This guide provides basic information about mold, mold sources, and building-related illnesses. Brief discussions are included on building design considerations for healthy indoor air, as well as building evaluation and sampling for mold. The purpose of this guide is to help owners, managers, and occupants understand and prevent building-related illnesses associated with mold problems in offices and other indoor workplaces. U.S. Department of Labor Occupational Safety and Health Administration OSHA 3304-04N 2006.