Drying of linseed oil paints:: a laboratory study of aldehyde emissions

The effects of temperature, air humidity, air exchange rate, artificial light and fatty acid constitution on the emissions of aldehydes from linseed oil paint were investigated. Experiments were designed using a multivariate approach and data were analysed using different projection methods (principal component analysis, partial leastsquares). Paints used were produced out of two different types of oils, where the fatty acid chains were either mainly linoleic or linolenic acid. The paints were applied onto glass plates and dried in chambers with a controlled climate. Aldehydes were sampled using silica gel impregnated with 2,4-dinitrophenylhydrazine and analysed by HPLC with UV and MS detection. Consecutive sampling of aldehydes every eighth hour as well as total aldehyde sampling was performed during the first 5 days after application of the paints. Hexanal and propanal were the dominating aldehydes emitted for linoleic and linolenic acid rich paint, respectively. Temperature and humidity sped up the emission process, giving a higher total amount of aldehydes. A higher amount of linoleic acid slowed down the emission process and gave higher total amounts of aldehydes. Artificial light and air exchange rate showed no significant effects on the emission process. (C) 2002 Elsevier Science B.V. All rights reserved.