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Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1985-02-01 to 1985-08-01
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable without restriction because it was conducted according to or similar to OECD Guideline 406 without exceptions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Principles of method if other than guideline:
Method: other
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
The first-choice method according to REACH Annex VII §8.3, the Murine Local Lymph Node Assay, is known to give false positive results with hydrocarbon substances.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: Oily liquid
Details on test material:
Test substance: API 83-12 (CAS No. 64742-53-6)
- Name of test material (as cited in study report): API 83-12


- Physical state: clear, colorless liquid
- Viscosity, SSU:
53.5 at 100°F
33.3 at 210°F
- API Gravity: 26.2
- Flash Point: 255 °F
- Distillation range (°F) ASTM D86 Equiv: 533-713 (10-95%)
Initial Boiling Point (°F): 464
Final Boiling Point (°F): 796
- Pour Point (°F): 60
- Aniline Point (°F): 148.3
- Colour ASTM: 0.5

- Composition of test material ASTM D-2007, Wt. %:
Saturates: 61.6
Aromatics 36.1
Polar compounds: 2.3

Sulfur, Wt%: 0.019

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Hazleton Dutchland, Inc.
- Age at study initiation: young adult (5 to 6 weeks)
- Weight at study initiation: 422 to 593 grams
- Housing: individually house in cages
- Diet (e.g. ad libitum): Purina Certified Guinea Pig Chow #5026 provided ad libitum
- Water (e.g. ad libitum): water provided ad libitum
- Acclimation period: 14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 to 24°C
- Humidity (%): 37 to 58%
- Photoperiod (hrs dark / hrs light): 12 hours light/12 hours dark


IN-LIFE DATES: From: 1984-02-01 To: 1985-02-28

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: Paraffin oil
Concentration / amount:
Sensitising phase: 0.4 mL 50% v/v dilution in paraffin oil
Challenge phase: 0.4 mL 1% v/v dilution in paraffin oil
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: Paraffin oil
Concentration / amount:
Sensitising phase: 0.4 mL 50% v/v dilution in paraffin oil
Challenge phase: 0.4 mL 1% v/v dilution in paraffin oil
No. of animals per dose:
10 in treatment group, naive control group, and vehicle control group
20 in naive positive control group and positive control group
Details on study design:
1st application: Induction 50 % occlusive epicutaneous
2nd application: Challenge 1 % occlusive epicutaneous
RANGE FINDING TESTS: in a range-finding test an undiluted sample of test material was administered at concentration of 25, 50, and 75% v/v in paraffin oil

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: three
- Exposure period: six hours
- Test groups: one treatment control group
- Control group: positive and vehicle control groups
- Site: backs of animals
- Frequency of applications: once a week
- Duration: three weeks
- Concentrations: 50%


B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: one
- Exposure period: six hours
- Test groups: one treatment group
- Control group: naive and vehicle control group; naive positive and positive control group
- Site: backs of animals
- Concentrations: 0.1%
- Evaluation (hr after challenge): 24 hours


Challenge controls:
naive control group dosed with 0.4 mL of 0.1% v/v mixture of test material in paraffin wax
vehicle control group dosed with 0.4 mL of undiluted paraffin oil
positive control group and naive positive control groups were dosed with 0.4 mL of a 0.1% v/v suspension of 2,4 dinitrochlorobenzene in acetone
Positive control substance(s):
yes
Remarks:
2,4 dinitrochlorobenzene

Results and discussion

Positive control results:
In the positive control group, very slight to severe irritation was exhibited by all 20 animals. The reactions of 18 animals exceeded the highest reaction observed in the naive positive control animals.

In the naive positive control group three of the twenty animals exhibited very slight erythema reactions. The other 17 animals exhibited no reaction.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
other: average of two challenge readings
Hours after challenge:
48
Group:
test group
Dose level:
1% v/v
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
slight erythema reaction exhibited by one animal; not considered a significant sensitising response
Remarks on result:
other: see Remark
Remarks:
Reading: other: average of two challenge readings. Group: test group. Dose level: 1% v/v. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: slight erythema reaction exhibited by one animal; not considered a significant sensitising response.
Reading:
other: average of two challenge readings
Hours after challenge:
48
Group:
negative control
Dose level:
Undiluted Paraffin Oil
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
No reaction exhibited by any animal
Reading:
other: average of two challenge readings
Hours after challenge:
48
Group:
positive control
Dose level:
0.3% w/v
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
Very slight to severe irritation was exhibited by all 20 animals

Any other information on results incl. tables

The criteria used to evaluate the responses are described in the report  as follows:
Determination of sensitization was based upon reactions to the challenge
 dose. Grades of 1 or greater in the test animals indicate evidence of  sensitization, provided grades of less than 1 are seen in the naive  controls. If grades of 1 or greater are noted in the naive control  animals, then the reactions of test animals that exceed the most severe  naive control reaction are considered sensitization reactions.

One animal had a score of 0.5 after challenge with API 83-12. In
 contrast, all the positive control animals were sensitized by their treatment. The sample of API 83-12 was therefore non sensitizing.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The test material is classified as not sensitising
Executive summary:

In the induction phase of a skin sensitisation study, 0.4 mL of a 50% mixture of test material and paraffin oil was applied under an occlusive dressing to the shorn skin of 10 male and 10 female animals. Six hours after application, the dressings were removed and the skin wiped to remove residues of test material. The animals received one application each week for three weeks. The same application site was used each time. Two weeks following the third application, a challenge dose (0.4 ml of a 1% mixture in paraffin oil) was applied in the same manner as the sensitizing doses. A previously untreated site was used for the challenge application. The application sites for induction and challenge doses were read for erythema and oedema 24 and 48 hours after patch removal. To assist in the reading of the response to the final challenge dose the test site was depilated three hours prior to reading by using a commercially available depilatory cream. 2,4-dinitrochlorobenzene at 0.3% in 80% aqueous ethanol at was used as the positive control in the induction phase and 2,4-dinitrochlorobenzene in acetone was used as the positive control in the challenge phase. Vehicle control and naive control groups were included in this study and the procedure for these was the same as for the test groups.

In the challenge phase, one animal in the treatment group exhibited a very slight erythema reaction. No animals exhibited reaction in the naive or vehicle control group. In the positive control group, 20 animals exhibited a very slight to severe irritation reaction. The reactions of 18 animals exceeded the highest reaction observed in the naive positive control animals. In the naive positive control group, three animals exhibited very slight erythema reactions. Based on these results, the test material is not considered to be a skin sensitizer under the conditions of this study.

This study received a Klimisch score of 1 and is classified as reliable without restriction because it was conducted according to or similar to OECD Guideline 406.