Registration Dossier

Administrative data

Description of key information

Based on a non-adjuvant sensitisation test in guinea pigs conducted according to an OECD Test Guideline 406 and in compliance with GLP, the test item was found not sensitising to guinea-pig skin (Degussa 2007).

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
An LLNA study was not performed because there is an existing reliable study for skin sensitisation using the Buehler 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.
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River laboratories, Kissleg, Germany
- Age at study initiation:
- Weight at study initiation:
- Housing: 2 or 3 animals per cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): 8
- Photoperiod (hrs dark / hrs light): 12/12

Route:
epicutaneous, occlusive
Vehicle:
other: sesame oil
Concentration / amount:
Induction: undiluted test substance
Challenge: 60% (w/w) dilution in sesame oil
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: sesame oil
Concentration / amount:
Induction: undiluted test substance
Challenge: 60% (w/w) dilution in sesame oil
No. of animals per dose:
Test group: 20
Control group: 10
Pilot experiment: 8
Details on study design:
RANGE FINDING TESTS: Induction and challenge employed DUhring chambers with soaked patches either with 40%, 60% or 80% (w/w) of the test substance diluted in sesame oil or the undiluted test substance (100%).

MAIN STUDY
A. INDUCTION EXPOSURE
24 hours before application the skin on the left flank of the animals had been shorn over an area of approximately 4 cm x 6 cm. A Duhring chamber was filled with a patch of 2 cm x 2 cm size with undiluted test substance and applied to the left flank of each animal of the test group. The chambers were fixed. The animals of the control group were treated similarly, with the exception that they received only the vehicle (sesame oil) instead of the test substance. The dressing was removed after 6 hours, the skin was cleaned with warm water and the reactions observed were classified.

B. CHALLENGE EXPOSURE
The challenge application was carried out on control and test group animals 2 weeks (corresponding to day 28 of the application period) after the last dermal induction. Areas of 4 cm x 6 cm on both flanks of the animals were shorn 24 hours before application. Duhring chambers were filled with patches with the 60% (w/w) dilution of the test substance in sesame oil and were laid on the untreated right flank and fixed. After 6 hours the dressing was removed and the skin was cleaned with warm water. After a further 21 hours after removal of the patches the skin was shorn. Three hours later ( = 24 hours after patch removal) the skin reaction was assessed. The assessment was repeated after a further 24 hours.
Challenge controls:
Challenge controls were included and showed no signs of irritation or sensitisation.
Positive control substance(s):
yes
Remarks:
2-mercaptobenzothiazole
Reading:
other: Induction
Hours after challenge:
6
Group:
test chemical
Dose level:
undiluted
No. with + reactions:
18
Total no. in group:
20
Clinical observations:
Induction was conducted 3 consecutive times; by the last induction most of the animals showed signs of irritation.
Remarks on result:
not determinable
Reading:
other: induction
Hours after challenge:
6
Group:
negative control
Dose level:
vehicle
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No skin reactions.
Remarks on result:
not determinable
Key result
Reading:
rechallenge
Hours after challenge:
24
Group:
test chemical
Dose level:
60% (w/w) in sesame oil
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No skin reactions.
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
rechallenge
Hours after challenge:
24
Group:
negative control
Dose level:
60% (w/w) in sesame oil
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No skin reactions.
Remarks on result:
no indication of skin sensitisation
Key result
Group:
positive control
Remarks on result:
other: positive control was not included
Interpretation of results:
GHS criteria not met
Conclusions:
Based on a non-adjuvant sensitisation test in guinea pigs conducted according to an OECD Test Guideline 406 and in compliance with GLP, the test item was found not sensitising to guinea-pig skin in accordance with current regulation (EC) No 1272/2008.
Executive summary:

No unusual findings were observed , and the body weight development of the animals was positive and within normal ranges. In the challenge no visibile changes to the treated skin sites were observed; there was no positive challenge result in all test group animals.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

No symptoms of systemic toxicity nor unusual findings were observed at any time during a reliable study conducted according to OECD Test Guideline 406 and in compliance with GLP. Body weight development of the animals was positive and within normal ranges. In the challenge test no visibile changes (no erythem nor edema) to the treated skin sites were observed; there was no positive challenge result in any of the test group animals (Degussa, 2007)


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the available information, no classification is required for sensitisation for 3-(triethoxysilyl)propanethiol in accordance with Regulation (EC) No 1272/2008.