Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
05 May - 04 June 1987
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study, tested with the source substance CAS 16470-24-9. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (Dec 2012)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Pirbright White Strain (Tif: DHP)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: CIBA-GEIGY Ltd. Tierfarm, 4334 Sisseln, Switzerland
- Age at study initiation: approximately 10 weeks old
- Weight at study initiation: between 313 to 422 g
- Housing: individually housed in Macrolon cages (Type 3)
- Diet: standard guinea pig pellets NAFAG No. 846, Gossau SG, ad libitum
- Water: fresh water, ad libitum
- Acclimation period: guinea pigs were reported to be acclimatized, but number of days was not reported

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30 - 70 %
- Photoperiod: 12 hours light cycle day

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: see concentration
Concentration / amount:
Concentration of the test substance in physiological saline and adjuvant mixture: 1% (intradermal induction)
Approximately 0.4 g paste of 30% test substance in vaseline (epidermal induction)
Approximately 0.2 g paste of 10% test substance in vaseline (epidermal challenge)
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: see concentration
Concentration / amount:
Concentration of the test substance in physiological saline and adjuvant mixture: 1% (intradermal induction)
Approximately 0.4 g paste of 30% test substance in vaseline (epidermal induction)
Approximately 0.2 g paste of 10% test substance in vaseline (epidermal challenge)
No. of animals per dose:
10 males and 10 females per group
Details on study design:
INDUCTION PROCEDURES
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.

First Induction, intradermal application:
Three pairs of intradermal injections (0.1 mL per injection) were made simultaneously into the shaved neck of the guinea pigs as follows:
- adjuvant and saline (1:1)
- test compound in physiological saline
- test compound in the adjuvant saline mixture
Concentration of in physiological saline and adjuvant mixture: 1%

Second Induction, epidermal application:
One week later the test substance was incorporated in vaseline and applied on a filter paper patch to the neck of the animals (patch 2 x 4 cm; occluded administration for 48 hours). The application sites were pretreated the day before with 10% sodium lauryl sulfate (open application). Dose of application: approx. 0.4 g paste of 30% test substance in vaseline.

CHALLENGE
Two weeks after the epidermal induction application the animals were tested on the flank with test substance in vaseline and the vehicle alone (patch 2 x 2 cm; occluded administration for 24 hours). Dose of application: approx. 0.2 g paste of 10% test substance in vaseline. The concentrations of the test compound for the induction and challenge periods were determined on separate animals.

CONTROL GROUP
A control group was treated with adjuvant and the vehicle during the induction period.

IRRITATION POTENTIAL
Separate animals were treated with test item for the evaluation of the primary irritation threshold concentration. The tested concentrations of 10 and 30% of test item in vaseline did not induce erythema reactions. 10% was used as a sub-irritant concentration for the challenge application, to exclude nonspecific reactions in the adjuvant treated animals (s. Magnussen, 1980).

OBSERVATIONS and RECORDS
Twenty four hours after removing the dressings, the challenge reactions were graded according to the Draize scoring scale.
A second evaluation was made 48 hours after removing the dressings. The sensitizing potential of the test compound was classified according to the grading of Magnusson and Kligman. The body weight was recorded at start and end of the test.
Challenge controls:
A control group was treated with adjuvant and the vehicle during the induction period. During the challenge period the group was treated with the vehicle as well as with the test compound (at least 10 animals) to control the maximal sub-irritant concentration of the test compound in adjuvant treatedanimals.
Positive control substance(s):
yes
Remarks:
Paraphenylene-diamine or Potassium-dichromate.

Results and discussion

Positive control results:
The sensitivity of the strain is checked every six months with Paraphenylene-diamine or Potassium-dichromate. The results of the latest reliability check was not provided in the report.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
10 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 10 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
10 %
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10 %. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Any other information on results incl. tables

Under the experimental conditions employed, 0% of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

Number of positive animals per group after occlusive epicutaneous application:

after 24 hours after 48 hours
Control group
vehicle control 0/20 0/20
test compound 0/20 0/20
Test group
vehicle control 0/20 0/20
test compound 0/20 0/20

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: not classified
DSD: not classified
Executive summary:

Method

A sensitization test in albino guinea pigs was performed to determine the contact allergenic potency of the test compound in albino guinea pigs. This test was based on the OECD Guideline No. 406, adopted May 12, 1981, by the OECD council.

Results

Under the experimental conditions employed, 0 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

Conclusion

According to the CLP Regulation, a substance is classified as skin sensitiser when in the Guinea pig maximisation test the response of at least 30 % of the animals is considered as positive.

In the current experiment none of the animals tested showed any skin reaction.