1-naphthol

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1962

Report date:

1962

Materials and methods

Principles of method if other than guideline:

Method of Draize and associates was used (Draize et al, J. Pharmacol. Exp. Therap., 82: 377 (1944)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-naphthol

EC Number:

201-969-4

EC Name:

1-naphthol

Cas Number:

90-15-3

Molecular formula:

C10H8O

IUPAC Name:

naphthalen-1-ol

Test material form:

solid

Specific details on test material used for the study:

The material was either in commercial production or have been evaluated for commerical potential.

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male

Details on test animals or test system and environmental conditions:

Animals weighed 2.5 to 3.5 kg.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

not specified

Details on dermal exposure:

The fur is removed from the entire trunk by clipping, and the dose is retained beneath an impervious plastic film. Dosages greater than 20ml/kg cannot be applied in contact with the skin.

Duration of exposure:

Animals are immobolized during the 24-hour contact period, after which the film is removed and the rabbits are caged for subsequent 14-day observation period.

Doses:

0.33 to 2.35

No. of animals per sex per dose:

four

Control animals:

not required

Statistics:

The LD50 and its fidutial range are estimated by the method of Thompson (Thompson WR: Use of moving Averages and Interpolation to Estimate Median effective dose. Bacteriol. Rev. 11: 115, 1947) using the Tables of Weil (Weil, GS: Tables for convenient calculation of Median-effective Dose (LD50 or ED50) and Instructions in their use. Biometrics 8: 249, 1952). The (dose) figures in parntheses show limits of +/- 1.96 standard deviations

Results and discussion

Effect levels

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

>= 880 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

Not described

Clinical signs:

other: Not described

Gross pathology:

Not mentioned

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Remarks:

Note: substance has a harmonized classification as Cat 4

Conclusions:

The LD50 was 880 mg/kg in NewZealand male albino rabbits in a 24 hour exposure (occlusive) based on acceptable scientific methods (Draize method for experimental procedures and Thompson's method for LD50 calculations).

Executive summary:

LD50 was calculated to be 880 mg/kg in NewZealand male albino rabbits exposed to 1 -naphthol for 24 hours (occlusive), follwed by a 14-day observation period. Acceptable scientific methods (Draize method for experimental procedures and Thompson's method for LD50 calculations) were used.

Under the conditions of this study, based on the results, this substance is classified as Acute toxicity - dermal, Category 3 according to the UN GHS criteria.