2,6-dibromo-4-cyanophenyl heptanoate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Jul - 1 Sep 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPP 81-6 (Skin Sensitisation)

Principles of method if other than guideline:

Ten animals were treated with 0.5 ml of 2,4 dinitrochlorobenzene (0.06% w/v solution in ethanol, positive control) and 10 animals were treated with the test material in the following manner: treatments 1 through 3: 0.5 ml of the undiluted test substance applied to the left front test side; treatments 4 through 6: 0.5 ml of a solution of the test substance in ethanol (50% v/v) applied to the left rear test side; treatments 7 through 10 (applied to the right front test side) and the challenge treatment (applied to the right rear test side): 0.5 ml of a solution of the test substance in ethanol (10% v/v). Observations on skin reactions were made 24 and 48h after treatment.

GLP compliance:

yes

Type of study:

not specified

Justification for non-LLNA method:

The study was initiated prior to the implementation of the LLNA method.

Test material

Test material information

Constituent 1

Reference substance name:

2,6-dibromo-4-cyanophenyl heptanoate

EC Number:

260-300-4

EC Name:

2,6-dibromo-4-cyanophenyl heptanoate

Cas Number:

56634-95-8

Molecular formula:

C14H15Br2NO2

IUPAC Name:

2,6-dibromo-4-cyanophenyl heptanoate

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Sprague Dawley, Inc., Houston. Texas
- Age at study initiation: young adults
- Weight at study initiation: 255 - 325 g
- Housing: in groups of five in suspended, wire bottom, stainless steel cages
- Diet: Purina Guinea Pig Chow, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 8 days
- Indication of any skin lesions: no

ENVIRONMENTAL CONDITIONS
- Temperature (°C): not reported
- Humidity (%): not reported
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): not reported

INLIFE DATES From: 18 Jul To: 1 Sep 1989

Study design: in vivo (non-LLNA)

Induction

Route:

epicutaneous, occlusive

Vehicle:

other: Ethanol

Concentration / amount:

undiluted
50% v/v
10% v/v

Day(s)/duration:

undiluted: three treatments, Days 1, 3, 6 50%: three treatment, Days 8, 10, 13 10%: four treatments, Days 15, 17, 20, 22

Adequacy of induction:

other: the undiluted test material was the highest non-irritating level of the test material (as described in a previous study), due to skin irritation observed after treatments 3 and 6, the concentrations for the following treatments were reduced to 50 and 10%

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: Ethanol

Concentration / amount:

10% v/v

Day(s)/duration:

Day 36

Adequacy of challenge:

not specified

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: A pre-test was conducted, in which the undiluted material did not cause irritation.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10 (3 x undiluted, 3 x 50%, 4 x 10%, the concentrations have been lowered to 10% due to signs of irritation)
- Exposure period: Day 1 - 22
- Test groups: one test group, treated with the test substance as explained below. Administered volume was 0.5 mL.
- Positive control group: 0.06% dinitrochlorobenzol in ethanol
- Site: back of the trunk 3.8 x 5 cm, for the first three treatments, the patch was placed on the left front quadrant of the exposure area, with the beginning of Day 4, the test site was changed to the left rear quadrant, beginning at treatment 7 (Day 15), the test site was changed to the right front quadrant. The test site for the positive control substance remained unchanged.
- Frequency of applications: all 2 - 3 days
- Duration: 6 h
- Concentrations: undiluted (three treatments), 50% (three treatments), 10% (four treatments)

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 36
- Exposure period: 6 h
- Test groups: All animals were treated in a manner identical to the previous 10 treatment days, with the addition of a challenge test site placed laterally on the right rear quadrant of the exposure area with the edge of the gauze pad adjacent to the midline of the back
- Positive control group: 0.06% dinitrochlorobenzol in ethanol
- Site: right rear
- Concentrations: 10% v/v
- Evaluation (hr after challenge): 24, 48

OTHER:
The animals were observed for clinical signs at least once daily throughout the entire study period. Body weights were recorded on Day 0 and at the end of the study (Day 38).

Challenge controls:

None

Positive control substance(s):

yes

Remarks:

1-Chloro-2.4-dinitrobenzene (Dinitrochlorobenzol), 0.06% w/v in ethanol

Results and discussion

Positive control results:

Application of the positive control substance induced skin sensitisation thereby validating the test system.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Induction: undiluted, 50%, 10% Challenge: 10%

No. with + reactions:

8

Total no. in group:

9

Clinical observations:

Erythema score 1 (4 animals at the challenge side (right rear)) and 2 (4 animals at the challenge side (right rear)), Edema score 1 (5 animals at the challenge side (right rear))

Remarks on result:

positive indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction: undiluted, 50%, 10% Challenge: 10%

No. with + reactions:

7

Total no. in group:

9

Clinical observations:

Erythema score 1 (5 animals at the challenge side (right rear)) and 2 (2 animals at the challenge side (right rear)), Edema score 1 (5 animals at the challenge side (right rear))

Remarks on result:

positive indication of skin sensitisation

Results 3

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.06% Dinitrochlorobenzole

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

Erythema score 1 (5 animals at the challenge side (right rear)), 2 (1 animal at the challenge side (right rear)) and 3 (2 animals right front), Edema score 1 (5 animals at the challenge side (right rear))

Remarks on result:

positive indication of skin sensitisation

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

0.06% Dinitrochlorobenzole

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

Erythema score 1 (5 animals at the challenge side (right rear)), Edema score 1 (2 animals at the challenge side (right rear))

Remarks on result:

positive indication of skin sensitisation

Results 5

Key result

Reading:

other: no reading was performed

Group:

negative control

Remarks on result:

not measured/tested

Any other information on results incl. tables

One animal of the test group was found dead on Day 10 of the study, this was not believed to be related of test material. The gross necropsy-examination revealed signs of nasal discharge and salivation; red/black mucoid material and green slurry in the stomach, and brown mucoid material in the small intestine.

 

All animals gained weight during the study. 

 

The treatment group showed slight to well defined erythema and very slight to slight edema already during the induction phase of the study. Individual scores and average skin reaction scores can be found in Attachment 1 and 2. 

Applicant's summary and conclusion

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

The study was performed according to EPA Guidelines 81-6 and GLP and is considered valid and reliable. Under the test conditions chosen, the test substance produced a sensitizing reaction to the skin of the Guinea pig.