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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
Lymph node weight and lymph node cell count was used to assess proliferation instead of radioactive labelling.
GLP compliance:
yes (incl. certificate)
Remarks:
LPT Laboratory of Pharmacology and Toxicology GmbH
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Dicumylperoxide
- Molecular formula (if other than submission substance): C18H22O2
- Substance type: white crystalline powder
- Physical state: solid
- Analytical purity: 99.5% (based on CoA)
- Purity test date: 07.12.2009
- Lot/batch No.: 44229 (receipt no.)

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories
- Age at study initiation: 12 weeks
- Weight at study initiation: 20-25 g
- Housing: singly in MAKROLON cages (type III)
- Diet (e.g. ad libitum): ssniff R/m-H V1534, ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: at least 5 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-3°C
- Humidity (%): 55+/-15%
- Air changes (per hr): Not reported
- Photoperiod (hrs dark / hrs light): 12h:12h

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Remarks:
given in report as (3+1, v/v)
Concentration:
10%, 25%, and 50% (w/w) in 25 µL
No. of animals per dose:
6 females
Details on study design:
RANGE FINDING TESTS:
perfomed with 1 animal each at 10, 25 and 50% (25µL/ear)

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response: Index for lymph node cell count above 1.4 and index for ear weight above 1.1
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
Mann & Whitney U-test , concentration-response-relationship examined by linear regression analysis using Pearsons's correlation coefficient

Results and discussion

Positive control results:
The positive control revealed a significant increase in lymph node cell count above the threshold of 1.4. Therefore, the test was considered valid.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: The simulation index for cell count did not exceed the threshold of 1.4. Hence, the test item is classified as not sensitising.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Lymph node weight and lymph node cell count was used to assess proliferation instead of radioactive labelling.

Any other information on results incl. tables

 

Parameter

Group 1, negative control

Group 2, 10%

Group 3, 25%

Group 4, 50%

Group5, positive control

Lymph node cell count

1

0.086

1.339

1.384

1.764*

Lymph node weight

1

1.400

1.909*

1.954*

2.127*

Ear weight

1

0.949

0.916*

0.888*

0.762*

Ear thickness

1

1.032

1.036

1.044

1.104

*: sign. at p<= 0.01

 

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The result of the LLNA test perfomed with dicumyl peroxide revealed that dicumyl peroxide is not senstizing to skin.
Executive summary:

Female mice were tested for sensitisation according to OECD Guideline 429. The result of the LLNA test indicate that dicumyl peroxide is not sensitizing to skin when tested at concentration up to 50% (25 µL/ear).