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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: 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:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
Test item: 4-chloro-4’-fluorobutyrophenoneCAS No.: 3874-54-2Batch No.: 2607Physical state: liquidColour: yellowish greenStorage: cool, dry place in a tightly closed container

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
Source: TOXI-COOP ZRT.Hygienic level at arrival: SPFHygienic level during the test: Good conventionalNumber of animals: 32 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: 17.9-22.4 gAcclimatization time: 7 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 groups
Concentration:
The test item was administered at four different concentrations (100; 50; 25; 10 w/v%) according to the results of the dose range finding test.
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 tests to find an appropriate vehicle and the maximum applicable concentration according to the relevant guidelines [1-2]. Based on the preliminary test results 4-chloro-4’-fluorobutyrophenone was tested in the LLNA at concentration of 100 % as the undiluted test item and at 50 %, 25 % and 10 % (w/v) concentrations as formulations in DMF. Appropriate positive control (α-Hexylcinnamaldehyde [HCA] in 25 % (w/v) concentration), furthermore three negative control groups dosed with physiological saline (as naive control group), or 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

Positive control results:
The positive control group animals were treated with 25 % (w/v) HCA solution (dissolved in AOO) concurrent to the test item groups. No mortality, cutaneous reactions or signs of toxicity were observed in the positive control group.Significant lymphoproliferative response (SI ≥ 3) was noted for HCA (SI = 15.3). The results of the positive control item demonstrated appropriate performance of the test in accordance with the relevant guidelines and confirmed validity of the assay.

In vivo (LLNA)

Results
Key result
Parameter:
EC3
Value:
>= 13 - <= 17
Remarks on result:
other: EC3 value based on regression curve analysis was calculated.

Any other information on results incl. tables

Test Group Name

Measured

DPM/group

Group*

DPM

DPN

(DPM/Node)

Stimulation

Index Values

Naive control: physiological saline

2337

2314.0

289.3

1.0

Vehicle control for the positive control: AOO

12954

12931.1

1616.4

1.0

Positive control:
25 % HCA
in AOO

197314

197291.0

24661.4

15.3

4-chloro-4’-fluorobutyrophenone
100% (
undiluted)

144994

144971.0

18121.4

62.6

4-chloro-4’-fluorobutyrophenone
50 %
in DMF

128114

128091.0

16011.4

14.8

4-chloro-4’-fluorobutyrophenone
 
25 % in DMF

101034

101011.0

12626.4

11.7

4-chloro-4’-fluorobutyrophenone
10 % in DMF

10690

10667.0

1333.4

1.2

Vehicle control for the test item: DMF

8658

8635.0

1079.4

1.0

*Group DPM = measured DPMgroup- average DPMbackground

Applicant's summary and conclusion

Interpretation of results:
Category 1 (skin sensitising) based on GHS criteria
Remarks:
Migrated information
Conclusions:
Under the conditions of the present Local Lymph Node Assay, 4-chloro-4’-fluorobutyrophenone (CAS No. 3874-54-2) tested at the maximum applicable concentration of 100 % (as the undiluted test item) and at concentrations of 50 %, 25 % and 10 % (w/v) as formulations in an appropriate vehicle (DMF) was shown to have skin sensitization potential. The calculated EC3 values (based on dose-response and regression curve analysis) were 13 % and 17 % (w/v), in this LLNA, respectively. Based on the EC3 values the test item was considered a weak sensitizer according to the published data.According to GHS classification criteria (EC3 > 2%) the substance is classified as skin senzitization 1B sub-category.