Ethyl and methyl cyanoacrylates have a sharp odour and are eye and nasal irritants, especially in enclosed spaces or where large volumes of cyanoacrylate are present.
This high volatility of cyanoacrylates can lead to the formation of a white ‘bloom’ adjacent to the bond line (see Section 10.2.6). Alkoxy ethyl cyanoacrylates with a high molecular weight are available that virtually eliminate the odour and minimise the blooming. However, these high-molecular-weight products are slower curing and do not always offer the same adhesion performance as the standard ethyl grades. In some applications a slower curing product is useful as it can give the operator more time to align component parts during the assembly process.