(tert-butoxymethyl)oxirane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

THE PERFORMANCE OF THE LOCAL LYMPH NODE ASSAY WITH CHEMICALS IDENTIFIED AS CONTACT ALLERGENS IN THE HUMAN MAXIMIZATION TEST

Author:

Basketter D.A. et al.

Year:

1993

Bibliographic source:

Food Chem Toxicol 32, 543-547

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Principles of method if other than guideline:

- Principle of test: Measuring proliferation of lymphocytes in the lymph nodes draining the site of the test substance application
- Short description of test conditions: Groups of mice (n= 4) were treated by daily topical application for 3 consecutive days with 25 µL of one of three concentrations of the test chemical on the dorsum of each ear. Control mice were treated with vehicle alone in an identical manner. 5 days after the first topical application, all mice were injected i.v. with 250 µL phosphate buffered saline (PBS) containing 20 µCi of [3H]methyl thymidine (3HTdR). The mice were killed 5 hr later and the draining auricular lymph nodes excised and pooled for each experimental group. The proliferative response of the lymph node cells were measured by p-scintillation counting
- Parameters analysed / observed: T:C ratio (which is equal to SI value)

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

(tert-butoxymethyl)oxirane

EC Number:

231-640-0

EC Name:

(tert-butoxymethyl)oxirane

Cas Number:

7665-72-7

Molecular formula:

C7H14O2

IUPAC Name:

2-[(tert-butoxy)methyl]oxirane

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Aldrich Chemical Co., Gillingham, Dorset, UK

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Females (if applicable) nulliparous and non-pregnant: Not specified
- Age at study initiation: 8 - 12 weeks

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

10.0%, 25.0%, 50.0%

No. of animals per dose:

4 animals per goup. One animal per dose including a control animal.

Details on study design:

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local lymph node assay
- Criteria used to consider a positive response: Chemical was regarded as a sensitizer in the LLNA if at least one concentration resulted in a T:C ratio (which is equal to SI value) of 3 or greater and the data were not incompatible with a biological dose response

TREATMENT PREPARATION AND ADMINISTRATION: Mice were treated by daily topical application for 3 consecutive days with 25 µL of one of three concentrations of the test chemical on the dorsum of each ear.

Positive control substance(s):

not specified

Results and discussion

Positive control results:

Not specified

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1.4

Test group / Remarks:

Animal 1/ 10% concentration

Results 2

Parameter:

SI

Value:

2.2

Test group / Remarks:

Animal 2/ 25.0% concentration

Results 3

Parameter:

SI

Value:

5.6

Test group / Remarks:

Animal 3/ 50.0% concentration

Cellular proliferation data / Observations:

The T:C ratio (which is equal to SI value) of the test item as compared to the vehicle was found to be 1.4/2.2/5.6 for test concentrations of 10.0%, 25.0%,50.0% respectively, which is. Since the ratio was > 3 for one of the concentrations, the test item was considered to be a skin sensitizer.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

In this study, the test item is considered to be a skin sensitizer.

Executive summary:

In a an in vivo skin sensitization study conducted similar to OECD 429 with 1-tert-butoxy-2,3-epoxypropane in acetone/olive oil (4:1 v/v), four female CBA/Ca mice were tested using the method of the local lymph node assay by measuring the T:C ratio (which is equal to SI value). The T:C ratio of the test item was found to be 1.4, 2.2 and 5.6 for each concentration respectively. Since the ratio was > 3 for one of the concentrations, 1 -tert-butoxy-2,3-epoxypropane is considered to be a skin sensitizer.