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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

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: OECD guideline study conducted according to GPL.

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
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylpent-2-enal
EC Number:
210-789-5
EC Name:
2-methylpent-2-enal
Cas Number:
623-36-9
Molecular formula:
C6H10O
IUPAC Name:
2-methylpent-2-enal

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:
0, 25, 50 und 100%
No. of animals per dose:
5
Statistics:
For all statistical calculations SigmaStat for Windows (Version 2.0) was used. A One-Way-Analysis-of-Variance was used as statistical method. In case of significant results of the One-Way-ANOVA, multiple comparisons were performed with the Dunnett test. Statistical significance was set at the five per cent level (p < 0.05). The Dean-Dixon-Test and Grubb’s test were used for identification of possible outliers (performed with Microsoft Ex el 2003).

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Value:
12.96
Test group / Remarks:
25% 2-Methylpent-2-enal
Parameter:
SI
Value:
12.89
Test group / Remarks:
50% 2-Methylpent-2-enal
Parameter:
SI
Value:
16.37
Test group / Remarks:
100% 2-Methylpent-2-enal

Any other information on results incl. tables

 Test item concentration  Mean DPM per animal (2 lymph nodes)  SD  S.I.
Vehicle Control (acetone:olive oil (4+1 v/v))  792.1  275.5  1.00
 25% 2-Methylpent-2-enal  10264.9  2313.2  12.96
 50% 2-Methylpent-2-enal  10213.1 2925.8  12.89
 100% 2-Methylpent-2-enal  12966.9  1849.9  16.37

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Remarks:
Migrated information
Conclusions:
The test item 2-Methylpent-2-enal was found to be a skin sensitiser under the test conditions of this study.
Executive summary:

A test item is regarded as a sensitiser in the LLNA if exposure to one or more test item concentration results in a 3-fold or greater increase in incorporation of 3HTdR compared with concurrent controls, as indicated by the Stimulation Index (S.I.). The estimated test item concentration required to produce a S.I. of 3 is referred to as the EC3 value. In this study S.I. of 12.96, 12.89, and 16.37 were determined with the test item at concentrations of 25 and 50% (w/w), and 100% (undiluted test item) in acetone:olive oil (4+1 v/v), respectively. The mean DPM value was increased in the high dose group in comparison to the mid and low dose group. A statistically significant and biologically relevant increase in DPM values as well as in lymph node weight and lymph node cell count was observed in all test item treated groups in comparison to the vehicle control groups.