2,2'-azobis[2-methylbutyronitrile]

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

pre-GLP study. GPMT performed similar to current scientific principles

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Remarks:

The study was conducted according to the guideline in effect.

GLP compliance:

no

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

test was conducted before LLNA method was adopted

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-azobis[2-methylbutyronitrile]

EC Number:

236-740-8

EC Name:

2,2'-azobis[2-methylbutyronitrile]

Cas Number:

13472-08-7

Molecular formula:

C10H16N4

IUPAC Name:

2,2'-diazene-1,2-diylbis(2-methylbutanenitrile)

Details on test material:

- Purity: 96%

Specific details on test material used for the study:

Purite: 100%

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: not reported
- Age at study initiation: not reported
- Weight at study initiation: contol animals average weight - 508 g; test animals average weight - 518 g
- Housing: not reported
- Diet (e.g. ad libitum): not reported
- Water (e.g. ad libitum): not reported
- Acclimation period: not reported

ENVIRONMENTAL CONDITIONS: not reported

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal

Vehicle:

other: See Remark

Remarks:

Dimethyl phthalate (DMP)

Concentration / amount:

8% and 80% in DMP

Day(s)/duration:

4 weeks

Challenge

Route:

other: epicutaneous

Vehicle:

other: see Remark

Remarks:

Dimethyl phthalate (DMP)

Concentration / amount:

8% and 80% in DMP

Day(s)/duration:

24 and 48 hrs

No. of animals per dose:

10

Details on study design:

RANGE FINDING TESTS: No sensitisation was observed at 10, 21, 42, or 83% (w/v) when tested in 3 guinea pigs per concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 4
- Exposure period: 4 weeks
- Test groups: 1, 80% and an 8% suspension of the test material in the primary irritation test on same animal
- Control group: yes, no treatment
- Site: sacral intradermal injection
- Frequency of applications: 1 each week beginning 2 days after the test for primary irritation
- Duration: 4 weeks
- Concentrations: 0.1 ml of a 1.0% suspension in DMP,

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 2 days
- Exposure period: 24 hours and 48 hours
- Test groups: 1, 80% and an 8% suspension of the test material on same animal
- Control group: yes, At the same time 10 unexposed guinea pigs (controls) of the same age received identical topical applications.
- Site: shaved, intact shoulder skin.
- Concentrations: 0.05 ml of an 80% and an 8% suspension of test material in DMP
- Evaluation (hr after challenge): 24 hours and 48 hours

Challenge controls:

At the same time 10 unexposed guinea pigs (controls) of the same age received identical topical applications (0.05 ml of an 80% and an 8% suspension of test material in DMP).

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

all

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

no indication of skin sensitisation

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

all

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

none

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

The test substance caused no irritation on shaved intact skin of 10 guinea pigs at 24 or 48 hours in both the primary irritation test and in the sensitization challenge. None of the test guinea pigs showed a sensitization response.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

not sensitizing

Conclusions:

Not sensitising

This study and the conclusions which are drawn from it fulfill the quality criteria (validity, reliability, repeatability).

Executive summary:

The primary irritation test was conducted on 10 unexposed guinea pigs by applying and lightly rubbing in 0.05 mL of an 80% and an 8% suspension of the test material in DMP on shaved, intact shoulder skin. The induction phase began 2 days after the primary irritation test and continued for 4 weeks, one injection each week. After a 13-day rest period, the test guinea pigs were challenged for sensitization by applying and lightly rubbing in 0.05 mL of an 80% and an 8% suspension of test material in DMP on shaved, intact shoulder skin. The test substance caused no irritation on shaved intact skin of 10 guinea pigs at 24 or 48 hours. None of the test guinea pigs showed a sensitization response.