While OSHA generally governs safety rules for the workplace there is one industry not subject to OSHA safety rules.  That is mining.  Mining safety is governed by the Federal Agency Mine Safety and Health Administration.  MSHA functions much the same way OSHA does but there are several notable exceptions.

First, MSHA is required by law to visit mines two times each year (Surface, Metal/Nonmetal) and Coal mines/underground mines 4 times each year.  That is 100% inspection rate for MSHA.  OSHA inspection rates are much much lower.

Second, MSHA safety laws are enforced using the strict liability standard, while OSHA standard for enforcement is a lesser standard.

Third, it is possible to discuss and limit the scope and area of OSHA inspection.  MSHA has no such restrictions.