2,3,6-trimethylphenol

Endpoint summary

Description of key information

2,3,6-Trimethylphenol is severely irritating to the eye based on the finding of staphyloma and on the severity / irreversibility of observations.

2,3,6-trimethylphenol is a dermal irritant based on signs of irritation observed in 1/2 animals after short-term exposure and on necrosis observed after 20-hour exposure. The signs of irritation / necrosis partially persisted at the end of the 8-day observation period. (Note: the exposure time of 20 hours exceeds the requirement of OECD TG 404.)

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

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented stud report which meets basic scientific principles; pre-GLP study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

2 animals, treatment time: 1, 5, 15 min, 20 hours; onservation after 24 hours and 8 days

Principles of method if other than guideline:

BASF-Test

GLP compliance:

no

Remarks:

pre-GLP study

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

light/dark rhythm: 12/12 hours

Type of coverage:

semiocclusive

Preparation of test site:

not specified

Vehicle:

water

Controls:

other: untreated sites of the same animals

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): no data
- Concentration (if solution): 50% aqueous suspension
No further data

Duration of treatment / exposure:

1 minute, 5 minutes, 15 minutes, 20 hours (dorsal skin)
20 hours (inner auricle)

Observation period:

8 days

Number of animals:

2

Details on study design:

TEST SITE
- Area of exposure: back and ear
- % coverage: no data
- Type of wrap if used: no data

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no data

SCORING SYSTEM:
BASF scores, convertible into Draize scores, readings at 24 hours and 8 days after beginning of application

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 0-8 days

Score:

>= 1 - <= 3

Max. score:

3

Reversibility:

not reversible

Remarks on result:

other: necrosis

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 0-8 days

Score:

0

Max. score:

0

Irritant / corrosive response data:

see table

Draize scores (erythema and edema) and findings:

Site	Exposure  time	24-hour reading		8-day reading
		Animal no. 1	Animal no. 2	Animal no. 1	Animal no. 2
Back	1 min	Erythema: 2	No finding	No finding	No finding
	5 min	Erythema: 2	No finding	No finding	No finding
	15 min	Erythema: 3	Erythema: 1	Slight desquamation	No finding
	20 h	Centre: whitish-anemic Surrounding area: Erythema: 2	Erythema: 2 Necrotic focus (area ca. 1 cm²)	Superficial necrosis	Erythema: 2 Superficial necrosis
Ear	20 h	Erythema: 2 Spotted anemic		Erythema: 2 Superficial necrosis	Encrustation

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Executive summary:

A 50% aqueous preparation applied for up to 20 hours under semiocclusive conditions was irritating to the skin of rabbits.

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

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented study report which meets basic scientific principles; pre-GLP study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

yes

Remarks:

reading after 1,24hours, 8 days, 2 animals

Principles of method if other than guideline:

BASF-Test

GLP compliance:

no

Remarks:

pre-GLP study

Species:

rabbit

Strain:

Vienna White

Details on test animals or tissues and environmental conditions:

dark/light rhythm 12/12 hours

Vehicle:

unchanged (no vehicle)

Controls:

other: talcum

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 1 spoon of the kristalline unchanged substance

Duration of treatment / exposure:

up to 8 days, no substance wash out

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

2

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no

SCORING SYSTEM:
BASF scores, convertible into Draize scores, readings at 24 hours and 8 days after beginning of application

TOOL USED TO ASSESS SCORE: no data

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 0-8 days

Score:

>= 1 - <= 3

Max. score:

3

Reversibility:

not reversible

Remarks on result:

other: staphyloma

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 0-8 days

Score:

>= 0 - <= 1

Max. score:

1

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 0-8 days

Score:

>= 1 - <= 2

Max. score:

2

Reversibility:

not fully reversible within: 8 days

Remarks on result:

other: staphyloma

Irritant / corrosive response data:

see table

Draize scores and findings:

Reading	Animal no	Treated eye					Control eye
		Cornea	Iris	Redness	Edema	Remarks	Redness	Remarks
1 hour	1	1	0	1	3-4	-	2	RS
	2	1	0	1	2	-	2	RS
24 hours	1	3	1	2	2	H	2
	2	3	1	2	2	-	0
8 days	1	3	0	2	0	S, IV	0
	2	3	0	0	0	IV	0

Legend: abbreviations used for remarks

RS = residues of the test substance

H = hemorrhages

S = staphyloma

IV = ingrowing vessels

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Executive summary:

The test substance caused severe damage to the eyes when instilled unchanged into the conjunctival sac of the eye of the rabbits.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Eye irritation

In a primary eye irritation study (BASF, 1969), 0.05 ml bulk volume of unchanged, solid 2,3,6 -trimethylphenol (purity not given) was instilled into the conjunctival sac of one eye of two rabbits without rinsing. Talcum was placed into the other eye for control purpose. Animals then were observed for 8 days. Irritation was scored by an internal BASF method; the scores of which are convertible to the Draize system. In this study, 2,3,6 -trimethylphenol is severely irritating to the eye based on the finding of staphyloma and on the severity / irreversibility of observations. Instillation of the test substance produced corneal opacity (up to grade 3), iritis (grade 1), conjunctivae redness (up to grade 2), chemosis (up to grade 3 -4), hemorrhages, staphyloma and ingrown vessels. The signs of irritation / lesions partially persisted at the end of the 8 -day observation period. In this study, 2,3,6 -Trimethylphenol is severely irritating to the eye based on the finding of staphyloma and on the severity / irreversibility of observations.

Skin irritation

In a primary dermal irritation study (BASF, 1969), two rabbits were dermally exposed to a 50% aqueous suspension of 2,3,6 -trimethylphenol (purity not given) for 1, 5, and 15 minutes (short-term exposure, application to the back). Additionally, the two rabbits were exposed the same suspension for 20 h (long-term exposure; application to the back and ear). Animals then were observed for 8 days. Irritation was scored by an internal BASF method; the scores of which are convertible to the Draize system. Erythema of grade 2 to 3 was reported after application for 1, 5, or 15 minutes for 1/2 animal. Erythema of grade 2 and necrosis was observed in both animals after application for 20 h; the findings were not reversible within 8 days.

2,3,6 -trimethylphenol (no further data) was irritating to the rabbit skin (HRC, 1985). The study is available as secondary citation only, and therefore not assignable at the moment.

 

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes under regulation 1272/2008. 2,3,6 -trimethylphenol has to be classified as corrosive / causing severe damage to the eye Cat. 1 (H318) and as irritating to the skin Cat. 2 (H315).