Which organization is responsible for ensuring safe and healthful working conditions in the U.S.?

The Occupational Safety and Health Administration (OSHA) is the organization responsible for ensuring safe and healthful working conditions in the U.S. Established in 1970, OSHA's primary mission is to promote workplace safety and health by setting and enforcing standards, providing training, outreach, and education, and encouraging continual improvement in workplace safety protocols.

OSHA develops regulations that employers must follow to protect their workers from various workplace hazards and conducts inspections to ensure compliance. By creating a regulatory framework and offering guidance on safe working practices, OSHA plays a crucial role in preventing workplace injuries, illnesses, and fatalities across various industries, including construction.

Other organizations mentioned, while they have important roles in specific areas of environmental protection or occupational research, do not have the same regulatory authority in relation to workplace safety and health as OSHA does. The Environmental Protection Agency focuses mainly on environmental protection, the National Institute for Occupational Safety and Health conducts research and provides recommendations related to health and safety but lacks enforcement power, and the American National Standards Institute oversees the development of consensus standards but does not enforce regulations. Thus, OSHA stands out as the primary authority on workplace safety in the U.S.