2,2'-dimethyl-2,2'-azodipropiononitrile

Endpoint summary

Description of key information

It has been shown that the test substance was not a skin sensitizer in a guinea pig maximization test. In this study, intradermal injection of this chemical at 0.1 % and topical application at 500 mg were performed as an induction, and topical application of this chemical undiluted at 500 mg as challenge did not induce any response.

Allergic patch test in human also showed that this chemical was not a skin sensitizer. The test was performed with 2 days occlusion and 3 readings (usually on day 2, 3 and 4 - 6). The chemical was applied at 1.0 % to 173 patients, that were suspected occupational dermatoses. No allergic reaction was observed.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1996

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

study was conducted before implementation of LLNA-method

Species:

guinea pig

Strain:

Dunkin-Hartley

Route:

intradermal

Vehicle:

paraffin oil

Concentration / amount:

0.1 %

Day(s)/duration:

day 1 / 7 days

Adequacy of induction:

not specified

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

500 mg

Day(s)/duration:

day 8 / 48 h

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

500 mg

Day(s)/duration:

24 hours

Adequacy of challenge:

not specified

Details on study design:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Exposure period: 12 days
- Control group: treatment with vehicle only
- Site: intradermal injection in the dorsal region between the shoulders, topical application to the same site
- Frequency of applications: day 1 and day 8
- Duration: 12 days
- Concentrations: 0.1 % in vehicle for intradermal injection and 500 mg undiluted test substance

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 24 h
- Exposure period: 24 h
- Control group: treatment with vehicle only
- Concentrations: 500 mg undiluted test substance
- Evaluation (hr after challenge): 24 and 48 hours after challenge application

Remarks on result:

no indication of skin sensitisation

Interpretation of results:

GHS criteria not met

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1997

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

Patients are patch tested. Patch testing was performed with 2 days occlusion and 3 readings (usually on day 2, 3 and 4 - 6). Allergic reactions were scored according to ICDRG recommendations, +, ++ and +++ reactions being considered allergic. Irritant reactions were also recorded. Reactions scored as doubtful (?+) or irritant (IR) were classified as irritant.

GLP compliance:

no

Type of study:

patch test

Justification for non-LLNA method:

study was conducted before implementation of LLNA-method

Species:

other: human

Details on study design:

Patch testing was performed with 2 days occlusion and 3 readings (usually on day 2, 3 and 4 - 6).

Remarks on result:

no indication of skin sensitisation

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The skin sensitizing potential was examined in a guinea pig maximization test. On day 1, 0.1 % in paraffin oil or the vehicle was injected intradermally in the dorsal region between the shoulders. On day 7, the same region received a topical application of sodium lauryl sulfate in vaseline in order to induce local irritation. On day 8, topical application of undiluted substance (500 mg) or the vehicle to this same site was performed with an occlusive dressing for 48 hours. After rest period of 12 days, all animals were challenged by a topical application of undiluted substance (500 mg) and the vehicle to the right and the left flank, respectively. This application was held for 24 hours with an occlusive, hypoallergenic dressing. Skin reaction was evaluated approximately 24 and 48 hours after challenge application. The challenge did not induce any response and therefore, the substance is not considered to cause skin sensitization in this test. (Elf Atochem, 1996)

Another test was performed with 2 days occlusion and 3 readings (usually on day 2, 3 and 4 - 6). 1.0 % in petroleum ether was applied to 173 patients, who were suspected occupational dermatoses. No allergic reaction was observed. (Kanerva, 1997)

The Toxic Substances Control Act provides additional literature data. No skin sensitization was observed when the test substance was applied as a 25 % ointment in "Carbowax 1500" to the abraded skin of 10 albino guinea pigs (series of 9 induction-applications followed by challenge-application after a 2 -week rest period). (TSCAT, 1984)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. No local reactions were observed in a guinea pig maximization test and the substance showed no allergic reaction in humans. Therefore, the substance does not require classification as a skin sensitizer under Regulation (EC) No. 1272/2008, as amended for the tenth time in Regulation (EC) No. 2017/776.