effects. Four hours exposure

GLP compliance:

no

Species:

rabbit

Type of coverage:

open

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

PTSA monohydrate 0.5-60% aqueous solutions

Duration of treatment / exposure:

4 hours

Details on study design:

In this test with non occlusive application, the animals was treated simulteneously at 4 application sites. 2 substances was tested at different concentrations on one animal in order to reduce the risk of any synergistic effects. In the case of PTSA, the animals were exposed parallely to ethylene diamine, hydrofluoric acid, morpholine, sodium bifluoride, sodium hypochloride or propionic acid.

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Remarks on result:

probability of severe irritation

Irritant / corrosive response data:

Four hours exposure to 0.5% PTSA solution only caused irritation in one of three animals, while concentrations of 20-60% caused necrosis with subsequent scar formation.

Interpretation of results:

Category 1 (corrosive) based on GHS criteria

Conclusions:

Skin Corrosion 1C, H314: Causes severe skin burns and eye damage.

Executive summary:

The skin irritation potential of Toluene 4-sulphonic acid was assessed with a test where each animal was treated simulteneously at 4 application sites. Four hours exposure to 0.5% of the test item solution only caused irritation in one of three animals, while concentrations of 20-60% caused necrosis with subsequent scar formation. 

Reference 3

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Temp: 20 ± 3 °C
Relative humidity: 50 ± 20 %
Light: 12 hours
Food: ad libitum (Altromin 2123 Haultungsdiat supplied by Altromin-Gmbh)
Water: ad libitum tap water

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

physiological saline

Controls:

yes, concurrent no treatment

Duration of treatment / exposure:

4 hour

Observation period:

7 days

Number of animals:

1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

48 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Irritant / corrosive response data:

30-60 minutes after removing the plaster up to the 3rd day post administration, the skin of the animals showed a clearly circumscribed to severe erythema and a noticeable oedema. In addition, the skin surface was partly dry and brittle and flaky or brown over a large area. Hardening and scab formation were also observed. 7 days post administration the skin of the tier showed a clearly circumscribed erythema and a leitches odema. In addition, a dry and brittle skin surface, scab formation, an open wound and the formation of scars were observed.

Other effects:

Mean Edema score was 2.0, Brown discolouration

3 additional animals were exposed for 3 minutes each. The mean erythema score was 0.6 and the mean edema score was 0. Effect was reversible within 72 hours.

Washing immediately after exposure significantly reduced the severity and duration of the effect.

See attached table for details.

Interpretation of results:

Category 1 (corrosive) based on GHS criteria

Conclusions:

Skin Corrosion 1C, H314: Causes severe skin burns and eye damage.

Executive summary:

The skin irritation potential of Toluene 4-sulphonic acid was assessed following official guideline OECD 402, Acute Skin Irritation/Corrosion. The skin of the animals showed a clearly circumscribed to severe erythema and a noticeable oedema. In addition, the skin surface was partly dry and brittle and flaky or brown over a large area. Hardening and scab formation were also observed. The effects were seen after 7 days post administration.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

other: Read across from an analogous substance

Adequacy of study:

key study

Study period:

1962

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

9 animals were exposed to 0.1 mL of the test substance for 5, 10 or 30 seconds (3 animals for each duration) and then eyes were rinsed. The Draize, Woodard and Calvery scoring system was used. Observations were at 1, 4, 24, 48, 72, 120 and 168 hours following exposure. Reversibility was determined up to 14 days post exposure.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Duration of treatment / exposure:

5, 10 or 30 seconds

Observation period (in vivo):

168 hours for scoring and 14 days for reversibility

Number of animals or in vitro replicates:

3 at each treatment duration

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 5 second exposure

Score:

>= 83.6 - < 110

Max. score:

110

Reversibility:

not fully reversible within: 14 days

Remarks on result:

other: overall irritation score was 83.6 out of 110 at 5 second exposure, and 110 out of 110 at both 10 and 30 second exposures

Other effects:

With 5 second exposure there was copious discharge, swelling with lids about half closed, severe redness of conjunctivae, and opacity sufficient to render the iris invisible, all developed within a few minutes. After 14 days there is moderate edema and discharge, moderately severe erythema, and opalescent areas. The iris is reacting to light.
With 10 second exposure, the response was similar to 5 seconds except the iris seems to be destroyed at 14 days. Maximum score of 110 reached in 4 hours.
With 30 second exposure, the response was similar to 10 seconds but with the area of severe edema and congestion extending for a greater distance around the eye.
The cornea became opalescent in 4-8 seconds and the swelling was rapid in all exposures.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

Eye Damage 1, H318: Causes serious eye damage.

Executive summary:

The eye irritation of Hydroxybenzene sulphonic acid was assessed with a test where 9 animals were exposed to 0.1 mL of the test substance for 5, 10 or 30 seconds (3 animals for each duration) and then eyes were rinsed. The Draize, Woodard and Calvery scoring system was used. Observations were at 1, 4, 24, 48, 72, 120 and 168 hours following exposure. Reversibility was determined up to 14 days post exposure. The test substance is corrosive to the eye even with short (i.e., 5-30 second) exposure.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on existing tests the substance is classificated following Regulation (CE) 1272/2008 as: 

-Skin Corrosion 1C, H314: Causes severe skin burns and eye damage.

- Eye Damage 1, H318: Causes serious eye damage.