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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
23.03.1993 to 03.05.1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP. However, the induction concentration was reduced to non irritating half way through the induction phase for which reason reliability 2 is assigned to the study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report date:
1993

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Principles of method if other than guideline:
The concentration was reduced from 100% to 50% for induction phase due to irritation.
GLP compliance:
yes (incl. QA statement)
Type of study:
Buehler test

Test material

Constituent 1
Chemical structure
Reference substance name:
Trimethoxy(2-methylpropyl)silane
EC Number:
242-272-5
EC Name:
Trimethoxy(2-methylpropyl)silane
Cas Number:
18395-30-7
Molecular formula:
C7H18O3Si
IUPAC Name:
trimethoxy(2-methylpropyl)silane
Details on test material:
- Name of test material (as cited in study report): Dynasylan IBTMO (isobutyltrimethoxysilan)
- Substance type: Alkoxysilane
- Physical state: Liquid
- Stability under test conditions: < 1 year
- Storage condition of test material: Protected from humidity

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Fa. Winkelmann
- Age at study initiation: 'young'
- Weight at study initiation: 360-445 g
- Housing: Conventional Type IV Makrolon cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Minimum of five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ±3
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 23.03.1993 to 03.05.1993

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
Induction phase I: 100% test substance, reduced to 50% test substance on day 7 of the induction phase.
Induction phase II and III and challenge: 50% test substance in corn oil.
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
Induction phase I: 100% test substance, reduced to 50% test substance on day 7 of the induction phase.
Induction phase II and III and challenge: 50% test substance in corn oil.
No. of animals per dose:
Test group: 20. Control group: 10.
Details on study design:
RANGE FINDING TESTS: A preliminary study was conducted to determine a non-irritant concentration for the induction and challenge phases of the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Three
- Test groups: one
- Control group: Induction Phases I-III vehicle (corn oil) only applied to left flank.
- Site: Left flank
- Frequency of applications: Day 0, Day 7 and Day 14
- Duration: 6 hours
- Concentrations: Phase I used undiluted, and Phase II and III used 50% in corn oil.


B. CHALLENGE EXPOSURE
- No. of exposures: One
- Day(s) of challenge: Day 28
- Exposure period: 6 hours
- Test and control groups: both treated with 50% test substance
- Site: Right flank
- Concentrations: 50%
- Evaluation (hr after challenge): 6, 24, 48 and 72 hours
Challenge controls:
Treated with 50% test substance.
Positive control substance(s):
yes
Remarks:
1-chloro-2,4,-dinitrobenzol

Study design: in vivo (LLNA)

Statistics:
No data

Results and discussion

Positive control results:
No positive controls.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
other: 1st and 2nd readings
Group:
test chemical
Dose level:
All
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No animals showed a positive reaction
Remarks on result:
other: Reading: other: 1st and 2nd readings. Group: test group. Dose level: All. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No animals showed a positive reaction.
Reading:
other: 1st and 2nd readings
Group:
negative control
Dose level:
All
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No animals gave a positive result.
Remarks on result:
other: Reading: other: 1st and 2nd readings. Group: negative control. Dose level: All. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No animals gave a positive result..

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
In a skin sensitisation study (reliability score 1) conducted according to OECD 406 and to GLP, Dynasylan IBTMO (isobutyltrimethoxysilane) was not sensitising to the skin of Dunkin-Hartley guinea-pigs. There were no systemic effects reported.
Executive summary:

Dynasylan IBTMO (isobutyltrimethoxysilane) was tested in a traditional Buehler skin sensitisation study, to GLP. Twenty Dunkin-Hartley guinea-pigs were exposed to three separate induction phases on their shaved left flanks. On Day 0 undiluted test substance was applied under an occlusive patch for six hours. On Day 7 this process was repeated with a 50% solution in corn oil. On Day 14 the process was repeated again with a 50% solution in corn oil. After each application the skin was monitored for reactions. Ten negative controls had patches with corn oil only applied to their left flanks. On Day 28 both negative controls and test animals had an occlusive patch of 50% test substance (in corn oil) applied to their right flanks. After six hours the dressings were removed and the areas wiped with corn oil. The skin was then assessed at 6, 24, 48 and 72 hours after administration. There were no skin reactions in any of the test or negative control animals during the challenge phase. The test substance was not a skin sensitiser.