Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-compliant guideline study, available as unpublished report, no restrictions, fully adequate for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): sodium dibutyldithiocarbamate (perkacit SDBC liq-w47%)
- Physical state: clear light yellow liquid
- Analytical purity: 46.20% (concentrated aqueous solution)
- Expiration date of the lot/batch: 19 April 2011 (allocated by NOTOX, 1 year after receipt of the test substance)
- Stability under test conditions: stable
- Storage condition of test material: at room temperature in the dark under nitrogen

In vivo test system

Test animals

Species:
mouse
Strain:
other: CBA-J
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Janvier, Le Genest-Saint-Isle, France
- Age at study initiation: approx. 11 weeks old
- Weight at study initiation: within +/- 20% of the sex mean
- Housing: Individually in labeled Macrolon cages (MI type; height 12.5 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France). Paper (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom) was supplied as cage-enrichment. The paper was removed on Day 1 prior to dosing and was supplied again after scoring of the ears on Day 3.
- Diet: pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.7– 22.9
- Humidity (%): 38-81
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:
dimethylformamide
Concentration:
0, 10, 25 and 50% (of the substance as manufactured, i.e. 46.20% aqueous solution)
No. of animals per dose:
5 females/dose
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: the vehicle was selected based on trial formulations performed at NOTOX and on test substance data supplied by the sponsor
- Irritation: a preliminary irritation study was conducted in order to select the highest test substanceconcentration to be used in the main study. In principle, this concentration should be well tolerated systemically by the animals and may give moderate irritation (maximally grade 2 at the highest concentration.
Two test substance concentrations were tested; a 50% and 100% concentration. The highest concentration was the maximum concentration as required in the test guidelines (undiluted for liquids). After a single application of the test substance, the animal treated at 100% was found dead on Day 1 and no abnormalities were noted at necropsy. After 3 days of treatment, the animal at 50% showed no signs of systemic toxicity and the ears of this animal showed no severe irritation.
- Lymph node proliferation response: not determined

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: Stimulation Index (SI) calculated for each group. If the results indicate a SI ≥ 3, the test substance may be regarded as a skin sensitizer, based on the test guideline and recommendations done by ICCVAM

TREATMENT PREPARATION AND ADMINISTRATION: the dorsal surface of both ears was epidermally treated (25 μL/ear) with the test substance
concentration, at approximately the same time per day. The concentrations were mixed thoroughly using a vortex mixer immediately prior to dosing. The control animals were treated the same as the experimental animals, except that the vehicle was administered instead of the test substance.

TREATMENT PREPARATION AND ADMINISTRATION:
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: 1.1, 2.4 and 7.7 for 10, 25 and 50% test substance concentrations, respectively
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: 847, 929, 2063 and 6559 DPM for 0 (vehicle), 10, 25 and 50% test substance concentrations.

Applicant's summary and conclusion