Indoor ambient monitoring revealed that the high levels of Volatile Organic Compounds are associated with places where solvents are frequently used, either for paint dilution or cleaning mechanic parts (electromechanical repair and car painting center), or as solvents of the inks and/or toner used in printing works (photocopy centers), and also by its use in chemical process (chloroform for laboratories). However, the unusual high levels of hexane and BTEX associated with sewing workrooms may be explained by contamination coming from outdoor air, due to the proximity to the electromechanical repair and car painting center.