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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:
2007-10-19 to 2007-11-30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
1992-07-17
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Version / remarks:
96/54/EC
Deviations:
no
Principles of method if other than guideline:
NA
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
This study was available before the implementation of REACH and before the OECD Guideline 429 became mandatory.

Test material

Constituent 1
Chemical structure
Reference substance name:
2-{4'-[difluoro(3,4,5-trifluorophenoxy)methyl]-3',5'-difluoro-[1,1'-biphenyl]-4-yl}-5-ethyloxane
EC Number:
616-651-4
Cas Number:
787582-75-6
Molecular formula:
C26H21F7O2
IUPAC Name:
2-{4'-[difluoro(3,4,5-trifluorophenoxy)methyl]-3',5'-difluoro-[1,1'-biphenyl]-4-yl}-5-ethyloxane

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen
- Females nulliparous and non-pregnant: not specified
- Age at study initiation: about 4 weeks
- Weight at study initiation: 376 to 448 g
- Housing: five per cage
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 to 24
- Humidity (%): 47 to 62
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
paraffin oil
Concentration / amount:
10 g/L
Day(s)/duration:
on day 1
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, occlusive
Vehicle:
polyethylene glycol
Concentration / amount:
200 g/L
Day(s)/duration:
on day 8; 48 hours
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
polyethylene glycol
Concentration / amount:
100 g/L
Day(s)/duration:
on day 22; 24 hours
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
Pretest: 5 females
Group 1: 5 females (negative control group)
Group 2: 10 females (test material group)
Details on study design:
RANGE FINDING TESTS:
The follwoing concentrations were tested in the pre-test to determine the slightly irritating concentration for the dermal induction and to find out the non-irritating challenge concnetration.

1. Test itm in liquid paraffin:
- no pretreatment: intradermal injection: 50, 25, 10, 5, 1, and 0 g/L
2. Test item in PEG 400
- no pretreatment: topical exposure (48 hours): 400, 200, 100, and 50 g/L
- pretreatment with FCA: topical exposure (24 hours): 200, 100, 50, and 10 g/L

MAIN STUDY
A.1 INDUCTION EXPOSURE (intradermal) on day 1
- No. of exposures: three on each side (six)
- Exposure period: NA
- Test groups: FCA + sodium chloride solution, 10 g/L test item ad liquid paraffin, FCA with test item + sodium chloride solution (10 g test material/L preparation)
- Control group: FCA + sodium chloride solution, liquid paraffin, FCA + sodium chloride solution
- Site: shoulder
- Frequency of applications: single
- Duration: NA
- Concentrations: 10 g/L test item

A.2 INDUCTION EXPOSURE (epicutaneous) on day 8
- Exposure period: 48 hours
- Test groups: 200 g/L test item ad PEG 400
- Control group: PEG 400
- Site: shoulder
- Frequency of applications: single
- Duration: NA
- Concentrations: 200 g/L test item

B. CHALLENGE EXPOSURE on day 22
- Day(s) of challenge: on day 22
- Exposure period: 24 hours
- Test groups: 100 g/L ad PEG 400
- Control group: PEG 400
- Site: side
- Concentrations: 100 g/L test material
- Evaluation (hr after challenge): 48 and 72 hours

Challenge controls:
Vehicle polyethylene glycol 400 (PEG 400) only.
Positive control substance(s):
yes
Remarks:
α-Hexylcinnamaldehyde periodically investigated

Results and discussion

Positive control results:
The sensitivity of the test system is only checked periodically with α-Hexylcinnamaldehyde. The data of the latest investigation are provided in the study report. At that time a positive reaction of 50% has been determined after induction.

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
48
Group:
negative control
Dose level:
100 g/L
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
None
Key result
Reading:
1st reading
Hours after challenge:
48
Group:
test chemical
Dose level:
100 g/L
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Key result
Reading:
2nd reading
Hours after challenge:
72
Group:
negative control
Dose level:
100 g/L
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
None
Key result
Reading:
2nd reading
Hours after challenge:
72
Group:
test chemical
Dose level:
100 g/L
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Key result
Reading:
1st reading
Hours after challenge:
48
Group:
positive control
Dose level:
10 g/L
No. with + reactions:
5
Total no. in group:
10
Remarks on result:
positive indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Under the given experimental conditions, the test material induced no reactions. According to CLP, the test item is not to be classified as sensitizer.
Executive summary:

The test item was investigated for skin sensitizing properties in the guinea pig maximization test according to Magnusson and Kligman (1969). A pre-test with intradermal or topical administrations of the vehicles and the test material was performed to select the concentrations suitable for the main study. In the main study, 5 females were treated with the vehicles liquid paraffin (intradermal) and polyethylene glycol 400 (group 1), 10 females were treated with the test material (group 2). Induction included intradermal injection of test material preparation in liquid paraffin (10 g/L with and without Freund's complete adjuvant) on experimental day 1, and topical application of test material preparation in polyethylene gylcol 400 (200 g/L) for 48 hours on experimental day 8. Challenge by topical application of the test material preparation in polyethylene glycol 400 (100 g/L) for 24 hours was performed two weeks after topical induction and readings were taken at 48 and 72 hours after start of the treatment. After intradermal injection, the common signs of irritation after injection of Freund's complete adjuvant were observed. The injection sites were swollen and red with subsequent scab formation. The challenge was performed on the right side of the animals. Group 1 (negative control group): After challenge with polyethylene glycol 400, no erythema or edema was observed. A single treatment was performed with test material (100 g/L preparation in polyethylene glycol 400) to exclude primary irritation of the test material concentration. No positive reactions were observed in the treated areas at any time point. Group 2 (test material group): After challenge with test material (100 g/L preparation in polyethylene gylcol 400) no positive skin reactions were observed. This results in 0 % positive reactions after challenge. After challenge, no positive reactions were observed in the areas treated with polyethylene glycol 400 alone at any time. The clinical behaviour of the guinea pigs was normal during the experimental part and all animals survived. The body weight development corresponded to that of the animals of the vehicle group.