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

Endpoint summary

Description of key information

In rabbit dermal study the test substance did not induce skin irritation at a single dose of 500 mg.

Test in human also showed that this chemical was not a skin irritant. The test was performed with 2 days occlusion and 3 readings (usually on day 2, 3 and 4 - 6). This chemical (0.1 %) was applied to 173 patients, suspected occupational dermatoses. Skin irritative reaction was observed only in one patient.

There was an eye irritation study, in which application of this chemical at a single dose of 100 mg into the conjunctival sac, induced no irritation approximately 1, 24, 48 and 72 hours after administration.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1997

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

4 h

Observation period:

approximately one hour, 24, 48 and 72 hours after removal of the dressing

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

other information

Study period:

1997

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

GLP compliance:

no

Species:

other: human

Type of coverage:

occlusive

Vehicle:

other: petroleum ether

Amount / concentration applied:

0.1 % in petroleum ether

Duration of treatment / exposure:

2 days

Observation period:

3 readings (usually on irritant day 2, 3 and 4 -6)

Number of animals:

173

Remarks on result:

no indication of irritation

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

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 405 (Acute Eye Irritation / Corrosion)

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

100 mg

Observation period (in vivo):

approximately one hour, 24, 48 and 72 hours after administration

Details on study design:

eyes were not rinsed

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation

A single dose of 500 mg in original form of the substance was applied to the closely-clipped skin of the flank of rabbits for 4 hours, with semi-occlusive dressing. Cutaneous reaction was evaluated approximately one hour, 24 h, 48 h and 72 h after removel of the dressing. No indication of skin irritation was observed. (Elf Atochem, 1996)

Another test was performed with 2 days occlusion and 3 readings (usually on irritant day 2, 3 and 4 - 6). 0.1 % in petroleum ether was applied to 173 patients, who were suspected occupational dermatoses. Skin irritative reaction was observed only in one patient. (Kanerva, 1997)

IGW Elberfeld examined the skin irritating potential of the substance in rabbit and human. The neat substance was applied for 24 h and did not result in skin irritation. (IGW Elberfeld)

Rusin et al. observed no local signs of irritation or symptoms of adsorption after the application of the neat substance to the tails of 5 mice for 5 days (4 h exposure per day). (Rusin et al., 1958)

The Toxic Substances Control Act provides additional literature data on skin irritation. No irritation was observed when the test substance was applied as a 25 % and 10 % ointment in "Carbowax 1500" or as a 25 % and 10 % suspension in dimethylphthalate to the intact skin of albino guinea pigs (10 animals per group). The only finding recorded was an occasional mild erythema in 1 of 10 animal of the 25 % ointment group. In another study with guinea pigs, slight skin irritation (slight edema and grade 1 erythema) was observed. No finding at scoring at 1 and 2 weeks after application. No evidence of absorption was observed after application of the test substance under occlusive conditions. (TSCAT, 1984)

Eye Irritation

After gently pulling the lower lid away from the eyeball, a single dose of 100 mg in original form of the test substance was administered into the conjunctival sac of the left eye of a rabbit. The lower and upper eyelids were held together for about one second to avoid any loss of test substance. The right eye, which remained untreated, served as a control. The eyes were not rinsed and examined approximately one hour, 24 h, 48 h and 72 h after administration. No indication of eye irritation was observed. (Elf Atochem, 1996)

The Toxic Substances Control Act provides additional literature data on the eye irritation potential in rabbits. The test substance was instilled neatly (10 mg powder) or undiluted (0.1 mL of a 10 % suspension in propylene glycol) into each eye of each of the test rabbits (male). The left eye was washed 20 seconds after application, the right eye was treated without rinsing. Mild temporary conjunctival irritation (until up to 4 days after application) but not corneal or iritic injury was observed within a 7 -day observation period. In another study with rabbits, the test substance was slightly irritating. No further information on this study are provided. (TSCAT, 1984)

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. In skin and eye irritation studies the test item showed no irritating potential. As a result the substance is not considered to be classified for skin or eye irritation under Regulation (EC) No. 1272/2008, as amended for the tenth time in Regulation (EC) No. 2017/776.