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Description of key information

The key skin sensitisation study is a guinea pig Bühler, non-adjuvant study in which a delayed contact hypersensitivity response was not elicited. The study was conducted according to OECD Test Guideline 406 and in compliance with GLP (Hüls, 1979e, reliability 1).

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:
Pretest: 1997-04-06 to 1997-04-09; main test: 1997-04-15 to 1997-05-16
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
1992
GLP compliance:
yes (incl. QA statement)
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/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.
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Gartenstraße 27, 33176 Borchen
- Age at study initiation: no information
- Weight at study initiation: less than 50 g
- Housing: conventional, maximum of 5 animals per Macrolon cage - Type IV. Bedding: softwood shavings.
- Diet: Ssniff G4, complete diet for guinea pigs ad libitum
- Water: tap water ad libitum
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30-70%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: To: 16 May 1997
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
Pretest: 5, 25% and 50% solutions in corn oil, and undiluted; induction: undiluted; challenge: 50%
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
Pretest: 5, 25% and 50% solutions in corn oil, and undiluted; induction: undiluted; challenge: 50%
No. of animals per dose:
Three
Details on study design:
RANGE FINDING TESTS: 0.03 cm² of test substance was applied as 5%, 25% and 50% solutions in corn oil and in undiluted form to gauze pads (2 x 2 cm) which were applied to flank skin which had been shaved 2-3 hours earlier. Each pad was covered with an occlusive bandage and then another bandage for six hours. Each of the three animals had two gauze pads on each side. After removal of the patch the application sites were wiped with corn oil and cellulose. Dermal reactions were evaluated 30 and 54 hours after application. In the fourth week of the test, 3 additional untreated guinea pigs were used to determine the maximum, non-irritant concentration to be used in the challenge treatment.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Three
- Exposure period: six hours at weekly intervals (day 0, day 7 and day 14).
- Test groups: 20 animals
- Control group: 10 animals
- Site: left flank
- Frequency of applications: weekly
- Concentrations: 100% test substance

B. CHALLENGE EXPOSURE
- No. of exposures: One
- Day(s) of challenge: Day 28
- Exposure period: six hours
- Test groups: 20 animals
- Control group: 10 animals
- Site: right flank
- Concentrations: 50% test substance
- Evaluation (hr after challenge): 30 and 54 hours after beginning of application
Challenge controls:
The sensitivity of the guinea pig breed used for the sensitisation test was monitored in regularly established time intervals; the last sensitivity test was carried out from 25 November to 20 December 1996 using the Magnusson-Kligman maximisation test using adjuvant.
Positive control substance(s):
yes
Remarks:
2-mercaptobenzothiazole
Positive control results:
100% of the ten test animals showed a sensitisation reaction at 48 and 72 hours after challenge. None of the control animals showed evidence of sensitisation.
Key result
Reading:
other: Evaluation 30 hours after induction phases I, II and III, and 30 h and 54 hours after challenge
Hours after challenge:
30
Group:
test chemical
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No systemic effects or effects on normal body weight development were observed
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
other: Evaluation 30 hours after induction phases I, II and III, and 30 h and 54 hours after challenge
Hours after challenge:
30
Group:
negative control
Dose level:
0
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
other: evaluation of the trigger treatment (50%) was done at 48 and 72 hours after induction with 1.0% 2-Mercaptobenzothiazole in corn oil via intracutaneous injection
Hours after challenge:
48
Group:
positive control
Dose level:
50%
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Erythema and scale formation, swelling. Control group (n=5): no reaction
Remarks on result:
positive indication of skin sensitisation
Remarks:
Test conducted 25 Nov. to 20 Dec. 1996
Interpretation of results:
GHS criteria not met
Conclusions:
In a skin sensitisation study, conducted according to an appropriate OECD test guideline 406, and in compliance with GLP, the test substance, [2-(perfluorohexyl)ethyl]triethoxysilane, was reported to be not sensitising to guinea pig skin.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

[2-(Perfluorohexyl)ethyl]triethoxysilane has been tested for sensitisation in guinea pigs using the Bühler method in a study conducted according to OECD TG 406 and in compliance with GLP (Hüls, 1997e, reliability 1). After the induction phase of three weekly occlusive applications of undiluted test substance, the animals were challenged with a 50% solution of test substance in corn oil. Observations were made at 30 and 54 hours after the challenge. No sensitisation reactions were observed in any of the 20 test animals or the 10 negative control animals. It is concluded that the test substance is not sensitising under the conditions of the test.


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the available studies on skin sensitisation, [2-(perfluorohexyl)ethyl]triethoxysilane does not require classification for sensitisation according to Regulation (EC) 1272/2008.