4-ethylphenol

Endpoint summary

Description of key information

Skin irritation read-across: In a dermal irritation study with rabbits the skin irritation potential of 4-ethynylphenol was investigated. 4-Ethynylphenol caused only a slight skin irritation with very slight to slight erythema. Since a read across from 4-ethynylphenol to 4-ethylphenol is appropriate due to expected comparable toxicological properties, similar skin irritation properties can be expected for 4-ethylphenol. According to classification criteria outlined in Regulation (EC) No 1272/2008, 4-ethylphenol is therefore not to be classified with respect to acute dermal toxicity.

Eye irritation read-across: In an eye irritation study with rabbits the eye irritation potential of 4-ethynylphenol was investigated. 24 h after administration of 0.1 ml all animal showed a moderate to serve conjunctival irritation, iritis and corneal opacity. The severe eye irritation was still present at the end of the observation period seven days after exposure. Therefore, 4-Ethynylphenol is supposed to be highly irritating to eyes. Since a read across from 4-ethynylphenol to 4-ethylphenol is appropriate due to expected comparable toxicological properties, similar eye irritation properties can be expected for 4-ethylphenol.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Study period:

March 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Justification for read-across: see attachment

Reason / purpose for cross-reference:

read-across source

Remarks:

Ethynylphenol

Qualifier:

no guideline followed

Principles of method if other than guideline:

Skin irritation Test (24h exposure on abraded skin) - no further details reported

GLP compliance:

not specified

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

no further details stated in the report

Type of coverage:

not specified

Preparation of test site:

abraded

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

24 h

Observation period:

min. 72 h, no further details stated in the report

Number of animals:

4

Details on study design:

Test material was removed with acetone after 24h.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

72 h

Score:

1

Reversibility:

not specified

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

72 h

Score:

1

Reversibility:

not specified

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

72 h

Score:

2

Reversibility:

not specified

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

72 h

Score:

2

Reversibility:

not specified

Irritation parameter:

edema score

Basis:

animal #1

Time point:

72 h

Score:

0

Irritation parameter:

edema score

Basis:

animal #2

Time point:

72 h

Score:

0

Irritation parameter:

edema score

Basis:

animal #3

Time point:

72 h

Score:

1

Reversibility:

not specified

Irritation parameter:

edema score

Basis:

animal #4

Time point:

72 h

Score:

0

Irritant / corrosive response data:

C-979 produced slight dermal irritation. Two of the four animals exhibited very slight (barely perceptable) erythema witnout edema. Two animals exhibited slight erythema with or without edema.

Other effects:

Not reported.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the 4-ethynylphenol is considered to be slightly irritating to rabbit skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Study period:

April 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Justification for read-across: see attachment

Reason / purpose for cross-reference:

read-across source

Remarks:

Ethynylphenol

Qualifier:

no guideline followed

Principles of method if other than guideline:

Eye Irritation Test (0.1 mL, eyes not rinsed) - no further details reported

GLP compliance:

not specified

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

no further details stated in the report

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.1 mL

Duration of treatment / exposure:

not rinsed

Observation period (in vivo):

7 d

Number of animals or in vitro replicates:

4

Details on study design:

no further details stated in the report

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24 h

Score:

2

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

iris score

Basis:

mean

Time point:

24 h

Score:

1.75

Reversibility:

fully reversible within: 7 d

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Time point:

24 h

Score:

1.25

Reversibility:

fully reversible within: 7 d

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24 h

Score:

3

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

7 d

Score:

3.25

Irritation parameter:

chemosis score

Basis:

mean

Time point:

7 d

Score:

0.25

Irritant / corrosive response data:

C-979 produced severe ocular irritation.
All four animals exhibited moderate to severe conjunctival irritation (redness, chemosis, discharge, necrosis), iritis and corneal opacity, stippling and ulceration, at 24 h.
By Day 7, severe irritation was still evident in all animals.

Other effects:

One animal exhibited a constricted pupil at 24 hours; two animals exhibited pannus (neovascularization of the corneal surface) at Day 7; one animal exhibited hair loss around the eye at Day 7.

Interpretation of results:

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

Conclusions:

Under the conditions of this study, the 4-ethynylphenol is considered to be highly irritating to rabbit eyes.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Justification for classification or non-classification

Based on information available for a read-across chemical, 4-ethylphenol is not to be classified according to Regulation (EC) No 1272/2008 in terms of skin irritation.

Based on information available for a read-across chemical, 4-ethylphenol is considered to meet the classification criteria for Eye damage 1, “Causes serious eye damage” (H318).