3-[[2-(acetyloxy)ethyl][4-[(4-nitrophenyl)azo]phenyl]amino]propiononitrile

Endpoint summary

Description of key information

Not irritant to the skin of rabbits.

Not irritant to the eye of rabbits.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In the assessment of irritating potential, available data on target substance itself and on a read-across substance, i.e. Similar Substance 01, was used. Further details on the read across are reported in section 13.

In both studies, samples with low purity were tested. Apart from the dye, remaining components were mainly dispersants, salts and water.

Skin and eye irritation potentials were tested in rabbits by topical application and instillation, respectively.

Studies on Similar Substance 01 (purity 34.5 %), according to OECD guidelines 404 and 405, were available and were used as key study, based on a detailed description of procedures and results. Test substance was found to be not irritant to the skin and eye of rabbits.

Under test conditions, during the observation period, no indications of systemic toxicity nor mortality were reported.

A skin irritation study on target substance (purity 24 %) was available and was used only as supporting evidence due to the lack of details. Signs of erythema could not be assessed due to the substance-related staining. On intact skin, no signs of oedema were noted over the whole observation period in all rabbits. On scarified skin, signs of oedema were noted, which disappeared within 8-days.

An eye irritation study on target substance (purity 24 %) was available. No irritation of iris was noted; corneal opacity, conjunctivae chemosis and redness were seen in all rabbits. At day 8 of observation, slight redness was still present in 3/6 rabbits along with scar in one rabbit. Compared to the currently accepted OECD guideline 405, significant differences in procedure were present. In particular, no rinse of treated eye was reported and observations were done up to day 8 instead of day 21. On these bases, clear evaluation of such irritation effects was not possible; thus, such study was not used to the purpose of classification.

Further data on target substance was availaible. In particular, no skin and eye irritation reactions were noted using a sample with 18 % dye content. Due to the low purity and the lack of details, such data was only reported as a confirmatory evidence to lack of irritation potential.

Furthermore, available data on structural analogues, tested in presence of dispersants and inorganic salts, similarly to target substance and read across substance, showed no evidence of irritating potential for both skin and eye.

Justification for classification or non-classification

Skin Irritation

According to the CLP Regulation (EC 1272/2008), skin corrosion means the production of irreversible damage to the skin, and skin irritation means the production of reversible damage to the skin following the application of a test substance for up to 4 hours.

A substance has to be classified as category 1 (corrosive) if it produces destruction of skin tissue, namely, visible necrosis through the epidermis and into the dermis, in at least 1 tested animal after exposure up to a 4 hour duration.

 

A substance has to be classified as category 2 (irritant) if shows:

(1) mean value of ≥ 2,3 - ≤ 4,0 for erythema/ eschar or for oedema in at least 2 of 3 tested animals from gradings at 24, 48 and 72 hours after patch removal or, if reactions are delayed, from grades on 3 consecutive days after the onset of skin reactions; or

(2) inflammation that persists to the end of the observation period normally 14 days in at least 2 animals, particularly taking into account alopecia (limited area), hyperkeratosis, hyperplasia, and scaling; or

(3) in some cases where there is pronounced variability of response among animals, with very definite positive effects related to chemical exposure in a single animal but less than the criteria above.

 

As no effects in terms of erythema and oedema were reported, no classification within the CLP Regulation (EC 1272/2008) applied.

 

Eye Irritation

According to the CLP Regulation (EC 1272/2008), serious eye damage means the production of tissue damage in the eye, or serious physical decay of vision, following application of a test substance to the anterior surface of the eye, which is not fully reversible within 21 days of application .

Eye irritation means the production of changes in the eye following the application of test substance to the anterior surface of the eye, which are fully reversible within 21 days of application.

 

A substance has to be classified as category 1 (irreversible effects on the eye), If, when applied to the eye of an animal, a substance produces:

- at least in one animal effects on the cornea, iris or conjunctiva that are not expected to reverse or have not fully reversed within an observation period of normally 21 days; and/ or

- at least in 2 of 3 tested animals, a positive response of:

- corneal opacity ≥ 3 and/or

- iritis > 1,5 calculated as the mean scores following grading at 24, 48 and 72 hours after installation of the test material.

 

A substance has to be classified as category 2 (irritating to eye) if, when applied to the eye of an animal, a substance produces:

at least in 2 of 3 tested animals, a positive response of:

- corneal opacity ≥ 1 and/or

- iritis ≥ 1, and/or

- conjunctival redness ≥ 2 and/or

- conjunctival oedema (chemosis) ≥ 2

calculated as the mean scores following grading at 24, 48 and 72 hours after installation of the test material, and which fully reverses within an observation period of 21 days.

As irritation scores of treated eyes were all below the thresholds set by the CLP Regulation (EC 1272/2008), no classification applied.