Cave-ins are considered the most dangerous trench and excavation hazard.  Other potentially fatal hazards also exist in excavations, such as asphyxiation due to lack of oxygen in a confined space, inhalation of toxic fumes, drowning, falls, water accumulation, etc. The OSHA standards intend to protect workers in trenches and excavations. This course gives you a basic understanding of how to work safely in excavations and the skills and techniques required to work safely in excavations.