1. Introduction
Manufacturers in developing countries have widely used solvents as raw material in different productions, such as plastic, coating, paint, and glue. Although nowadays water-based paints are preferred, rather than solvent-based paints, solvents are still used in the manufacture of specialty paints. In Thailand, xylene and toluene are used as major components in combination with other solvents in the paint production process. These toxic aromatic hydrocarbons may be dispersed during the production process and affect the health of exposed factory workers.