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Diss Factsheets

Toxicological information

Skin sensitisation

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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:
17 May 2001 - 23 July 2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: Guidance on Safety Assessment of New Cosmetics (Japan Cosmetic Industry Association, technical materials No.92, 1991)
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
An LLNA study was not performed because there is an existing reliable study for skin sensitisation using the Guinea Pig Maximisation test method. Furthermore, the LLNA test method is not considered to be suitable for substances that contain silicon. Please refer to the attached document for further details.

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane
EC Number:
241-867-7
EC Name:
1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane
Cas Number:
17928-28-8
Molecular formula:
C10H30O3Si4
IUPAC Name:
2,2,4,6,6-pentamethyl-4-[(trimethylsilyl)oxy]-3,5-dioxa-2,4,6-trisilaheptane
Test material form:
solid - liquid: suspension

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Ichikawaya Co., Ltd.
- Age at study initiation: 5-6 weeks
- Weight at study initiation: 350-408g
- Housing: Animals were housed individually or in twos in aluminium cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 2 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 55 +/-15
- Air changes (per hr): minimum 10
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal
Vehicle:
olive oil
Concentration / amount:
Induction with test substance: 50% (intradermal)
Re-induction: 50% (topical)
Challenge: 50% or 90% (topical, occluded)
Control animals induction: olive oil
Control animals challenge: 50% or 90% test substance
Positive controls: 0.1% and 1% DNCB solution or non-induced animals 8-% ethanol

Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
olive oil
Concentration / amount:
Induction with test substance: 50% (intradermal)
Re-induction: 50% (topical)
Challenge: 50% or 90% (topical, occluded)
Control animals induction: olive oil
Control animals challenge: 50% or 90% test substance
Positive controls: 0.1% and 1% DNCB solution or non-induced animals 8-% ethanol

No. of animals per dose:
Test (induced animals): 10
Control (non-induced animals): 5
Positive control: 5
Details on study design:
INDUCTION
The day of the first induction was designated as day 0. Six injection points were set in two lines of 3 per row. 0.05mL of the test material was administered intradermally to each injection point, as follows, each injection in duplicate.

The test group was administered 1. Distilled water FCA-emulsion, 2. 50% test substance solution, 3. 50% test substance-FCA emulsion.
The positive control group was administered 1. Distilled water-FCA emulsion, 2. 0.1% DNCB-FCA emulsion, 3. 0.1% DNCB-FCA emulsion
The control group was administered 1. Distilled water-FCA emulsion, 2.Olive oil, 3. Olive oil - FCA emulsion
The positive control (non-induction group) was administered 1. Distilled water - FCA emulsion, 2. 80% ethanol solution, 3. Ethanol - FCA emulsion

On day 6, the induction site was clipped wth an electric hair clipper and 0.1 mL 10% SLS ointment was applied openly for all groups, except positive substance induction group.

On day 7, the SLS ointment was removed with luke warm water. 0.2 mL of 50% test substance solution, 1% DNCB solution, olive oil and 80% ethanol solution was administered to test group, positive control group, test non-induction group and positive control non-induction group skin, respectively. The applied material was spread on a patch, which was attached with adhesive elastic bandage and surgical tape and occluded for 48 hours.

CHALLENGE

On day 23, the challenge site on the flank of animals was clipped of hair. The test substance induction and non-induction groups were applied 50% or 90% test substance on challenge site (10 or 5 animals/each concentration). For positive substance induction and non-induction groups , a 0.1 mL of 0.1% DNCB solution was applied to the challenge site. The materials were spread on a patch, and held in place with adhesive elastic bandage and surgical tape and occluded for 24 hours.

At 24 and 48 hours after patch removal (day 25 and 26), the challenge sites were observed for all groups and skin sensitization potential evaluated for test and positive substances.
Challenge controls:
5 Male guinea pigs served as challenge controls. They were administered olive oil at induction, and challenged with 50% or 90% test substance to parallel treatment of the test group.
Positive control substance(s):
yes
Remarks:
2,4-dinitrochlorobenzene

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
90%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
90%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
90%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
90%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
other: 1st/2nd reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1% DNCB
No. with + reactions:
5
Total no. in group:
5
Remarks on result:
positive indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test material was found not to be sensitizing to skin in this guinea-pig Maximization test, conducted according to a protocol equivalent to OECD guideline but not in compliance with GLP.