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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:
guideline study

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female

Study design: in vivo (non-LLNA)

Induction
Vehicle:
propylene glycol
Concentration / amount:
10%, 25% and 50%
Challenge
Vehicle:
propylene glycol
Concentration / amount:
10%, 25% and 50%

Study design: in vivo (LLNA)

Vehicle:
propylene glycol
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: The SI for 10, 25 and 50% were 1.9, 2.2 and 2.4. For a positive response, SI needs to be equal or more than 3.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: see Remark
Remarks:
No irritation was observed in any of the animals examined. Brown test substance remnants prevented scoring for erythema in all animals treated with the test substance. No oedema was observed in any of the animals examined. All nodes of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted. Body weights and body weight gain of experimental animals remained in the same range as controls over the study period. The slight body weight loss, noted in some animals, was considered not toxicologically significant. Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25 and 50% were 595, 677 and 721 respectively. The mean DPM/animal value for the vehicle control group was 306. No mortality occurred and no symptoms of systemic toxicity were observed in the animals of the main study. The SI values calculated for the substance concentrations 10, 25 and 50% were 1.9, 2.2 and 2.4 respectively. Test substance is not a sensitiser.

Any other information on results incl. tables

Comments:
The six monthly reliability check with Hexylcinnamaldehyde,
indicates that the Local Lymph Node Assay as performed at
NOTOX is an appropriate model for testing for contact
hypersensitivity.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Executive summary:

Test substance concentrations selected for the main study were based on the results of a preliminary study.

In the main study, three groups of five experimental animals were treated with test substance concentration concentrations of 10 %, 25 % or 50 % on three consecutive days, by open application on the ears. Five vehicle control animals were animals were similarly treated, but with vehicle alone (propylene glycol).

Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after 5 hours the draining (auricular) lymph nodes were excised. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for each group.

No irritation was observed in all of the animals examined. Brown test substance remnants prevented scoring for erythema in all animals treated with the test substance. No oedema was observed in any of the animals examined.

All nodes of the experimental and control groups were considered normal in size. No macroscopic abnormalities of the surrounding area were noted.

Mean DPM/animal values for the experimental groups treated with test substance concentrations 10, 25, and 50 % were 596, 677 and 721 respectively. The mean DPM/animal value for the vehicle control group was 306.

The SI values calculated for the substance concentrations 10, 25 and 50% were 1.9, 2.2 and 2.4 respectively.

Since there was no indication that the test substance could elicit an SI>= 3 when tested up to 50 %, it was established that the EC3 value (if any) exceeds 50 %.

The six monthly reliability checks with Hexylcinnamaldehyde, indicates that the Local Lymph Node Assay as performed at NOTOX is an appropriate model for testing for contact hypersensitivity.