Registration Dossier

Administrative data

Description of key information

In an in vivo skin irritation study (similar to OECD Guideline No 404), the overall mean scores obtained with nopl acetate at 24, 48 and 72 h were 1.2 and 0.9 for erythema and oedema, respectively.
In a BCOP test (Bovine Corneal Opacity and Permeability) performed according to OECD Guideline No 437, negative results were obtained with nopyl acetate. In an in vitro eye irritation study on human reconstructed corneal epithelium model, the exposure time to nopyl acetate that caused 50% of cell mortality was 141.01 min.

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:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

In a skin irritation study performed similarly to OECD 404 Guideline on eight New Zealand White rabbits, nopyl acetate produced marginal to fairly distinct erythema, marginal to slight oedema, and slight to fairly distinct cracking and scaling. When using an equivalence between this scoring scale and OECD 404 scoring system, the overall mean scores at 24, 48 and 72 h were 1.2 and 0.9 for erythema and oedema, respectively. The result was negative. There is no requirement to conduct additional skin irritation tests with nopyl acetate, as negative results were obtained in an appropriate test system.

In an in vitro eye irritation study performed according to OECD 437 Guideline and in compliance with GLP, 750 µL of nopyl acetate were applied directly to isolated bovine corneas (32°C for 10 min). The opacity and permeability values were combined to obtain an in vitro irritancy score (IVIS).

IVIS nopyl acetate = 0.0.

In an in vitro eye irritation study performed in compliance with GLP, 30 µL of nopyl acetate were applied to a human reconstructed corneal epithelium model (in duplicate) for 10 min, 1 h and 3 h at room temperature. For each treated tissue the viability was expressed as the mean percentage of cellular viability relative to the negative control and the exposure time that causes 50% of cell mortality (T50) was determined by linear regression analysis.

T50 nopyl acetate = 141.01 min. The substance was considered as slightly irritating to eyes.


Justification for selection of skin irritation / corrosion endpoint:
Only one detailed study available for this endpoint.

Justification for selection of eye irritation endpoint:
Only one study assessing the irritant potential of the substance.

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

In an in vivo skin irritation study (similar to OECD Guideline 404), nopyl acetate induced only slight skin irritation in rabbits. As the overall mean scores for erythema and oedema were lower than 2, nopyl acetate is not classified for skin irritation/corrosion according to Directive 67/548/EEC and CLP Regulation (EC) No. (1272-2008).

In an in vitro eye irritation study on a human reconstructed corneal epithelium model, the exposure time that caused 50% of cell mortality (T50) was 141.01 min. The T50 value of nopyl acetate was between 60 and 180 min therefore it was considered as slightly irritant. Without clear correspondance between results of this test and common classification criteria, a conservative approach is adopted and nopyl acetate is classified as irritant "R36: irritating to eyes" according to Directive 67/548/EEC and irritating to eyes Category 2 according to CLP Regulation (EC) No 1272/2008.