In the United States there are two agencies responsible for workplace safety: the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). These two agencies are part of the US Department of Labor and are under the administration of the Secretary of Labor. Generally speaking, OSHA is responsible for safety regulations covering general industry and construction while MSHA is responsible for safety covering mining and other mineral based industries. The actual distinction between the jurisdictions of the two organizations are far more complex than my simple definition. If you search for the phrase "OSHA vs. MSHA jurisdiction" you will find a long list of articles about the sometimes not so clear jurisdictional boundaries.
While the two organizations are tasked with similar responsibilities in their respective jurisdictions, they have separate rules and regulations and enforcement procedures. At times these can be remarkably similar and at other times remarkably different. In the gray areas where the lines between the jurisdictions are blurred, operators can be in compliance with the rules of one organization and find itself out of compliance with the rules of the other organization. It is very important that the operator of any facility understand which set of rules govern their operation.
Please remember that I am not an attorney or expert of the law. I am just an engineer that has worked on a fair number of production facilities (both OSHA and MSHA jurisdiction) and interacted with Environmental, Health and Safety (EH&S) personnel whose job is to make sure that the workers are safe AND the applicable regulations are being followed. The things in this blog are not legal or even formal engineering recommendations. If you run into a situation about OSHA/MSHA compliance or procedure, go to a pro. Based on what I have read, you will need a professional who understands the process, the language, and the regulations. If you try to go it alone you risk scuttling your case due to procedural errors even if you have a rock solid, no way to lose case.