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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
other: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
from March 10 to May 26, 1994
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
EU method B.6 (Skin sensitisation)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
A LLNA study has not been conducted because adequate data from guinea pig Maximisation test study are already available.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Pirbright-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: CIBA-GEIGY Limited Animal Production 4332 Stein / Switzerland
- Weight at study initiation: between 358g to 413g
- Housing: individually in Macrolon cages (Type 3)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): from 19 to 25°C
- Humidity (%): 30 to 70%
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
other: Physiological saline; Bacto adjuvant; Vaseline
Concentration / amount:
5% in induction phaseby intradermal injection
50% in induction phaseby epidermal application
50% in challenge phase
10% in rechallenge phase
Challenge
Route:
epicutaneous, occlusive
Vehicle:
other: Physiological saline; Bacto adjuvant; Vaseline
Concentration / amount:
5% in induction phaseby intradermal injection
50% in induction phaseby epidermal application
50% in challenge phase
10% in rechallenge phase
No. of animals per dose:
- for challenge, 5 males and 5 females per dose
- for rechallenge, 5 males and 5 females per dose
Details on study design:
RANGE FINDING TESTS:
A. INDUCTION EXPOSURE INTRADERMAL
- Concentrations: 5 % in physiological saline (w/v)

B. INDUCTION EXPOSURE EPIDERMAL
- Concentrations: 5, 10, 20, 30, and 50% in physiological saline

MAIN STUDY
A. INDUCTION EXPOSURE INTRADERMAL
- No. of exposures: 3 pairs of intradermal injections
- Exposure period: from day 0 to day 8
- Test groups: 5 males and 5 females
- Control group: 5 males
- Site: left and right side of shaved neck
- Concentrations: 1 pair of injection of adjuvant/saline mixture 1:1 (v/v); 1 pair of injection of 5% substance in physiological saline (w/v); 1 pair of injection of 5% substance in the adjuvant/saline mixture (w/v)

MAIN STUDY
B. INDUCTION EXPOSURE EPIDERMAL
- Pretreatment: 10% sodium-laurylsulfate (open application) 24 hours
- Test groups: 5 males and 5 females
- Control group: 5 males
- Exposure period: 48 hours
- Site: neck
- Duration: from day 8 to day 22
- Concentrations: 50% of substance n physiological saline

A. CHALLENGE EXPOSURE
- No. of exposures: 1 on each flank (1 test substance and 1 vehicle only)
- Day(s) of challenge: from day 22 to day 25
- Exposure period: 24 hours
- Test groups: 5 males and 5 females
- Control group: 5 males
- Site: flanks
- Concentrations: 50% in physiological saline
- Evaluation (hr after challenge): 24 and 48 hours after removing the dressing

B. RECHALLENGE EXPOSURE
- No. of exposures: 1 on each flank (1 test substance and 1 vehicle only)
- Day(s) of challenge: from day 28 to day 30
- Exposure period: 24 hours
- Test groups: 5 males and 5 females
- Control group: 5 females
- Site: flanks
- Concentrations: 10% in physiological saline
- Evaluation (hr after challenge): 24 and 48 hours after removing the dressing
Challenge controls:
5 males for challenge
5 females for rechallenge
Positive control substance(s):
yes
Remarks:
2-Mercaptobenzothiazole

Results and discussion

Positive control results:
Test and results fullfill the requirements for reliability check of the OECD Guideline 406 (page 2, paragraph 10 and 11).

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
50%
No. with + reactions:
8
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50%. No with. + reactions: 8.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
other: control group
Dose level:
50%
No. with + reactions:
2
Total no. in group:
5
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: control group. Dose level: 50%. No with. + reactions: 2.0. Total no. in groups: 5.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
50%
No. with + reactions:
10
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50%. No with. + reactions: 10.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
other: control group
Dose level:
50%
No. with + reactions:
2
Total no. in group:
5
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: control group. Dose level: 50%. No with. + reactions: 2.0. Total no. in groups: 5.0.
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
10%
No. with + reactions:
5
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 10%. No with. + reactions: 5.0. Total no. in groups: 10.0.
Reading:
rechallenge
Hours after challenge:
24
Group:
other: control group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: other: control group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 5.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
10%
No. with + reactions:
7
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 10%. No with. + reactions: 7.0. Total no. in groups: 10.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
other: control group
Dose level:
10%
No. with + reactions:
0
Total no. in group:
5
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: other: control group. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Applicant's summary and conclusion

Interpretation of results:
other: Category 1B (indication of skin sensitising potential) based on CLP criteria
Conclusions:
Skin sensitising
Executive summary:

Method

The study has been performed according to OECD guideline 406 and on Annex V, Part B of Council Directive 67/548/EEC.

The test has been performed in essence according to the original protocol of Magnusson and Kligman, on 5 male and 5 female guinea pigs in the test group and 5 male guinea pigs in the control group.

The animals were housed individually in Macrolon cages (Type 3), identified by individual ear tags, kept at a constant room temperature and a 12 hours light cycle day.

Test animals were initially exposed to the test substance by intradermal injection and epidermal application during a pretest phase. The test substance was selected at 5 % in physiological saline (w/v) for intradermal induction; after 7 days 5, 10, 20, 30 and 50 % of test substance in physiological saline were selected for an epidermal application. 50 % was the highest possible concentration of the test artcile in physiological saline. The tested concentrations did not induce erythema reactions. During the test procedure at day 0 the induction phase was performed with three pairs of intradermal injections (0.1 ml per injection) made simultaneously into the left and right side of the shaved neck of the test and control group animals. The injections of the test animals consisted of: - adjuvant/saline mixture 1:1 (v/v) - 5 % test article in physiological saline (w/v) - 5 % test article in the adjuvant/saline mixture (w/v).
The injections of the control group consisted of: - adjuvant/saline mixture 1:1 (v/v) - adjuvant/saline mixture 1:1 (v/v) - physiological saline (w/v)
At day 7 the application site of all animals was pretreated with 10 % sodium-laurylsulfate (open application) 24 hours prior to the epidermal induction application. At day 8 the substance at 50 % was incorporated in physiological saline and applied on a filterpaper patch to the neck of the animals (patch 2x4 cm; approx. 0.4 g per patch; occluded administration for 48 hours). The control group was treated with the physiological saline only. Following a resting period of 14 days (induction period), during which an immune response may develop, the animals were exposed to a challenge dose.

The test and control group animals were tested on one flank with substance at 50 % in physiological saline and on the other flank with the vehicle only (patch 2x2 cm; approx. 0.2 g per patch; occluded administration for 24 hours). At day 28 after that the first challenge application caused reactions in 40 % of the animals of the control group, a second challenge, using a lower test article concentration and a new control group, was performed. The test and control group animals were tested on one flank with substance at 10 % in physiological saline and on the other flank with the vehicle only (patch 2x2 cm; approx. 0.2 g per patch; occluded administration for 24 hours).

Observations

After the first challenge application 80 % and 100 % of the animals of the test group and 40 % of the animals of the control showed skin reactions. After the second challenge application, using a lower test article concentration, 50 % and 70 % of the animals of the test group at 24 and 48 hours respectively were sensitised, and none of the animals of the new control group showed skin reactions after removing the dressings.

Conclusions

Skin sensitising.