Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
EPA OPP 81-6 (Skin Sensitisation)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
other: EPA Health Effects Testing Guidelines - Subpart E - Specific Organ/Tissue Toxicity 40 CFR Part 798
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
other: MAFF Japan, 59 NohSan No. 4200
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
GLP compliance:
yes
Type of study:
Buehler test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Purity: 99.9%

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Not reported
- Weight at study initiation: 482-600 g
- Housing: Stainless steel with elevated wire mesh flooring, 2-3 guinea pigs/cage
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.4-22.5°C
- Humidity (%): 48-70%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12-hour light/12-hour dark

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5 mL
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.5 mL
No. of animals per dose:
20 test animals
10 vehicle control animals
5 positive control animal
Details on study design:
RANGE FINDING TESTS: Prior to the initiation of the study, the irritation potential was determined. Four unexposed animals were exposed to two concentrations of the test material by the patching technique. In this test, both sides of the animals were closely clipped and exposed to the test substance as supplied and a 50% w/v concentration in polyethylene glycol. The test site was wiped with deionized water following the removal of the patch, examined, and scored for irritation according to the Scale for Evaluation of Dermal Irritation at 24 and 43 hours from the initial patch application. Very faint redness was observed on 1 or 4 animals at the 100% site and no dermal irritation was observed at the 50% sites. The induction and challenge applications were performed using 0.5 mL of the test material as supplied.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Test groups: 20 guinea pigs
- Control group: Vehicle control group was given 0.5 mL saline; Positive control group was given 0.5 mL of 0.1% 1-chloro-2,4-dinitrobenzene (DNCB) w/v in 50% ethanol:0.9% saline
- Site: Shaved left flank (approximately 1.5x1.5 inches)
- Frequency of applications: Once a week
- Duration: 3 weeks
- Concentrations: 0.5 mL of the test material as supplied


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Approximately 18 days after the third induction application
- Exposure period: 6 hours
- Test groups: 20 guinea pigs
- Control group: The vehicle control group was challenged with saline on the clipped left flank. The test material (100%), as supplied, was placed on the naive clipped right flank. A challenge application of 0.07% in DNCB in acetone was tested for the positive control. A group of 5 naive animals was also treated.
- Site: Shaved right flank
- Concentrations: 0.5 mL of test material as supplied
- Evaluation (hr after challenge): approximately 24 and 48 hours after challenge application

OTHER: Upon removal of the patches in the induction and challenge phases, the test sites were wiped with deionized water and marked with a colour marker to indicate the challenge application sites. All test sites were scored on a scale of 0 to 3.
Challenge controls:
A group of 5 naive animals was also treated with the positive control substance.
Positive control substance(s):
yes
Remarks:
0.1% 1-chloro-2,4-dinitrobenzene (DNCB)

Study design: in vivo (LLNA)

Statistics:
Individual body weight percentage gain was statistically evaluated by Analysis of Variance (ANOVA), with the Neuman Keuls test applied in the event of a significant finding for the data.

Results and discussion

Positive control results:
There were no statistically significant differences identified between the individual body weight percentage gains of the positive control group and the positive control naive group. However, there was a significant difference between the individual body weight percentage gains of the positive control group, the test article group, and the vehicle control group. No to moderate redness was observed during the induction phase. After challenge, the incidence of sensitisaiton was 5/5 and the severity was 2.0 at 24 and 48 hours. The positive control, when compared to the dermal reaction elicited on the naive animals at challenge, is a dermal sensitiser in this study.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
other: vehicle control
Dose level:
vehicle control
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group:
Reading:
2nd reading
Hours after challenge:
48
Group:
other: vehicle control
Dose level:
vehicle control
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group:
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1%
No. with + reactions:
5
Total no. in group:
5
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.1%. No with. + reactions: 5.0. Total no. in groups: 5.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
0.1%
No. with + reactions:
5
Total no. in group:
5
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 0.1%. No with. + reactions: 5.0. Total no. in groups: 5.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability). Under the study conditions utilized, repeated administration of the test substance did not produce delayed contact hypersensitivity in guinea pigs.
Executive summary:

The potential of the test substance to produce delayed contact hypersensitivity in guinea pigs was assessed by the Modified Buehler Method. Twenty test substance animals were induced and challenged by occluded application of the test material to clipped intact guinea pig skin. The same procedures were carried out on contemporaneous control groups except that the test substance was replaced by vehicle (saline) or positive control (1-chloro-2,4-dinitrobenzene). During the induction phase, no redness was observed on the test substance animals. Twenty-four or 48 hours after the challenge application, no dermal irritation was observed at either the vehicle or test article sites. The positive control animals exhibited no to moderate redness during the induction phase. Twenty-four and 48 hours after the challenge application, faint to severe redness with or without swelling and exfoliation (dry, flaky skin) was observed. Very faint redness was exhibited by 1 of 5 animals in the naïve positive control group 24 hours after the challenge application. It was concluded, therefore, that under the study conditions utilized, repeated administration of the test substance did not produce delayed contact hypersensitivity in guinea pigs. It was also concluded that DNCB, when induced as a 0.1% w/v concentration in a 50% ethanol:0.9% saline solution and challenged as a 0.07% w/v concentration in acetone produced delayed contact hypersensitivity in albino guinea pigs. On the basis of the nature of effects observed in this study and according to the guide of the labelling of dangerous substances published in the Official Journal of the European Communities, the test substance is not a skin sensitizer.