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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:
2012-06-28- 2012-11-13
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: well documented GLP-Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
Buehler test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: viscous liquid
Details on test material:
- Name of test material (as cited in study report):
- Physical state: tan viscous liquid
- Analytical purity: 100 %
- Lot/batch No.:
- Expiration date of the lot/batch: 18 Jun 2013
- Storage condition of test material: kept in a controlled room temperature area, protected from light

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, St. Constant, Quebec, Canada
- Age at study initiation: see below
- Weight at study initiation: see below
- Housing: animals were paired housed throughout the study in solid bottom cages containing direct bedding material
- Diet (e.g. ad libitum): PMI Nutrition International Certified Guinea Pig Chow® #5026 was provided ad libitum throughout the study.
- Water (e.g. ad libitum): Municipal tap water following treatment by reverse osmosis and ultraviolet irradiation was available ad libitum throughout the study
- Acclimation period: at least 5 days before the first day of dosing

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 68ºF to 79ºF (20ºC to 26ºC)
- Humidity (%): 50% ± 20%
- Air changes (per hr): ten or more air changes per hour with 100% fresh air
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark cycle

IN-LIFE DATES: From: To:

Thirty six male and 36 female Hartley-derived albino guinea pigs were received on 02 Jul 2012 (Shipment 1) from Charles River Laboratories, Saint Constant Quebec, Canada. Thirty six male and 36 female Hartley-derived albino guinea pigs were received on 17 Jul 2012 (Shipment 2) from Charles River Laboratories, Raleigh, NC. Six male and 6 female Hartley-derived albino guinea pigs were received on 13 Sep 2012 (Shipment 3) from Charles River Laboratories, St. Constant, Quebec, Canada. The animals were examined and weighed on the day following receipt.

The male range-finding animals were approximately 5 weeks of age on the day prior to dosing with body weights of 392 to 417 grams. The female range-finding animals were approximately 6 weeks of age on the day prior to dosing with body weights of 359 to 399 grams. The male second range-finding animals were approximately 9 weeks of age on the day prior to dosing with body weights of 659 to 698 grams. The female second range-finding animals were approximately 10 weeks of age on the day prior to dosing with body weights of 501 to 504 grams.
The male main phase animals were approximately 6 weeks of age on the day prior to Induction 1 dosing with body weights ranging from 319 to 505 grams. The female main phase animals were approximately 7 weeks of age on the day prior to Induction 1 dosing with body weights ranging from 371 to 462 grams.
The male second rechallenge animals were approximately 5 weeks of age on the day prior to dosing with body weights ranging from 334 to 365 grams. The female second rechallenge animals were approximately 5 weeks of age on the day prior to dosing with body weights ranging from 311 to 333 grams.

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
other: White mineral oil USP
Concentration / amount:
Induction: 100 %
Challenge / Rechallenge / Second Rechallenge: 50 %
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
other: White mineral oil USP
Concentration / amount:
Induction: 100 %
Challenge / Rechallenge / Second Rechallenge: 50 %
No. of animals per dose:
10 (test group), 5 (challenge control), 5 (rechallenge control), 5 (second rechallenge), 5 (HCA Test), 5 (HCA control)
Details on study design:
RANGE FINDING TESTS:
Prior to initial of the main sensitization study, a topical range-finding study was conducted in guinea pigs to aid in the selection of dosage levels.
An initial range-finding study was iconducted, using animals from Shipment 1. These animals were euthanized and discarded. During this time, the feed given to Shipment 1 animals was found to have Vitamin D levels that were more than 100-fold greater than the manufacturer’s specified limits and this lot of feed was recalled by the manufacturer. Therefore, all animals from the first shipment were euthanized following discussion with the Sponsor, based on the concern that the excessive Vitamin D level might affect the overall outcome of the study. The data from the initial range-finding phase were maintained in the study records and will not be reported. Therefore, all report references regarding range-finding are associated with the second shipment of animals. A second shipment of animals was received to facilitate study conduct. The range-finding study was conducted with test substance administration. A second topical range-finding study to determine appropriate levels for challenge was conducted.
The dermal route of exposure was selected because this is the intended route of human exposure.
Four graded levels are utilized for this procedure. Optimally, the range-finding study should produce no systemic toxicity and a spectrum of dermal responses that include Grades 0, ±, 1, and 2 unless the test substance is not dermally irritating at 100%.

On the day prior to dosing, the guinea pigs selected for the topical range-finding study were weighed and the hair removed from the right and left side of the animals with a small animal clipper. Care was taken to avoid abrading the skin during the clipping procedures. On Day 0, 4 concentrations of the test substance were prepared and a 0.3 mL dose of each concentration was applied to the clipped area of each topical range-finding animal. The
chambers were applied to the clipped surface as quickly as possible. The trunk of the animal was wrapped with elastic wrap which was secured with adhesive tape to prevent removal of the chambers and the animal was returned to its cage.
Approximately 6 hours after chamber application, the binding materials were removed. The test sites were then wiped 2 times with gauze moistened in mineral oil, followed by dry gauze, and then wiped with gauze moistened in deionized water, followed by dry gauze, to remove test substance residue and the animals were returned to their cages.
The animals were observed for general health/mortality and moribundity twice daily, once in the morning and afternoon, throughout the study.
The test sites of each topical range-finding animal were graded for irritation at approximately 24 and 48 hours after chamber application using the Macroscopic Dermal Grading System.
Each topical range-finding animal was weighed on the day prior to dosing (Day -1).
Following the 48-hour scoring interval, all range-finding animals were euthanized by carbon dioxide inhalation and discarded.

Results of the range-Finding Phase: Exposure of test material at concentrations of 25 %, 50 %, 75 % and 100 % resulted in dermal scores of 0. Therefore, induction was determined to be acceptable at 100 % (as received).
A second range-finding study conducted, based on the scores noted during the induction phase at concentrations of 30%, 40%, 50%, and 75% to determine an appropriate challenge level resulted in dermal scores of ± or 0. Therefore, challenge was determined to be acceptable at 50% (w/w) in mineral oil, based on the results of the 2 range-finding studies and discussion with Sponsor.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Site: left site of the test animals
- Frequency of applications: 3 (Day 0, Day 7 and Day 14)
- Duration: 6 hours
- Concentrations: 100 %
On the day prior to dosing, the guinea pigs selected for the main study had the hair removed with a small animal clipper. Care was taken to avoid abrading the skin during the clipping procedures.
On the following day, a 0.3 mL dose of the appropriate test or positive control substance was placed on a 25 mm Hilltop chamber backed by adhesive tape (occlusive patch). The chambers were then applied to the clipped surface of the appropriate animals as quickly as possible. Following chamber application, the trunk of the animal was wrapped with elastic wrap which was secured with adhesive tape to prevent removal of the chamber and the animal was returned to its cage.
Approximately 6 hours after chamber application, the binding materials were removed. The test sites were then wiped 2 times with gauze moistened in mineral oil, followed by dry gauze, followed by gauze moistened in deionized water, followed by dry gauze, to remove test substance residue, and the animals were returned to their cages.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: day 29
- Exposure period: 6 hours
- Site: right site of the test animals
- Concentrations: 50 %
- Evaluation (hr after challenge):

C. RECHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of rechallenge: day 37
- Exposure period: 6 hours
- Site: right site of the test animals
- Concentrations: 50 %

D. SECOND RECHALLENGE EXPOSURE:
- No. of exposures: 1
- Day(s) of rechallenge: day 50
- Exposure period: 6 hours
- Site: right site of the test animals
- Concentrations: 50 %´
Positive control substance(s):
yes
Remarks:
alpha-Hexylcinnamaldehyde (1.0 %, 2.5 % and 5.0 % in Acetone or Ethanol (for 5 %))

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
other: Induction 1
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
3 of 20 animals showed a +/- dermal reacion 24 hours after the first induction exposure.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 1. . Hours after challenge: 24.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 3 of 20 animals showed a +/- dermal reacion 24 hours after the first induction exposure..
Reading:
other: Induction 1
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
3 of 20 animals showed a +/- dermal reacion 48 hours after the second induction exposure.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 1. . Hours after challenge: 48.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 3 of 20 animals showed a +/- dermal reacion 48 hours after the second induction exposure..
Reading:
other: Induction 2
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
12 of 20 animals showed a +/- dermal reaction, 5 of 20 animals showed a grade 1 erythema dermal reacion 24 hours after the second induction exposure. Moreover 2 animals showed a grade 2 edema and a grade one erythema.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 2. . Hours after challenge: 24.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 12 of 20 animals showed a +/- dermal reaction, 5 of 20 animals showed a grade 1 erythema dermal reacion 24 hours after the second induction exposure. Moreover 2 animals showed a grade 2 edema and a grade one erythema..
Reading:
other: Induction 2
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
11 of 20 animals showed a +/- dermal reaction, 5 of 20 animals showed a grade 1 erythema dermal reacion 48 hours after the second induction exposure. Moreover 2 animals showed a grade 1 desquamation.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 2. . Hours after challenge: 48.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 11 of 20 animals showed a +/- dermal reaction, 5 of 20 animals showed a grade 1 erythema dermal reacion 48 hours after the second induction exposure. Moreover 2 animals showed a grade 1 desquamation..
Reading:
other: Induction 3
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
9 of 20 animals showed a +/-dermal reaction, 7 showed a grade 1 erythema dermal reacion & 1 animals showed a grade 2 erythema dermal reaction 24 hours after the third induction exposure. Moreover 2 animals showed a grade 2 edema and a grade one erythema.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 3. . Hours after challenge: 24.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 9 of 20 animals showed a +/-dermal reaction, 7 showed a grade 1 erythema dermal reacion & 1 animals showed a grade 2 erythema dermal reaction 24 hours after the third induction exposure. Moreover 2 animals showed a grade 2 edema and a grade one erythema..
Reading:
other: Induction 3
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
10 of 20 animals showed a +/-dermal reaction, 4 showed a grade 1 erythema dermal reacion & 1 animals showed a grade 2 desquamation 48 hours after the third induction exposure.
Remarks on result:
other: see Remark
Remarks:
Reading: other: Induction 3. . Hours after challenge: 48.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 10 of 20 animals showed a +/-dermal reaction, 4 showed a grade 1 erythema dermal reacion & 1 animals showed a grade 2 desquamation 48 hours after the third induction exposure..
Reading:
other: first challenge
Hours after challenge:
24
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
6 of 20 animals, respectively, showed a +/- dermal reaction
Remarks on result:
other: Reading:
Reading:
other: first challenge
Hours after challenge:
48
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
5 of 20 animals showed a +/- dermal reaction
Remarks on result:
other: Reading:
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
4 of 20 animals showed a +/- dermal reaction
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 50 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 4 of 20 animals showed a +/- dermal reaction.
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
7 of 20 animals showed a +/- dermal reaction
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 50 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: 7 of 20 animals showed a +/- dermal reaction.
Reading:
other: second rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
8 of 20 animals showed a +/- dermal reaction
Remarks on result:
other: Reading:
Reading:
other: second rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
9 of 20 animals showed a +/- dermal reaction
Remarks on result:
other: Reading:

Any other information on results incl. tables

No mortality occured during the study.

Induction Phase

During the induction, dermal scores of 0, ± (slight patchy erythema), 1 (slight, confluent or moderate patchy erythema), and 2 (moderate, confluent erythema) were noted for the test animals. Additional observations included edema scores of 1, and desquamation.

Challenge Phase

Following challenge with 50% w/w test material in mineral oil, dermal scores of ± were noted in 6/20 test animals at the 24-hour scoring interval. At the 48-hour scoring interval, dermal scores of ± were noted in 5/20 test animals. Dermal reactions in the remaining test and challenge control animals were limited to scores of 0. Group mean dermal scores were noted to be slightly

higher in the test animals as compared to the challenge control animals. Based on the response noted in the challenge control animals, a rechallenge was conducted to attempt to elicit additional responses.

Following challenge with 2.5% w/v HCA in acetone, dermal scores of 1 or 2 were noted in all HCA test animals at the 24-hour and 48-hour scoring intervals. Dermal reactions in the HCA control animals were limited to scores of 0 or ±. Group mean dermal scores were higher in the HCA test animals compared to the HCA control animals.

Following challenge with 1.0% w/v HCA in acetone, dermal scores of 1 were noted in 8/10 HCA test animals at the 24-hour scoring interval, and in 4/10 test animals at the 48-hour scoring interval. Dermal reactions in the HCA control animals were limited to scores of 0 or ±. Group mean dermal scores were higher in the HCA test animals compared to the HCA control animals.

Rechallenge and Second Rechallenge Phases

Following rechallenge with 50% w/w test material in mineral oil, dermal scores of ± were noted in 9/20 test animals at the 24- and 48-hour scoring intervals. Dermal reactions in the remaining test and rechallenge control animals were limited to scores of 0. Group mean dermal scores were noted to be slightly higher in the test animals as compared to the rechallenge control animals. Therefore, a second rechallenge was conducted in an attempt to elicit an additional response in the test animals. Following second rechallenge with 50% w/w Test material in mineral oil, dermal scores of ± were noted in 9/20 test animals at the 24- and 48-hour scoring intervals. Dermal reactions in the remaining test and rechallenge control animals were limited to scores of 0. Group mean dermal scores were noted to be slightly higher in the test animals as compared to the second rechallenge control animals.

Body Weights

No test material-related effects on body weight were observed in the test animals during the study. Weight gain in the animals throughout the study interval was indicative of good health in the test and control animals.

Based on the nature of the material and the increased irritation as the induction phase progressed, the rechallenge and second rechallenge phases were conducted in an attempt to elicit a sensitization response from the test animals, in the event the material could be a weak sensitizer. Following completion of the study, the irritation response noted during the induction phase was considered a cumulative effect resulting from the same test site being dosed throughout induction and was, therefore, not considered to be an indication of sensitization.

TABLE 3
A DERMAL SENSITIZATION STUDY IN GUINEA PIGS
INDIVIDUAL INDUCTION DATA
Test material
    INDUCTION1 DERMAL SCORES INDUCTION2 DERMAL SCORES INDUCTION3 DERMAL SCORES
  100%a 100%a 100%a
GROUP ANIMAL NO./SEX 24HOURS 48HOURS 24HOURS 48HOURS 24HOURS 48HOURS
TEST G5961/M 0 0 ± ± ± ±
G5962/M 0 0 0 0 ± 0
G5963/M 0 ± 1 1 ± ±
G5964/M 0 0 ± ± 0 0
G5965/M 0 0 0 0 0 0
G5966/M ± ± 1 ± 1 ±
G5967/M 0 0 ± ± 1 1
G5968/M 0 0 1 1 1 1
G5969/M 0 0 ± ± ± ±
G5970/M ± ± 2ED-1 1DES 2 1DES
G5997/F 0 0 ± 1 ± 0
G5998/F 0 0 ± ± ± ±
G5999/F ± 0 ± ± ± ±
G6000/F 0 0 ± ± 0 0
G6001/F 0 0 ± ± 1 ±
G6002/F 0 0 1 1 1 1
G6003/F 0 0 1 1 1 ±
G6004/F 0 0 ± ± 1 1
G6005/F 0 0 ± ± ± ±
G6006/F 0 0 ± 0 ± ±
(HCA)
GROUP ANIMAL NO./SEX INDUCTION1 DERMAL SCORES INDUCTION2 DERMAL SCORES INDUCTION3 DERMAL SCORES
5.0%a 5.0%a 5.0%a
24HOURS 48HOURS 24HOURS 48HOURS 24HOURS 48HOURS
HCA TEST G5981/M 0 ± M3ED-1, ES-4 M3ED-1, ES-4 1 1ED-1, BLA-1
G5982/M 1 2ED-1, SL-2 M3ED-2, ES-4 M3ED-2, ES-4 2ED-1 2ED-1
G5983/M 1 2ED-1, SL-2 M3ED-1, BLA-3 M3ED-2, ES-4 2ED-1 2ED-1
G5984/M ± 2ED-1, SL-4 M3ED-1, BLA-4 M3ED-1, ES-4 2ED-1, BLA-1 2ED-1, ES-1
G5985/M 1 2ED-1, SL-3 M3ED-1, BLA-4 M3ED-1, BLA-4 2ED-1, SL-3 2ED-1, SL-3, BLA-1
G6017/F 1 2ED-1 M3ED-2, BLA-4 M3ED-2, ES-4 2ED-1, SL-2, BLA-1 2ED-1, SL-2, ES-1
G6018/F ± 2ED-1, SL-4 M3ED-1, BLA-3 M3ED-1, BLA-3 2ED-1, SL-2 2ED-1, SL-2
G6019/F 1 1 M3ED-1, BLA-4 M3ED-2, ES-4 2ED-1 2ED-1
G6020/F ± 1 M3ED-1, SL-2, BLA-2 M3ED-1, BLA-2 2ED-1, BLA-1 1ED-1, ES-1
G6021/F ± 2ED-1, SL-4 M3ED-1, BLA-4 M3ED-2, ES-4 2ED-1, SL-2 2ED-1, BLA-1
aAS RECEIVED.
aTHE VEHICLE USED WAS ETHANOL.

TABLE 4
A DERMAL SENSITIZATION STUDY IN GUINEA PIGS
INDIVIDUAL CHALLENGE DATA
Test material
  DERMAL SCORES
  50%a  
GROUP ANIMAL NO./SEX 24HOURS 48HOURS
TEST G5961/M 0 0
G5962/M 0 0
G5963/M ± ±
G5964/M 0 0
G5965/M 0 0
G5966/M ± ±
G5967/M 0 0
G5968/M 0 0
G5969/M 0 0
G5970/M ± ±
G5997/F 0
G5998/F 0 0
G5999/F 0 0
G6000/F 0 0
G6001/F 0 0
G6002/F ± 0
G6003/F ± ±
G6004/F ± ±
G6005/F 0 0
G6006/F 0 0
MEAN 0.15 0.13
CHALLENGE CONTROL G5971/M 0 0
G5972/M 0 0
G5973/M 0IT 0
G5974/M 0IT 0
G5975/M 0 0
G6007/F 0IT 0
G6008/F 0 0
G6009/F 0 0
G6010/F 0 0
G6011/F 0 0
MEAN 0.0 0.0
FOR PURPOSES OF CALCULATION, ±= 0.5.
aTHE VEHICLE USED WAS MINERAL OIL.

TABLE 4 (continued)
A DERMAL SENSITIZATION STUDY IN GUINEA PIGS
INDIVIDUAL CHALLENGE DATA
(HCA)
GROUP ANIMAL NO./SEX DERMAL SCORES
2.5%a 1.0a
24HOURS 48HOURS 24HOURS 48HOURS
HCA TEST G5981/M 2ED-1 2 1 1
G5982/M 2ED-1 2 1 1
G5983/M 1 1 1 ±
G5984/M 1IT 1 1 ±
G5985/M 1 1 1 1
G6017/F 1 1 1 ±
G6018/F 1 1 1 ±
G6019/F 1 1 1 1
G6020/F 1 1 ± ±
G6021/F 1 1 ± ±
MEAN 1.2 1.2 0.9 0.7
HCA CHALLENGE CONTROL G5986/M ± ± ± 0
G5987/M 0 0 0 0
G5988/M 0 0 0 0
G5989/M 0 0 0 0
G5990/M 0 0 0 0
G6022/F 0 0 0 0
G6023/F 0 0 0 0
G6024/F 0 0 0 0
G6025/F 0 0 0 0
G6026/F 0 0 0 0
MEAN 0.05 0.05 0.05 0.0
FOR PURPOSES OF CALCULATION, ±= 0.5.
aTHE VEHICLE USED WAS ACETONE.

TABLE 5
A DERMAL SENSITIZATION STUDY IN GUINEA PIGS
INDIVIDUAL RECHALLENGE DATA
Test material
GROUP ANIMAL NO./SEX DERMAL SCORES
50%a
24HOURS 48HOURS
TEST G5961/M 0 0
G5962/M 0 0
G5963/M ± ±
G5964/M 0 0
G5965/M 0 0
G5966/M 0 0
G5967/M ± ±
G5968/M ± ±
G5969/M 0IT
G5970/M ±IT
G5997/F ±IT ±IT
G5998/F 0b 0b
G5999/F 0 0
G6000/F 0 0
G6001/F ±IT
G6002/F 0IT 0IT
G6003/F ±IT
G6004/F 0IT 0IT
G6005/F 0 0
G6006/F 0IT 0
MEAN 0.23 0.23
RECHALLENGE CONTROL G5976/M 0IT 0IT
G5977/M 0 0
G5978/M 0IT 0IT
G5979/M 0IT 0IT
G5980/M 0 0
G6012/F 0 0
G6013/F 0 0
G6014/F 0 0
G6015/F 0IT 0
G6016/F 0 0
MEAN 0.0 0.0
FOR PURPOSES OF CALCULATION, ± = 0.5.
aTHE VEHICLE USED WAS MINERAL OIL.
bPATCH FOUND OFF AT TIME OF REMOVAL.

TABLE 6
A DERMAL SENSITIZATION STUDY IN GUINEA PIGS
INDIVIDUAL SECOND RECHALLENGE DATA
Test material
GROUP ANIMAL NO./SEX DERMAL SCORES
50%a
24HOURS 48HOURS
SECOND RECHALLENGE CONTROL TEST G5961/M 0 0
G5962/M 0 0
G5963/M ± ±
G5964/M 0 0
G5965/M 0 0
G5966/M ± ±
G5967/M 0 0
G5968/M ± ±
G5969/M ± ±
G5970/M ± ±
G5997/F ±
G5998/F 0 0
G5999/F 0 0
G6000/F 0 0
G6001/F ± ±
G6002/F 0 0
G6003/F ± ±
G6004/F ± ±
G6005/F 0 0
G6006/F 0 0
MEAN 0.23 0.23
SECOND RECHALLENGE CONTROL G6204/M 0 0
G6205/M 0 0
G6206/M 0 0
G6207/M 0 0
G6208/M 0 0
G6210/F 0 0
G6211/F 0 0
G6212/F 0 0
G6213/F 0 0
G6214/F 0 0
MEAN 0.0 0.0
FOR PURPOSES OF CALCULATION, ±= 0.5.
aTHE VEHICLE USED WAS MINERAL OIL.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: other: EU-GHS
Conclusions:
Based on the results of this study, the test material is not considered to be a contact sensitiser in guinea pigs, as the criterion for sensitisation (dermal scores ≥ 1 in at least 15% of the test animals) was not met. The results of the HCA positive control study demonstrated that a valid test was performed and indicated that the test design would detect potential contact sensitisers.
Executive summary:

The dermal sensitisation potential of the test material was evaluated in Hartley-derived albino guinea pigs (Smedley, 2012). Ten male and 10 female guinea pigs were topically treated with 100% (as received) the test material once per week, for 3 consecutive weeks. Following a 2-week rest period, a challenge was performed whereby the 20 test and 10 previously untreated (naïve) challenge control guinea pigs were topically treated with 50% w/w test material in mineral oil. Challenge responses in the test animals were slightly higher than those of the challenge control animals. Following a 1-week rest period, a rechallenge was performed in which the 20 test and 10 previously untreated (naïve) rechallenge control guinea pigs were topically treated with 50% w/w test material in mineral oil. Rechallenge responses in the test animals were slightly higher than those of the control animals. Following a 2-week rest period, a second rechallenge was performed in which the 20 test and 10 previously untreated (naïve) second rechallenge control guinea pigs were topically treated with 50% w/w test material in mineral oil. Second rechallenge responses in the test animals were slightly higher than those of the control animals. An α-Hexylcinnamaldehyde (HCA) positive control group consisting of 10 HCA test and 10 HCA control guinea pigs was included in this study. The animals were treated as above with the HCA test animals receiving 5% w/v HCA in ethanol for induction and 2.5% and 1.0% w/v HCA in acetone for challenge.

Following challenge with 50% w/w test material in mineral oil, dermal scores of ± were noted in 6/20 test animals at the 24-hour scoring interval. At the 48-hour scoring interval, dermal scores of ± were noted in 5/20 test animals. Dermal reactions in the remaining test and challenge control animals were limited to scores of 0. Group mean dermal scores were noted to be slightly higher in the test animals as compared with the challenge control animals. Based on the response noted in the challenge control animals, a rechallenge was conducted to attempt to elicit additional responses.

Following rechallenge with 50% w/w test material in mineral oil, dermal scores of ± were noted in 9/20 test animals at the 24- and 48-hour scoring intervals. Dermal reactions in the remaining test and rechallenge control animals were limited to scores of 0. Group mean dermal scores were slightly higher in the test animals as compared to the rechallenge control animals. Therefore, a second rechallenge was conducted in an attempt to elicit an additional response in the test animals.

Following second rechallenge with 50% w/w test material in mineral oil, dermal scores of ± were noted in 9/20 test animals at the 24- and 48-hour scoring intervals. Dermal reactions in the emaining test and rechallenge control animals were limited to scores of 0. Group mean dermal scores were noted to be slightly higher in the test animals as compared with the second rechallenge control animals.

Following challenge with 2.5% w/v alpha-hexylcinnamaldehyde (HCA) in acetone, dermal scores of 1 or 2 were noted in all HCA test animals at the 24-hour and 48-hour scoring intervals. Dermal reactions in the HCA control animals were limited to scores of 0 or ±. Group mean dermal scores were higher in the HCA test animals compared to the HCA control animals. Following challenge with 1.0% w/v HCA in acetone, dermal scores of 1 were noted in 8/10 HCA test animals at the 24-hour scoring interval, and in 4/10 test animals at the 48-hour scoring interval. Dermal reactions in the HCA control animals were limited to scores of 0 or ±. Group mean dermal scores were higher in the HCA test animals compared to the HCA control animals.

Based on the results of this study, the test material is not considered to be a contact sensitizer in guinea pigs, as the criterion for sensitization (dermal scores ≥ 1 in at least 15% of the test animals) was not met. The results of the HCA positive control study demonstrated that a valid test was performed and indicated that the test design would detect potential contact sensitizers.