2-Oxa-7-thia-3,8-disiladecane, 3-methoxy-3,8,8,9,9-pentamethyl-

Skin sensitisation

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: Conducted at GLP-accredited facility to current guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd, Margate, Kent, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 15-23 g
- Housing: individually in suspended solid-floor polypropylene cages with softwood wood flakes
- Diet (e.g. ad libitum): ad lib Certified Rat & Mouse diet
- Water (e.g. ad libitum): ad lib mains tap water
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25
- Humidity (%): 30-70
- Air changes (per hr): approximately 15
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 2 April 2007 To: 2 May 2007

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

25%, 50%, and 100% (undiluted)

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Compound solubility: not applicable, used undiluted
- Irritation: mild redness to head and ears from undiluted material pre and post dose on day 3 and days 4 and 5

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response: at least 3-fold greater increase in 3H thymidine incorporation compared to control
- Lymph node proliferation response: lymph nodes were pooled from all animals in each group prior to the preparation of the cell suspension

TREATMENT PREPARATION AND ADMINISTRATION: mice were administered the test material (25 µl) on the dorsal surface of the ear for three consecutive days, test material formulation was applied with a micropipette and spread over the dorsal surface of the ear using the tip of the pipette

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Statistics:

EC3 value determined using linear regression ( GraphPad Prism software)

Results and discussion

Positive control results:

Historical control data indicate suitable sensitivity and reproducibility of the study as conducted at the laboratory

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

11.55

Test group / Remarks:

100%

Results 2

Parameter:

SI

Value:

7.85

Test group / Remarks:

50%

Results 3

Parameter:

SI

Value:

3.8

Test group / Remarks:

25%

Results 4

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: control: 9651.83 25%: 36716.45 50%: 75750.95 100%: 111511.70

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

The test material was positive (greater than 3 -fold response above control) at all concentrations tested. The EC3 was estimated from linear regression to be 19.3%