2-naphthol

Endpoint summary

Description of key information

The in vivo skin irritation/corrosion study of 2-naphthol was determined in accordance with OECD Test Guideline 404 (Acute Dermal Irritation/Corrosion).

 

Test Species New Zealand White Rabbit (approx. 3-5 months old).

 

A patch test was carried out at the dorsal area of the torso after shaving and 500 mg of the test substance was applied per animal for a total exposure time of 4 hours.  Assessments were made after 30 min, 60 min, 24 h, 48 h and 72 h after patch removal.

 

No resulting erythema and no resulting edema were observed at any of the observation time points.

 

Therefore, there was no skin reaction observed within 72 hours and the test item is classified as not irritating to the skin.  

 

The in vivo eye irritation of 2-naphthol was determined in accordance with OECD Testing Guideline 405 (Acute Eye Irritation/Corrosion).

 

Test species: New Zealand White Rabbit

 

100 mg of the test substance 2-naphthol was used on 3 concurrent animals with an observation period of 7 days.

 

1-72 hours after application: conjunctival swelling (Draize scores 2 and 3), grade 2 conjuctivitis, corneal opacity (grade 1) and iritis (grade 1). White discharge. 1 out of 3 animals was free of symptoms after 7 days.  The other two animals showed slight to moderate conjunctivitis, one animal had iritis and white discharge.  Both animals had corneal opacities with vascularization and conjunctivae were partly detached.

 

2-Naphthol induced severe damage to rabbit's eyes in Draize test.  According to the CLP regulation, the test item 2-naphthol was defined as Category 1 "Irreversible effects on the eyes" based on GHS criteria.

 

 

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:

12.08.1986 - 15.08.1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

12.05.1985

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

animal weight: 2,6 - 3,2 kg

animal age: approx. 3 - 5 months

animal keeping: single cages in fully air-conditioned rooms

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

physiological saline

Amount / concentration applied:

500 mg beta-Naphthol per animal

Duration of treatment / exposure:

exposure time: 4 h

Observation period:

The assessments were made after 30 min, 60 min., 24 h, 48 h, and 72 h after patch removal.

Number of animals:

3

Details on study design:

Patch test was carried out at the dorsal area of the torso after shaving.

Irritation parameter:

erythema score

Basis:

animal: 1, 2, 3

Time point:

other: after 30min. and 60 min.

Score:

0

Irritation parameter:

erythema score

Basis:

animal: 1, 2, 3

Time point:

24/48/72 h

Score:

0

Irritation parameter:

edema score

Basis:

animal: 1, 2, 3

Time point:

other: after 30 min. and 60 min.

Score:

0

Irritation parameter:

edema score

Basis:

animal: 1, 2, 3

Time point:

24/48/72 h

Score:

0

Irritant / corrosive response data:

no resulting erythema, no resulting edema

Interpretation of results:

GHS criteria not met

Conclusions:

During the whole test period no irritations for beta-naphthol on New Zealand rabbits were observed. Therefore, 2-Naphthol is classified as not irritating to the skin.

Executive summary:

In a study according to OECD Test No. 404 Acute dermal Irritation/corrosion the skin irritation potential of 2-naphthol was evaluated in New Zealand White rabbits. Application of 500 mg was made onto the intact and shaved skin. There was no skin reaction observed within 72 hours. Therefore, the test item is classified as not irritating to the 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:

experimental study

Adequacy of study:

key study

Study period:

12.08.1986 - 19.08.1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

12.05.1981

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent negative control

Amount / concentration applied:

100 mg per animal

Observation period (in vivo):

7 d

Number of animals or in vitro replicates:

3 concurrent animals

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24 h

Score:

3

Max. score:

4

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

48 h

Score:

2

Max. score:

4

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 7 d

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24 h

Score:

3

Max. score:

4

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

48 h

Score:

2

Max. score:

4

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

fully reversible within: 7 d

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 d

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 7 d

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 7 d

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 7 d

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 7 d

1 - 72 hours after application: conjunctival swelling (Draize scores 2 and 3), grade 2 conjunctivitis, corneal opacity (grade 1) and irits (grade 1). White discharge. 1 out of 3 animals was free of symptoms after 7 days. The other two animals showed slight to moderate conjunctivitis, one animal had iritis and white discharge. Both animals had corneal opacities with vascularization and conjunctivae were partly detached.

Interpretation of results:

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

Remarks:

former R41

Conclusions:

Under experimental conditions of this study, the test item 2-Naphthol induced severe damages to rabbit's eyes in a Draize test according OECD Guideline 405 method. According to CLP regulation, the test item 2-Naphthol was defined as Category 1 "Irreversible effects on the eyes" based on GHS criteria.

Executive summary:

A Draize test according OECD Guideline 405 method was performed to assess the potential irritation/corrosion property of 2-Naphthol.

Under experimental conditions of this study, the test item 2-Naphthol induced severe damages to the rabbits' eyes .

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Justification for classification or non-classification

Skin irritation and eye irritation were investigated in accordance with the relevant OECD Test Guidelines.

2-Naphthol did not result in any erythema or edema during an in vivo skin irritation study.  The test substance does not meet the criteria for classification as irritant to the skin according to Regulation EC No. 1272/2008.

 

2-Naphthol produced severe irreversible damage to rabbit's eyes and was classed as Category 1 eye irritant according to Regulation EC No. 1272/2008.