Excerpt: Occupational exposure to secondhand smoke (SHS)—also known as environmental tobacco smoke—still occurs. According to the U.S. Surgeon General, “Approximately 30% of indoor workers in the U.S. are not covered by smoke-free workplace policies” (DHHS, 2006). Occupational safety professionals and agencies have investigated SHS exposures to workers in the hospitality industries (e.g., restaurants, lounges, casinos), as well as in offices or environments where smoking was allowed (Trout, Decker, Mueller, et al., 1998; Repace & Homer, 2005; Repace, Hughes & Benowitz, 2006b). For example, professionals investigating indoor air quality (IAQ) complaints have long known that one must rule out the possible contribution of smoking to the environmental and health impacts being evaluated (Hodgson, 1989). Given the potential magnitude and concern for SHS in occupational environments (DHHS, 2006; CDC, 2007; Goodwin, 2007; WHO, 2007), SH&E professionals must continue to characterize SHS exposure levels in the workplace.