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Administrative data

Description of key information

No skin sensitisation in guinea pigs was observed in a study conducted according to current OECD guideline and under GLP (BSL Bioservice, 2013c).

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:
21st November 2012 to 1st February 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
Buehler test
Justification for non-LLNA method:
An LLNA study was not performed because the 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:
Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River
- Age at study initiation: 4-6 weeks
- Weight at study initiation: 364-440g
- Housing: In groups in Terluran cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: At least five days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 ±3
- Humidity (%): 55 ±10
- Air changes (per hr): At least 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 27-11-2012 To: 01-02-2013
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5g of 100% test substance
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5g of 100% test substance
No. of animals per dose:
Test group: 20
Negative control group: 10
Details on study design:
RANGE FINDING TESTS: Two animals were treated topically with concentrations of 50% and 100% of the test substance (suspended in vaseline) for six hours. A dry patch served as a negative control. Based on the results of this preliminary test a concentration of 100% was chosen for the induction and challenge phases of the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
The left flank was cleared of hair, by close clipping, prior to the first application and again prior to further applications.

The test substance was loaded with 0.5g of the test substance. The patch was applied to the test area of approximately 2.5 x 2.5cm and was held in place by an occlusive dressing for six hours. The procedure was repeated once per week at the same test area at weekly intervals for a total of three weeks. In the negative control group, a dry gauze patch was applied to the test area under the same conditions as the test group.

B. CHALLENGE EXPOSURE
Both flanks were cleared of hair, by close clipping, prior to the challenge application.

13 days after the last induction application the test substance was applied to an area of approximately 2.5 x 2.5cm on the right flank and was held in contact with an occlusive dressing for six hours. A dry gauze patch was applied to an area of approximately 2.5 x 2.5cm on the left flank (intraspecies control) and was held in contact with an occlusive dressing for six hours.

Approximately 21 hours after removing the patch, the challenge area was cleaned and cleared of hair by the use of a depilatory cream. Approximately 24 and 48 hours after removing the patch the skin reaction was observed and recorded. Additionally, all animals were observed for signs of toxicity at least once daily during the test period.
Challenge controls:
Dry patch
Positive control substance(s):
yes
Remarks:
mercaptobenzothiazole
Positive control results:
The sensitisation rate after application of the positive-control substance (25% in vaseline) was 20% confirming the reliability of the test system.
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
None
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
None
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
Dry patch
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
Dry patch
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
25% in vaseline
No. with + reactions:
4
Total no. in group:
20
Remarks on result:
other: The sensitisation rate after application of the positive-control substance (25% in vaseline) was 20% confirming the reliability of the test system.
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
25% in vaseline
No. with + reactions:
4
Total no. in group:
20
Remarks on result:
other: The sensitisation rate after application of the positive-control substance (25% in vaseline) was 20% confirming the reliability of the test system.

The body weight gains of all animals were normal, when compared with the historical data.

Interpretation of results:
GHS criteria not met
Conclusions:
In a skin sensitisation study (Buehler study) conducted to OECD 406 and to GLP (reliability score 1) 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl)cyclotrisiloxane did not cause a positive reaction in any of the guinea pigs tested, and therefore under the conditions of this study is not a skin sensitizer.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

In a skin sensitisation study (Buehler study) conducted to OECD 406 and to GLP, 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl)cyclotrisiloxane did not cause a positive reaction in any of the guinea pigs tested. The negative and positive control (mercaptobenzothiazole) gave appropriate results. Therefore, under the conditions of this study 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl)cyclotrisiloxane is not a skin sensitizer (BSL Bioservice, 2013c).


Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the skin sensitisation study, 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl)cyclotrisiloxane is not classified for skin sensitisation in accordance with Regulation (EC) No 1272/2008.