reaction products of acetic anhydride and adipic acid

Endpoint summary

Description of key information

Skin irritation: Corrosive (acetic anhydride, rabbit)
Eye irritation: Serious eye damage due to irreversible effects (acetic acid; rabbit)
Respiratory irritation: Irritating (acetic acid, mouse) 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

No specific studies have been conducted for the target substance.The substance is composed of acetic anhydride (typical conc. ca. 7 wt. %), adipic acid, di-anhydride with bis (acetic acid) (typical conc. ca. 57 wt. %) and acetic acid (typical conc. ca. 33 wt. %). The main and the most hazardous component of this substance is acetic anhydride which has well-known corrosive and irritating effects on the eyes, skin and respiratory tract.

The weight of evidence approach is used to evaluate the irritation / corrosion properties of the target substance. The data from acetic anhydride and from hydrolysis products (acetic acid and adipic acid), are used in the assessment.

 

Skin irritation

Because of the well-known corrosive nature of acetic anhydride and acetic acid, the need for animal testing is difficult to justify.

 

In a study with rabbits, acetic acid was applied to shaved, intact skin for 4 h (Nixon et al., 1990). The sites were scored for erythema and oedema at 4, 24, 48 and 72 h. Primary Irritation Indices for a 3.3% aqueous solution of acetic acid was 0.5 and for a 10% aqueous solution was 1.1. Thus acetic acid was considered to be slightly irritating to rabbit skin at concentrations of 3.3 and 10%.

 

The neat acetic anhydride liquid administered to rabbits for 24h caused burns and blisters. Mild irritation was observed after open application OECD; SIDS (1997).

 

Eye irritation

No studies are conducted for the target substance. Based on the skin corrosive properties of acetic anhydride the target substance is classified as corrosive to skin (Skin Corr. 1B) with the risk of eye damage.

10% acetic acid in water was applied to rabbit eye (Jacobs and Martens, 1989). The observations conducted at 4, 24, 48, 72, 96 and 168 h showed to be irritating to the rabbit eye using the mean erythema score and % corneal swelling as measured using ultrasonic pachometry.

Instillation of 0.5 ml of a 1% acetic acid solution in the eyes of rabbits caused a severe burn (Smyth et al 1951). Solutions of 5 % induced injury in eyes of rabbits which were healed by 14 days while a 10 % solution resulted in severe permanent damage (European Commission, 2012).

Justification for selection of skin irritation / corrosion endpoint:
No specific study is selected since endpoint conclusion is based on the several studies from the decomposition products. Since the substance is classified as Skin. Corr. 1B, no study needed to conduct.

Justification for selection of eye irritation endpoint:
No specific study is selected since endpoint conclusion is based on the several studies from the decomposition products. Since the substance is classified as Skin. Corr. 1B, no study needed to conduct.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Effects on respiratory irritation: irritating

Justification for classification or non-classification

The target substance is classified to hazard class Skin Corr. 1B according to CLP Regulation 1272/2008.

This classification is in line with the classification of the constituents of the target substance. Acetic anhydride has harmonized classification for Skin Corr. 1B with specific concentration limit C≥25%. Acetic acid has also harmonized classification for Skin Corr 1B with specific concentration limit 25% ≤ C ≥ 90%.

 

Due to a reversible respiratory tract irritation observed in studies conducted for acetic anhydride the target substance will be classified for STOT-SE 3 H335.