Registration Dossier

Toxicological information

Skin sensitisation

Currently viewing:

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2001-04-02 to 200105-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes (incl. QA statement)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
study was already performed in 2001 and is sufficient for non-classification

Test material

Constituent 1
Chemical structure
Reference substance name:
N,N''-(4-methyl-m-phenylene)bis[N',N'-dimethylurea]
EC Number:
241-523-6
EC Name:
N,N''-(4-methyl-m-phenylene)bis[N',N'-dimethylurea]
Cas Number:
17526-94-2
Molecular formula:
C13H20N4O2
IUPAC Name:
3-[3-(dimethylcarbamoylamino)-4-methylphenyl]-1,1-dimethylurea
Constituent 2
Chemical structure
Reference substance name:
3-[3-(dimethylcarbamoylamino)-2-methylphenyl]-1,1-dimethylurea
Cas Number:
17607-23-7
Molecular formula:
C13H20N4O2
IUPAC Name:
3-[3-(dimethylcarbamoylamino)-2-methylphenyl]-1,1-dimethylurea
impurity 1
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
impurity 2
Reference substance name:
unknown
IUPAC Name:
unknown
Test material form:
solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Winkelmann GmbH, D-33178 Borchen
- Age at study initiation: no data
- Weight at study initiation: 300- 500 g
- Housing: The animals were barrier maintained (semi-barrier) in air conditioned rooms and were kept in groups in Terluran-cages on Altromin saw fiber bedding. Max. group size 10 animals
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: adequate

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3° C
- Humidity (%): 55±10%
- Air changes (per hr): 10x/hour
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
physiological saline
Concentration / amount:
5 % / 0.1 ml
Day(s)/duration:
7 d
Adequacy of induction:
highest technically applicable concentration used
Route:
epicutaneous, occlusive
Vehicle:
petrolatum
Concentration / amount:
25 % / 0.5 ml
Day(s)/duration:
48 h
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
petrolatum
Concentration / amount:
25 % / 0.5 ml
Day(s)/duration:
24 h
Adequacy of challenge:
highest non-irritant concentration
No. of animals per dose:
10 female test animals, 5 female control animals and 6 female animals for range finding
Details on study design:
RANGE FINDING TESTS: For the justification of dose levels a preliminary test as performed. Three animals were treated intradermally with 0.5%, 1%, 2.5%, 5% concentration ofthe test item and three animals were topically treated with 5%, 10%, 25% concentration of the test item.

MAIN STUDY
A. INDUCTION EXPOSURE
Three pairs of intradermal injections of 0.1 ml volume were given in the shoulder region which was cleared of hair so that one of each pair lies on each side of the midline.
- No. of exposures: 3
Induction: First Stage, Intradermal Injection
Test group: Day 0
Injection 1: Freund's Adjuvant complete, 1+1 (v/v) diluted with isotonic saline
Injection 2: Prepared test item
Injection 3: Prepared test item at a concentration of 50% (VN) in Freund's
Adjuvant complete, 1+1 (v/v) diluted with isotonic saline.

Control group : Day 0
Injection 1: Freund's Adjuvant complete, 1+1 (v/v) diluted with isotonic saline
Injection 2: NaCl 0,9%
Injection 3: NaCl 0,9% at a concentration of50% (VIV) in Freund's
Adjuvant complete, 1+1 (v/v) diluted with isotonic saline.

lnduction: Second Stage, Topical Application
Day 6: Test and control group
Approximately twenty-four hours before the topical induction application the test area, after close clipping was painted with 0.5 ml of 10% sodium lauryl sulfate in vaseline, in order to create a local irritation.

Test Group: Day 7
A patch was loaded with 0.5 ml of the test item at a 25% concentration, applied to the test area and held in contact by an occlusive dressing for 48 hours.
Control Group: Day 7
A patch was loaded with 0.5 ml of vehicle and applied to the test area and held in contact by an occlusive dressing for 48 hours.

- Exposure period: 7 days
- Test groups: 1
- Control group: 1
- Site: shoulder region

B. CHALLENGE EXPOSURE: topiccal application
- No. of exposures: 1
- Day(s) of challenge: 1
- Exposure period: 24 h
- Test groups: 1
- Control group: 1
- Site: flanks
- Concentrations: A patch loaded with 0.5 ml of the test item (25%) was applied to the left flank of the animals and, a patch loaded with 0.5 ml vehicle to the right flank (intraspecific control), respectively. The patches were held in contact by an occlusive dressing for 24 hours. At the end of the challenge skin was cleaned with the aid of moistened ganze patches.
- Evaluation (hr after challenge): 24 h, 48 h and 72 h
Approximately 21 hours after removing the patch the challenge area was cleaned and cleared of hair. Approximately 24 hours after removing of the patch the skin reaction was observed and recorded according to the grades shown below. Two more observations were recorded 48 and 72 hours after patch removal.

Challenge controls:
0.5 ml of the vehicle was applied to the right flank (intraspecific control).
Positive control substance(s):
yes
Remarks:
Mercaptobenzothiazole

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
25 %
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
25%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
25%
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
2 % (Induction I); 25 % (Induction II);15 % (Challenge)
No. with + reactions:
5
Total no. in group:
10
Clinical observations:
Erythema and Oedema
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
2 % (Induction I); 25 % (Induction II);15 % (Challenge)
No. with + reactions:
5
Total no. in group:
10
Clinical observations:
Erythema and Oedema
Remarks on result:
positive indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Considering the reported data of this sensitization test it can be stated that the test item TDI-Urone caused no reactions identified as sensitization.
Executive summary:

In a dermal sensitization study according to OECD 406 with TDI urone in 0.9%NaCl (5% TDI-Urone) and Vaseline (25% TDI-Urone), respectively, Hsd Poc:DH guinea pigs (10 females in the test group, 5 females in the control group and 6 females for range-finding study) were tested using the method of Guinea-Pig Maximisation Test.

During the induction phase the guinea pigs were intradermally injected with 5% TDI-Urone and, after treatment with sodium lauryl sulfate, topically treated with 25%TDI-Urone. After a latency of 2 weeks the animals were challenged with 25% TDI-Urone on the flank. The grade of skin reactions was compared to control animals, which were treated with isotonic saline resp. vaseline during the induction phase and, during the challenge phase with the test item, respectively.

No skin reactions were observed throughout the study. Therefore, the skin sensitization rate after application of TDI-Urone was 0 %. Under the test conditions TDI-Urone showed no sensitizing properties. Animals of the test group showed normal weight gain as compared to historical data and the animals of the control group.

In this study, TDI-Urone is not a dermal sensitizer.