Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011-05-31 - 2011-07-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
3-methylpyrazole
EC Number:
215-925-7
EC Name:
3-methylpyrazole
Cas Number:
1453-58-3
Molecular formula:
C4H6N2
IUPAC Name:
3-methyl-1H-pyrazole
Test material form:
other: liquid

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
2.5, 5, 10, 25 %
No. of animals per dose:
4
Details on study design:
In the main assay 24 female CBA/Ca mice were allocated to six groups of four animals each:

- four groups received 3-Methylpyrazol at four different concentrations of 25 %, 10 %, 5 % or 2.5 %,

- the negative control group received the vehicle (AOO),

- the positive control groups received a-Hexylcinnamaldehyde (HCA) at concentration of 25 %.

Each substance was applied on the external surface of each ear (25 ^L/ear) of the animals for three consecutive days (Day 1, 2 and 3). There was no treatment on Days 4, 5 and 6. On Day 6, the cell proliferation in the local lymph nodes was measured by incorporation of tritiated methyl thymidine (3HTdR) and the obtained values were used to calculate stimulation indices (SI).
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Any other information on results incl. tables

Test Group

Measured

Group*

DPN

Stimulation

Name

DPM/group

DPM

(DPM/Node)

Index Values

Negative (vehicle) control:

5088

5038.5

629.8

1.0

AOO

 

 

 

 

Positive control

37158

37108.5

4638.6

7.4

25 %HCA in AOO

 

 

 

 

3-Methylpyrazol

-

-

-

-

25 %in AOO

 

 

 

 

3-Methylpyrazol

8887

8837.5

1104.7

1.8

10 %in AOO

 

 

 

 

3-Methylpyrazol

9676

9626.5

1203.3

1.9

5 %in AOO

 

 

 

 

3-Methylpyrazol

8151

8101.5

1012.7

1.6

2.5 %in AOO

 

 

 

 

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
In conclusion, under the conditions of the present assay 3-Methylpyrazol, tested at the maximum feasible concentration of 10 % and concentrations of 5 % and 2.5 % as formulations in a suitable vehicle (AOO), was shown to have no sensitization potential (non-sensitizer) in the Local Lymph Node Assay.
Executive summary:

In conclusion, under the conditions of the present assay 3-Methylpyrazol, tested at the maximum feasible concentration of 10 % and concentrations of 5 % and 2.5 % as formulations in a suitable vehicle (AOO), was shown to have no sensitization potential (non-sensitizer) in the Local Lymph Node Assay.