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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: Well documented study according to international accepted guidelines and GLP compliant.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report date:
2014

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:
2-ethylcyclopentane-1,3-dione
EC Number:
212-512-3
EC Name:
2-ethylcyclopentane-1,3-dione
Cas Number:
823-36-9
Molecular formula:
C7H10O2
IUPAC Name:
2-ethylcyclopentane-1,3-dione
Test material form:
solid: crystalline
Details on test material:
Test item: Ethyl-cyclopentanedioneCAS number: 823-36-9Batch number: S41196NPhysical state: Solid, crystalline substanceColuor: Almost whiteActive ingredient content (Calculated): 93.7%Storage: At a temperature of 15 to 30 °C

In vivo test system

Test animals

Details on test animals and environmental conditions:
Species and strain: CBA/Ca Ola Hsd miceSource: TOXI-COOP ZRT.Hygienic level at arrival: SPFHygienic level during the study: Good conventionalNumber of animals: 24 animals/main test (4 animals/treatment group)Sex: Female, nulliparous, non-pregnantAge of animals: Young adult mice; 10-11 weeks old (at start of the main test)Body weight range at starting: 17.8-23.6 gAcclimatization time: 14 daysAnimal health: Only healthy animals were usedHousing during acclimatization period: Grouped caging in small groupsHousing during the test: Grouped caging (4 animals/cage)Light: 12 hours daily, from 6.00 a.m. to 6.00 p.m.Temperature: 22 ± 3 °CRelative humidity: 30 – 70 %

Study design: in vivo (LLNA)

Vehicle:
dimethylformamide
Remarks:
AOO (acetone:olive oil, 4:1) for positive control
Concentration:
The test item was administered at three different concentrations (25; 10; 5 w/v%) according to the results of the dose range finding test.
No. of animals per dose:
4 animal/dose
Details on study design:
Selection of test item concentrations was based on the results of a formulation evaluation and also results of preliminary irritation/toxicity test to find an appropriate solvent and the maximum applicable concentration according to the relevant guidelines. Based on the preliminary test results the test item was examined in the main test at 25 %, 10 % and 5 % (w/v) concentrations as formulations in the selected vehicle of N,N-Dimethylformamide (DMF). Appropriate positive control (α-Hexylcinnamaldehyde [HCA] in 25 % (w/v) concentration), furthermore two negative control groups dosed with the vehicles of the test and positive control groups, respectively, were employed.The positive control item (25 % (w/v) HCA in Acetone: Olive oil 4:1 (v/v) mixture, AOO) induced the appropriate stimulation over the control, thus confirming the validity of the assay.
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: see Remark
Remarks:
The stimulation index (SI = the DPN of a treated (positive control or test item) group divided by the DPN of the respective negative control group) for each treatment group was also calculated. A stimulation index of 3 or greater is an indication of a positive result. When monotonic dose-response is seen, attempt is made to calculate EC3 (dose calculated to induce a stimulation index of 3) with the help of linear regression on dose-response relationship. All calculations were made by Microsoft Excel Software. (See Table1 for the values.)
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: see Remark
Remarks:
DPM (disintegration per minute) was measured for each treatment group. The measured DPM values were corrected with the background DPM value. The average of the two measured DPM values of 5 % (w/v) TCA solutions was used as the background DPM value. The results were expressed as DPN (DPM divided by the number of pooled lymph nodes). (See Table1 for the values.)
Parameter:
SI
Value:
1.5
Remarks on result:
other: Ethyl-cyclopentanedione 10% in DMF
Parameter:
SI
Value:
0.9
Remarks on result:
other: Ethyl-cyclopentanedione 5% in DMF
Parameter:
SI
Value:
1
Remarks on result:
other: Ethyl-cyclopentanedione 25% in DMF

Any other information on results incl. tables

Test Group Name

Measured

DPM/group

Group*

DPM

DPN

(DPM/Node)

Stimulation

Index Values

Vehicle control for the positive control: AOO

18071

18050.0

2256.3

1.0

Positive control:
25 % HCA
in AOO

86012

85991.0

10748.9

4.8

Ethyl-cyclopentanedione
25 %
in DMF

3957

3936.0

492

1.0

Ethyl-cyclopentanedione
10 % in DMF

5871

5850.0

731.3

1.5

Ethyl-cyclopentanedione
5 %
in DMF

3650

3629.0

453.6

0.9

Vehicle control for the test item: DMF

4019

3998.0

499.8

1.0

 *Group DPM = measured DPMgroup- average DPMbackground

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Migrated information
Conclusions:
In conclusion, under the conditions of the present Local Lymph Node Assay, Ethyl-cyclopentanedione (CAS No. 823-36-9) tested at the maximum attainable concentration of 25 % (based on solubility) and at concentrations of 10 % and 5 % (w/v) as formulations in an appropriate vehicle (DMF) was shown to have no skin sensitization potential.

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