Pyrocatechol

Endpoint summary

Description of key information

Catechol was found irritating to skin and inducing severe dammage to eyes in Draize tests. 

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The purity of the test substance is unknown. Exposure duration was 24 h instead of 4 h. Observations were evaluated according to the scoring of Draize.

Qualifier:

according to guideline

Guideline:

other: Draize test

Deviations:

not specified

Principles of method if other than guideline:

Federal register (1961) pp.7333-7341, Part 191- Hazardous Substances: definitions and Procedural and Interpretative Regulations, Final Order. Scoring performed according to Draize.

GLP compliance:

no

Species:

rabbit

Strain:

other: albino

Details on test animals or test system and environmental conditions:

No data

Type of coverage:

not specified

Preparation of test site:

other: intact and abraded skin

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 mg of catechol on bellies of rabbits.

Duration of treatment / exposure:

24 hour(s)

Observation period:

14 days

Number of animals:

6

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 and 72 hours

Score:

5.5

Max. score:

32

Reversibility:

other: see results

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24 and 72 hours

Score:

1.95

Reversibility:

other: see results

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24 and 72 hours

Score:

1.7

Reversibility:

other: see results

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

animal #4

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

animal #5

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritation parameter:

edema score

Basis:

animal #6

Time point:

other: 24 and 72 hours

Reversibility:

not specified

Remarks on result:

other: no individual data

Irritant / corrosive response data:

- Intact skin:
The contact of catechol produced slight to moderate erythema (score 2.2) and slight oedema (score 1.2) after 24 h. 
The irritation was less marked 72 h after exposure (erythema: 1.7 and oedema: 1.0) . 
After 14 days, the intact areas were free of irritation.

- Abraded skin:
The contact of catechol produced necrosis after 24 h. After 14 days, the necrotic areas were incrusted and beginning to slough.

Primary Irritation scores, Intact and abraded skin on rabbits (0.5 g, 24h period):

	Erythema		Edema
	Intact	Abraded	Intact	Abraded
24 hours	2.2	4	1.2	4
72 hours	1.7	4	1	4
Total	3.9	8	2.2	8

Primary Irritation score: 5.5

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Catechol causes skin irritation in EU GHS.

Executive summary:

In a primary dermal irritation study (Flickinger, 1976), 6 albino rabbits were dermally exposed to 0.5 mg of Catechol for 24 hours to bellies. No indication was done concerning dressing. Skin of animals was abraded or intact. Animals then were observed for 14 days. Irritation was scored by the method of Draize.

 

The contact of catechol produced slight to moderate erythema (score 2.2) and slight oedema (score 1.2) after 24 hours on intact skin.

The irritation was less marked 72 h after exposure (erythema: 1.7 and oedema: 1.0).

In this study, Catechol is irritating to the skin based on Draize scoring.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The purity of the test substance is not known.

Qualifier:

equivalent or similar to guideline

Guideline:

other: Draize test

Deviations:

not specified

Principles of method if other than guideline:

Federal register (1961) pp.7333-7341, Part 191- Hazardous Substances: definitions and Procedural and Interpretative Regulations, Final Order .

GLP compliance:

no

Species:

rabbit

Strain:

other: albino

Details on test animals or tissues and environmental conditions:

- Sex: male
- Age: Unknown
No more data

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Amount: 0.1 g

Observation period (in vivo):

14 days

Number of animals or in vitro replicates:

6

Details on study design:

The resultant total eye irritation score were evaluated after 24, 48 and 72 hours.
No more data.

Irritation parameter:

overall irritation score

Basis:

other: Total eye irritation evaluation

Time point:

24/48/72 h

Score:

78 - 103

Max. score:

110

Reversibility:

not reversible

Remarks on result:

other: No individual data.

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not reversible

Remarks on result:

other: No score for cornea opacity has been given. Only the overall irritation score is provided since the study was performed in 1976.

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not reversible

Remarks on result:

other: No score for iris has been given. Only the overall irritation score is provided since the study was performed in 1976.

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not reversible

Remarks on result:

other: No score for conjunctivae has been given. Only the overall irritation score is provided since the study was performed in 1976.

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Reversibility:

not reversible

Remarks on result:

other: No score for chemosis has been given. Only the overall irritation score is provided since the study was performed in 1976.

Irritant / corrosive response data:

- 24 h (score = 103): following exposure showed a diffuse deep-crimson red conjunctivitis with individual vessels not easily discernible, swelling with the lids half closed, severe discharge, iritis, and dense corneal opacities in all of the six exposed eyes.
- 48 h (score = 85): the treated eyes remained relatively unchanged.
- 72 h (score = 78): severe conjunctivitis, iritis and diffuse corneal opacities persisted in all of the exposed eyes.
-14 d: all the treated eyes revealed pannus formations and keratoconnus.
- No information regarding the reversibility within 21 days.

Other effects:

Upon application, the conjunctivae became moderately erythematous and oedematous, and moderate exudate and corneal opacity were produced. Signs of marked discomfort were evident and the effects are not fully reversible within 14 days.  No information regarding the reversibility within 21 days.

Interpretation of results:

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

Remarks:

Based on the results and since there is no reversibility.

Conclusions:

Catechol causes serious eye damage in EU GHS.

Executive summary:

In a primary eye irritation study (Flickinger, 1976), 0.1 mg of Catechol was instilled into the conjunctival sac of one eye of 6 male albino rabbits. Animals then were observed for 14 days. Irritation was scored by the method of Draize.

Upon application, the conjunctivae became moderately erythematous and oedematous, and moderate exudate and corneal opacity were produced. Signs of marked discomfort were evident. After 14 days of observation, all the treated eyes revealed pannus formations and keratoconnus.

The total evaluation varied from 103 to 78 at 24 to 72 hours.

Based on these results, Catechol causes serious damage to eyes.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Additional information

Skin irritation:

Two studies were available. One of them was selected as key study and had reliability 2, the other one was selected as supporting study and had reliability 3. The summary of the key study is the following:

In a primary dermal irritation study (Flickinger, 1976), 6 albino rabbits were exposed by dermal route to 0.5 mg of catechol for 24 hours to bellies. No indication was done concerning dressing. Skin of animals was abraded or intact. Animals then were observed for 14 days. Irritation was scored by the method of Draize. The contact of catechol produced slight to moderate erythema (score 2.2) and slight oedema (score 1.2) after 24 hours on intact skin. The irritation was less marked 72 h after exposure (erythema: 1.7 and oedema: 1.0).

 

 

Eye irritation:

Only one study was available and was selected as key study and had reliability 2. The summary of this key study is the following:

In a primary eye irritation study (Flickinger, 1976), 0.1 mg of Catechol was instilled into the conjunctive sac of one eye of 6 male albino rabbits. Animals then were observed for 14 days. Irritation was scored by the method of Draize. Upon application, the conjunctivae became moderately erythematous and oedematous, and moderate exudate and corneal opacity were produced. Signs of marked discomfort were evident. The total evaluation varied from 103 to 78 at 24 to 72 hours.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: highly irritating/severe dammage

Justification for classification or non-classification

Catechol is irritating to the skin based on Draize scoring. According to classification criteria of EC regulation 1272/2008 and current EC regulation in Annex VI, table 3 (13th ATP), the catechol is classified as irritant for the skin category 2 (H315: Causes skin irritation)

Catechol is highly irritating to eyes, based on the study available. In the current EC regulation in Annex VI, table 3 (13th ATP), the catechol is classified as irritant for the eye category 2 (H319: Causes serious eye irritation) but it should be classified as eye category 1 (H318: Causes serious eye damage) based on the available data.