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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 August 30 to September 30, 1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
read-across from supporting substance (structural analogue or surrogate)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report Date:
1993

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
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:
solid: particulate/powder

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
- Age at study initiation: no data
- Weight at study initiation: Males 367.6 g, Female to 376.3 g
- Housing:The animals were housed individually in Macrolon cages (Type 3), assigned to the different groups by means of random numbers generated by the random number generator
- Diet: ad libitum standard guinea pig pellets - NAFAG No. 845
- Water: fresh water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22 ± 3 °C
- Humidity (%): 30 to 70%
- Photoperiod (hrs dark / hrs light): 12 hours cycle dark/light

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
other: Injection: physiological saline, epidermal application: vaseline
Concentration / amount:
INDUCTION
FIRST
Test group:
- adjuvant/saline mixture 1:1 (v/v)
- 5 % of the test item in physiological saline (w/v)
- 5 % of the test item in the adjuvant/saline mixture (w/v)
Control group:
- adjuvant/saline mixture 1:1 (v/v)
- adjuvant/saline mixture 1:1 (v/v)
- physiological saline
SECOND
Test group:
- 50 % of the test item (0.4 g per patch) in vaseline
Control group:
- vaseline only

CHALLENGE
Test and control group:
- 50 % of the test item (0.2 g per patch) in vaseline
Control group:
- vaseline only
Challenge
Route:
epicutaneous, occlusive
Vehicle:
other: Injection: physiological saline, epidermal application: vaseline
Concentration / amount:
Test and control group:
- 50 % of the test item (0.2 g per patch) in vaseline
Control group:
- vaseline only
No. of animals per dose:
The test was performed on 10 male and 10 female guinea pigs in the test group and 5 males and 5 females in the control group.
Details on study design:
PRETEST:
Intradermal Induction
The concentration for the intradermal injections was selected on account of the solubility of the test article in standard vehicles and its local and systemic tolerability in a pretest.
The following concentration of test article has been used for intradermal injection:
5 % in physiological saline (w/v).
Since 5 % of the test item in physiological saline could be injected and was well tolerated, this concentration was used for the intradermal induction.
Epidermal Applications (induction and challenge)
The concentrations for the epidermal applications were selected on account of the primary irritation potential of the test article. The following concentrations of the test item have been examined on separate animals for the determination of the maximum subirritant concentration:
30 and 50 % in vaseline.
50 % in vaseline was the highest applicable concentration of the test article.
The tested concentrations did not induce erythema reactions.

MAIN STUDY
The induction was a two-stage operation. First, intradermal injections (into the neck region); second, closed patch exposure over the injection sites one week later.

A. INDUCTION EXPOSURE
FIRST INDUCTION
Three pairs of intradermal injections (0.1 ml per injection) were made simultaneously into the left and right side of the shaved neck of the test and control group animals.
- No. of exposures: Three pairs of intradermal injections
- Exposure period: first week
- Test groups: 10 males and 10 females
- Control group: 5 males and 5 females
- Site: shaved neck
- Concentrations:
Test group:
adjuvant/saline mixture 1:1 (v/v)
5 % of the test item in physiological saline (w/v)
5 % of the test item in the adjuvant/saline mixture (w/v)
Control group:
adjuvant/saline mixture 1:1 (v/v)
adjuvant/saline mixture 1:1 (v/v)
physiological saline

SECOND INDUCTION:
The application site of all animals was pretreated with 10% sodium-laurylsulfate (open application) 24 hours prior to the epidermal induction application.
In the test group the test item was incorporated in vaseline (w/w) 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).

- No. of exposures: one application
- Exposure period: second week
- Test groups:10 males and 10 females
- Control group:5 males and 5 females
- Site:shaved neck
- Concentrations:
Test group:
0.4 g of Acid Yellow 151 within vaseline
Control group:
vaseline only

B. CHALLENGE EXPOSURE
The test and control group animals were tested on one flank with the test item in vaseline (w/w) and on the other flank with the vehicle alone (patch 2x2 cm; approx. 0.2 g per patch; occluded administration for 24 hours).
- No. of exposures:
- Day(s) of challenge: Fifth week
- Exposure period:24 hours
- Test groups:10 males and 10 females
- Control group:5 males and 5 females
- Site: flank
Test
0.2 g per patch of the test item in vaseline
control group
vaseline only
- Evaluation (hr after challenge):
Twenty four and forty eight hours after removing the dressings, the challenge reactions were graded according to the Draize scoring scale

OTHER:
After the intradermal and the epidermal induction application skin irritation is normally induced by the adjuvant, the high test article concentration, or the sodium lauryl sulfate pretreatment. Because most of the reactions are treatment related and not test article related ,the reactions are
generally not described in the results section.
Positive control substance(s):
not required

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
2 mg/L
No. with + reactions:
20
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 2 mg/L. No with. + reactions: 20.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
2 mg/L
No. with + reactions:
20
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2 mg/L. No with. + reactions: 20.0. Total no. in groups: 20.0.

Any other information on results incl. tables

Under the experimental conditions employed, 100 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings. The test item is, therefore, classified as an extreme sensitizer in albino guinea pigs according to the grading of Magnusson and Kligman.

Score 24 hours after removal of the dressing

Male animals 156 157 158 159 160 161 162 163 164 165
Erythema score: 2 1 2 2 2 2 2 2 2 2
Edema score: 2 1 2 1 2 1 2 2 1 2
Female animals 171 172 173 174 175 176 177 178 179 180
Erythema score: 2 2 2 2 22 2 1 1 1 2
Edema score: 1 2 1 1 2 2 1 1 1 2

Score 48 hours after removal of the dressing

Male animals 156 157 158 159 160 161 162 163 164 165
Erythema score: 2 1 2 2 2S 2 2 2 2 2
Edema score: 2 2 2 1 3 2 2 2 2 2
Female animals 171 172 173 174 175 176 177 178 179 180
Erythema score: 2 2 2S 2 2S 2S 1 1 1 2S
Edema score: 2 2 3 2 3 3 2 2 2 3

S= scaling

Applicant's summary and conclusion

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

The test item has been tested according to the OECD 406 (Guinea pig maximisation test).

Under the experimental conditions employed, all the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.