What is the name of the Govt Dept responsible for the Occupational Health and Safety of all workers?

There is no single government department that is responsible for the occupational safety and health ofall workers in the US. The Us Department of labor has the Occupational Safety an Health Administration, which is responsible for establishing and enforcing standards of workplace health and safety, but has direct authority in only about half the states, and a small number of Federal Departments. And in those states directly covered by OSHA, state and municipal employees are not covered by OSHA except in NY, NJ, IL, and the Commonwealth of Puerto Rico. Some 21 States have their own workplace safety programs that cover all but certain Federal employees. Most federal Departments manage their own health and safety programs, modeled on Federal OSHA.