Margaret (Peg) Seminario was the director of occupational safety and health for the AFL-CIO from 1990 until her retirement in 2019. She is a nationally recognized occupational safety and health leader and expert with extensive experience in safety and health policy, regulation, and legislation.  

She worked for the AFL-CIO since 1977, and led the federation’s efforts to seek improved safety and health protections for workers, participating in dozens of rule makings before the Occupational Safety and Health Administration and organizing broad-based campaigns on the right to know about chemical hazards and ergonomic protections. She was one of the leaders in labor’s efforts to enact the 9/11 Health and Compensation Act to provide health care and compensation to responders sick from exposures at the World Trade Center. Seminario was the AFL-CIO’s lead organizer of Workers Memorial Day, observed annually on April 28, to remember workers killed, injured and diseased on the job and to highlight the need for improved job safety protections.  

Seminario served on numerous federal agency and scientific advisory committees and participated in international safety and health work through the International Labor Organization, the Organization for Economic Cooperation and Development and international trade union organizations.  

She holds a Master of Science degree in industrial hygiene from the Harvard T.H. Chan School of Public Health and a Bachelor of Arts in biological sciences from Wellesley College.