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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From December 06, 1995 to January 05, 1996
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes (incl. QA statement)
Type of study:
Buehler test
Justification for non-LLNA method:
The study was conducted before the requirement for LLNA testing came into force.

Test material

Constituent 1
Chemical structure
Reference substance name:
Didecyldimethylammonium chloride
EC Number:
230-525-2
EC Name:
Didecyldimethylammonium chloride
Cas Number:
7173-51-5
Molecular formula:
C22H48N Cl
IUPAC Name:
N,N-Didecyl-N,N-dimethylammonium chloride
additive 1
Chemical structure
Reference substance name:
Propan-2-ol
EC Number:
200-661-7
EC Name:
Propan-2-ol
Cas Number:
67-63-0
Molecular formula:
C3H8O
IUPAC Name:
propan-2-ol
additive 2
Chemical structure
Reference substance name:
Water
EC Number:
231-791-2
EC Name:
Water
Cas Number:
7732-18-5
Molecular formula:
H2O
IUPAC Name:
water
Test material form:
liquid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River, Germany
- Age at study initiation: Approx. 5 wk
- Weight at study initiation: 381 - 463 grams
- Strain: Dunkin Hartley strain, albino guinea pig (SPF-quality)
- Number of animals per group: 20 animals tested
- Control animals: Yes: 10 animals

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
Induction: 2% test substance (10 mg active substance/mL) (causing mild to moderate irritation)
Challenge: 1% test substance (5 mg active substance/mL) (maximum non-irritant concentration)
Challenge
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
Induction: 2% test substance (10 mg active substance/mL) (causing mild to moderate irritation)
Challenge: 1% test substance (5 mg active substance/mL) (maximum non-irritant concentration)
No. of animals per dose:
Test group: 20 animals
Control group: 10 animals
Details on study design:
RANGE FINDING TESTS: Yes: The test system, procedures and techniques were identical to those used during the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Test groups: Yes
- Control group: Yes
- Frequency of applications: Day 1, 8 and 15
- Duration: 6 h (after 6 h, the dressing was removed and residual test substance removed using a tissue moistened with tap water)
- Concentrations: 0.5 mL of a 2 % test substance concentration

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Day 29
- Concentrations: 1% test substance
- Evaluation (hr after challenge): 24h, 48 h after challenge


Positive control substance(s):
yes
Remarks:
1-Chlor-2,4-dinitrobenzol

Results and discussion

Positive control results:
All the positive control animals showed positive reaction after 24 h of challenge.

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
-
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
-
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
1%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
Minimal skin reactions
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
1%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
-
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
10%
No. with + reactions:
9
Total no. in group:
9
Clinical observations:
-
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
10%
No. with + reactions:
9
Total no. in group:
9
Clinical observations:
-
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

- Slight to severe oedema, well defined to severe erythema and necrotic areas were observed in the treated skin areas in the experimental animals after the third 6 h epidermal induction exposure (Day 15).

- In the challenge phase minimal skin reactions were noted in two test and two control animals, 24 h after exposure only. 

- Taking into account the intensity of the response and comparing the test and the control animals it is concluded that the test material does not cause hypersensitisation in the guinea pig when tested according to Buehler (0% response).

Applicant's summary and conclusion

Conclusions:
Under the study conditions, the test substance was considered to be non sensitising in guinea pigs.
Executive summary:

A study was conducted to determine the skin sensitisation potential of the test substance, DDAC (51.3% active in hydroalcoholic solution), according to OECD Guideline 406 and EU Method B6, using Buehler test, in compliance with GLP. Test substance concentrations (in distilled water) selected for the main study were based on the results of a preliminary study. 20 experimental animals were treated on three occasions (6 h epidermal exposures on Day 1, 8 and 15) with a 2% test substance concentration and 10 control animals were treated with the vehicle only. 14 d after the last induction exposure, all animals were challenged with a 1% test substance concentration and the vehicle. The test sites were evaluated 24 and 48 h after challenge. Slight to severe oedema, well defined to severe erythema and necrotic areas were observed in the treated skin areas in the experimental animals after the third induction exposure (Day 15). In the challenge phase, minimal skin reactions were observed in 2 experimental and 2 control animals, 24 h after exposure. Taking into account the intensity of the responses and comparing these with the skin reactions seen in the control animals, it was considered that no experimental animals had induced hypersensitivity to test substance. These results lead to a sensitisation rate of 0%. All the positive control animals showed positive reaction after 24 and 48 h of challenge. Under the study conditions, the test substance was considered to be non sensitising in guinea pigs (Pels Rijken, 1996).