Lanthanum oxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study relatively well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Acute toxicological evaluation of lanthanum oxide

Author:

Lambert C E, Barnum E C, Shapiro R

Year:

1993

Bibliographic source:

Journal of the American College of Toxicology, 12 (6), 622

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: Draize HH, Woodward G, Calveny HO, Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes. J. Pharmacol. Exp. Ther. 83, 377-390, 1944

Principles of method if other than guideline:

0.5 g of the test substance was appied to one intact and one abraded skin site (approx. 2.5 cm2) of six New Zealand White rabbits and occluded for 24 hours. The patches were then removed and the test sited wiped. The sites were evaluated 24 and 72 hours after initial exposure according to the method of Draize.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Lanthanum oxide

EC Number:

215-200-5

EC Name:

Lanthanum oxide

Cas Number:

1312-81-8

Molecular formula:

La2O3

IUPAC Name:

lanthanum(3+);oxygen(2-)

Details on test material:

No data

Test animals

Species:

rabbit

Strain:

New Zealand White

Test system

Type of coverage:

occlusive

Preparation of test site:

other: one shaved, on abraded skin site

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

24 hours

Observation period:

24 and 72 hours after exposure.

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm2
- Type of wrap if used: occluded


REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiping
- Time after start of exposure: 24 hours


SCORING SYSTEM: Draize, 1944

Results and discussion

In vivo

Results

Irritation parameter:

overall irritation score

Remarks:

0.0

Basis:

mean

Time point:

other: 24 and 72 h

Score:

0

Max. score:

8

Reversibility:

other: not applicable as no reaction was observed

Remarks on result:

other: Not irritating

Irritant / corrosive response data:

No signs of irritation were observed. The primary dermal irritation index was 0.0.

Other effects:

Not reported

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Under the conditions of the test, 24 h occluded exposure of intact or abraded skin of 6 rabbits, no signs of irritation were observed. Therfiore the substance can be considered as non-irritant to rabbit skin. It is to be expected that under the conditions of OECD guideline 404 that are less stringent (4 h semiocclusive exposure) no skin irritation will be observed.

Executive summary:

In a primary dermal irritation study (Lambert CE et al, 1993), 6 New Zealand White rabbits were exposed to 0.5 g of the test substance (purity unknown) to intact and abraded skin (2.5 cm2 skin surface covered) for 24 hours under occluded conditions. The animals were observed for 3 days. The irritation was scored by the method of Draize. No signs of irritation were observed 24 or 72 hours after patch removal and wiping off of the test substance. It can be concluded that the test substance is not irritating to rabbit skin and is unlikely to be a human skin irritant.