The Occupational Safety and Health Act (OSHA) is the primary regulation that governs occupational safety and health in the U.S. OSHA has a standard that governs entry into confined spaces (Standard 1910.146, see below for a direct link) but production agriculture has been specifically exempted from this standard. One may think there is no reason for a farmer to be concerned about their confined space manure storage and the OSHA regulation, but this is not completely accurate. If a farm operator employs 11 or more non-family workers and is inspected for any reason, OSHA can use its “general duty clause” to cite the employer for violation of easily recognized best safety practices. Section 5 of the OSHA standard identifies specific duties for employers and employees The OSHA general duty clause says, in part, that each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees. See below for a direct link to the complete Duties section.
The hazards of manure storages are well-documented. Allowing a hired worker to enter a manure pit without an adequate supply of contaminant-free air, without a safety harness with a lifeline attached to a rescue lifting device, or without using atmospheric testing devices, violates best safety practices for entering manure pits.
Several states have their own state Occupational Safety and Health regulation. One provision in the federal OSHA Act is that if a state adopts a state OSHA plan it has to be at as strict or stricter than the federal regulation. This means that in states with their own OSHA plan, farm operations may not have the same exemptions from standards or enforcement of standards as exists in states where only federal OSHA is in effect. Farmers should know if their state has a state OSHA plan and how those regulations may differ from federal OSHA regulations.
To see if your state has a state approved OSHA plan, see http://www.osha.gov/dcsp/osp/index.html.