Abstract
Film-forming agents (FFAs) are volatile organic compounds used in paints and are of global health concern. In this study, 174 paint samples manufactured by 14 different paint manufacturers and marketed in Lagos and Ibadan, Nigeria were purchased. Samples were solvent-extracted with acetonitrile and the FFAs present were identified and subsequently quantified using GC-MS and GC-FID, respectively. Biodegradation study of the most commonly used FFAs was also carried out. Ethylene glycol butyl ether (EGBE), diethylene glycol butyl ether (DEGBE), ethylene glycol butyl ether acetate (EGBEA) and ethylene glycol ethyl ether acetate (EGEEA) were present in the paint samples. The FFA levels in all studied paint samples ranged from 1,010-3,350 ppm of DEGBE, 1,000-1,860 ppm of EGBE, 1,120-3,870 ppm of EGBEA and 1,020-2,900 ppm of EGEEA. The levels of these FFAs were above the European Union (EU) permissible limits of 500 ppm for volatile organic compounds (VOCs) in paints. Therefore, water-based paints marketed in Nigeria contain high concentrations of these FFAs, which are of human health concern and hazardous to the environment. During the biodegradation of EGBEA, the stationary phase was observed at 20 ppm (cell growth rate equals cell death rate). This implies a possible bioaccumulation over time. Also, biodegradation of EGBEA fitted into a typical Monod kinetics model for substrate utilization.