2,6-dibromo-4-cyanophenyl heptanoate

Endpoint summary

Description of key information

Key, M-280125-01-1; Guinea Pig Maximisation Test (guinea pig, EPA 81-6, GLP): skin sensitizing

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

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

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.

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

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%

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

Positive control results:

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

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

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

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

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

Key result

Reading:

other: no reading was performed

Group:

negative control

Remarks on result:

not measured/tested

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. 

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.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The skin sensitizing properties of the test substance were evaluated in male guinea pigs in compliance with GLP and according to EPA Guidelines 81-6 (M-280125-01-1). Groups of 10 guinea pigs were exposed to the test substance or 0.06% of dinitrochlorobenzole, which served as positive control .In total, the substances were applied to the clipped skin 10 times during induction and once for challenge. Briefly, 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 48 h after treatment.

 

The application was performed under an adhesive patch for a 6 h on Days 1, 3, 6, 8, 10, 13, 15, 17, 20, 22 and 36. The test substance induced slight erythema in 1/10 of the test sites 24 h following the first treatment. Slight to well-defined erythema and very slight edema were produced in a majority of animals 24 and 48 h following the challenge dose. A sensitizing reaction was produced by the 10 % solution of the test material in ethanol in 8/9 animals. The positive control substance produced a sensitizing reaction in Guinea pigs and thereby confirmed the sensitivity of the test system. One animal of the test material group died on day 10 of the study. This death is not believed to be related to the test material. Under the test conditions, despite the absence of an independent vehicle control group the test substance was considered to exhibit skin sensitizing properties.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The studies were performed according to GLP and are considered valid and reliable. Under the conditions tested, the test item induced skin sensitization in guinea pigs. Therefore, CLP/EU GHS criteria are met and the substance is classified as Skin sensitising category 1 according to Regulation (EC) No 1272/2008 and Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation, Index No. 607-427-00-7).