Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
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: OECD-guideline and GLP-compliant
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
When this study was performed, the LLNA did not yet exist as an OECD testing guideline. OECD TG 429 was adopted in April 2002.
Species:
guinea pig
Strain:
Himalayan
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: RCC Ltd, Biotechnology & Animal Breeding Division, Wolferstrasse 4, CH-4414 Fullinsdorf / Switzerland
- Age at study initiation: 4 - 6 weeks
- Weight at study initiation: 304 - 371 g
- Housing: Individually in Makrolon type-4 cages with standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz)
- Diet (e.g. ad libitum): Pelleted standard Nafag Ecosan 845 25W4
- Water (e.g. ad libitum): Community tap water
- Acclimation period: One week for the control and test group under test conditions after health examination.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ±3 °C
- Humidity (%): 40-70 % (values above 70 % during cleaning process possible).
- Air changes (per hr): 10-15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12
Route:
intradermal
Vehicle:
corn oil
Concentration / amount:
5%
Adequacy of induction:
highest technically applicable concentration used
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
50 %
Day(s)/duration:
2
Adequacy of induction:
highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
0.5 %
Day(s)/duration:
1
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
10
Details on study design:
RANGE FINDING TESTS:
Intradermal injections: Four intradermal injections (0.1 ml/site) of a 1:1 (v/v) mixture of Freund's Complete Adjuvant/physiological saline were made into the shaved neck of one guinea pig. One week later intradermal injections (0.1 ml/site) were made into the clipped flank of the same guinea pig at concentrations of 5, 3 and 1 % of the test article in corn oil. Dermal reactions were assessed 24 hours later. Based on the results, a test article concentration of 5 % was selected for intradermal induction in the main study.
Epidermal applications: after 4 intradermal injections (as described above), 2 guinea pigs were exposed to the test article at 50, 25, 15 and 10 % in corn oil under occlusive conditions for 24 h. The reaction sites were assessed approximately 24 and 48 hours after removal of the bandage for erythema and oedema according to the method of Magnusson and Kligman. No highest non-irritating concentration could be determined after the epidermal pretest described above. Therefore, a second pretest was performed with two additional naive guinea pigs, treated in the same way as that described previously, with the concentrations of 5, 3, 1 and 0.5 % in corn oil. Based on the results obtained the concentration selected for induction and challenge in the main study was 50 % and 0.5 %, respectively.

MAIN STUDY
INDUCTION EXPOSURE (Intradermal injection, on day 1)
- Test groups:
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) The test article, at 5 % in corn oil.
3) The test article at 5 % in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
- Control group:
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
2) Corn oil
3) 1:1 (w/w) mixture of corn oil in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.
- Site: scapular region

INDUCTION EXPOSURE (Epidermal application, on day 8)
- No. of exposures: 1
- Exposure period: 48 h
- Test groups: A 2 x 4 cm patch of filter paper was saturated with approximately 0.3 g test article (50 % in corn oil) and placed over the injection sites under occlusive condition.
- Control group: same as described above with corn oil only (0.3 ml).
- Site: scapular area

CHALLENGE EXPOSURE
- No. of exposures: once
- Day(s) of challenge: on test day 22, two weeks after the epidermal induction application
- Exposure period: 24 h
- Test groups: Two patches (3x3 cm) of filter paper were saturated with 0.2 ml of test article at the highest non-irritating concentration of 0.5 % (left flank) and the vehicle only (corn oil applied to the right flank) using the same method as for the epidermal application.
- Control group: same as test group
- Site: dorsal skin from the scapular region
- Concentrations: highest non-irritating concentration of 0.5 %
- Evaluation (hr after challenge): 24 and 48

Challenge controls:
yes, 5 control animals were used as challenge controls
Positive control substance(s):
yes
Remarks:
2-mercaptobenzothiazole
Positive control results:
The positive control at a concentration of 10 % in mineral oil is considered to be an extreme sensitizer.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.5 %
No. with + reactions:
1
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.5 % . No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
0.5 %
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.5 % . No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Reading:
1st reading
Hours after challenge:
24
Group:
other: challenge control
Dose level:
0.5 %
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: challenge control. Dose level: 0.5 %. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
other: challenge control
Dose level:
0.5 %
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: challenge control. Dose level: 0.5 %. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: none.

- There were no deaths during the course of the study.

- No signs of systemic toxicity were observed in the animals.

- The body weight of the animals was within the range commonly recorded for animals of this strain and age.

- Control group: No skin reactions were observed in the animals when treated with either corn oil only or when treated with the test article at 0.5 % in corn oil.

- Test group: Discrete/patchy erythema was observed in one out of 10 animals at the 24-hour reading after treatment with the test article at 0.5 % in com oil. No skin reactions were observed in the animals treated with corn oil only.

Interpretation of results:
not sensitising
Remarks:
Migrated information
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

The skin sensitizing potential of the test article was assessed in a study conducted according to OECD guideline 406 (1993). Induction was performed intradermal (5% in corn oil) and one week later epicutaneous (50% in corn oil, 48 h, occlusive). Two weeks after epidermal induction animals were challenged epicutaneous for 24 h with 0.5% test substance in corn oil and corn oil alone under semi-occlusive conditions (RCC740068, 1999). Discrete/patchy erythema was observed in 1/10 animals after 24 h. No skin reactions were observed after 48 h in treated animals or in any animal treated with corn oil only. No signs of systemic toxicity were observed in the animals. Thus, the test substance was considered to be not sensitizing.


Migrated from Short description of key information:
A valid study on skin sensitization with the test substance is available. In a study conducted according to OECD guideline 406 discrete/patchy erythema was observed in 1/10 animals after 24 h (rabbit, RCC740068, 1999). No erythema was observed after 48 h. Thus, the test substance was not skin sensitizing.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC)

The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for skin sensitization under Directive 67/548/EEC.

                               

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008.