There are many hazards associated with confined spaces. Confined spaces are classified on the ease of entry and exit. In the text it states “The key indicator in this determination process often is the ability to quickly exit an area. OSHA places considerable importance on the ability of an employee to quickly and safely exit all areas where they work. Any limitations on this action are reason for OSHA to examine and regulate. It is safest to define questionable spaces as confined spaces” (Gantt, 2012, p 322). One of the most common causes of death in confined space operations is atmospheric hazards. Other causes include physical hazards such as Engulfment, entrapment, and high noise levels. These hazards have more to do with the confined space than atmospheric hazards. As stated in the text “Common confined spaces include storage tanks, storage and process vessels, silos, storage bins, hoppers, vaults, trenches, and pits” (Gantt, 2012, p 321). The group most susceptible to encountering these hazards are construction workers, welders, and laborers. These workers often work in confined areas for extended periods of time.