The Michigan legislature created the modern Michigan Occupational Safety and Health Act, Public Act 154 of 1974, in order to better prevent workplace injuries, illnesses and fatalities in Michigan by: setting and enforcing occupational safety and health standards; promoting safety and health training and education; and working with partners to develop innovative programs to prevent workplace hazards. P.A. 154 went into effect for private sector employers on January 1, 1975 and for public sector employers on July 1, 1975.
The MIOSHA Act established the General Industry Safety Standards Commission, the Construction Safety Standards Commission, and the Occupational Health Commission. The commissions are responsible for developing standards in consultation with advisory committees whose members represent the major interests affected by the proposed standard. The standards are intended to protect the health and safety of Michigan's employees.
Among the most significant changes since MIOSHA's inception are
- Act 105 of 1991 amended Act 154 of 1974 and provided for the increase in the MIOSHA civil penalties to the level identical to the federal penalties
- the MIOSHA Act was amended again in 1986 by Public Act 80 - the Michigan Right to Know Law. This amendment included requirements for the communication of information regarding the safe handling of hazardous chemicals present in Michigan workplaces.
MIOSHA was administered by the Michigan Department of Public Health, Occupational Health Division and the Michigan Department of Labor, Bureau of Safety and Regulation until 1996 when Governor John Engler issued Executive Order 1996-1 which transferred occupational health responsibilities to the Bureau of Safety and Regulation.
In September 2003, Governor Jennifer M. Granholm signed Executive Order 2003-14 creating the Department of Labor and Economic Growth (DLEG). The department was created by renaming the Department of Consumer and Industry Services (CIS) and merging many Department of Career Development functions into the new department along with several other key programs from other departments.
Effective December 8, 2003, the MIOSHA program reorganized its operational structure by creating the Management & Technical Services Division and combining enforcement divisions. The General Industry Safety Division, Construction Safety Division and the Occupational Health Division became the General Industry Safety & Health Division (GISHD) and the Construction Safety and Health Division (CSHD). The MIOSHA Information Division became the Management Information Systems Section and the MIOSHA Standards Division became the MIOSHA Standards Section. Both are administered by MTSD. The Employee Discrimination Division became the Employee Discrimination Section and is administered by GISHD. The Asbestos program is administered by CSHD. In addition, the program name changed from the Bureau of Safety and Regulation to the Michigan Occupational Safety and Health Administration (MIOSHA).
On December 28, 2008, Governor Jennifer M. Granholm signed Executive Order 2008-20 creating the Department of Energy, Labor & Economic Growth (DELEG). The department was created by renaming the Department of Labor and Economic Growth (DLEG) and ensuring efficient administration and effectiveness of government.
Effective April 24, 2011, Governor Rick Snyder signed Executive Order 2011-4 creating the Department of Licensing & Regulatory Affairs (LARA). The department was created by renaming the Department of Energy, Labor & Economic Growth (DELEG) and reorganizing functions among state departments to ensure efficient administration. Included in this Executive Order, the Wage & Hour Division joined the Michigan Occupational Safety & Health Administration (MIOSHA).