Who is responsible for ensuring safe use of technology?

The U.S. congress passes laws that authorize EPA and other federal agencies, to protect public health.The EPA has issued many laws that limit the release of different nuclides to the environment, as well how different companies use and access radium. While this only in the United States.
The makers, US Radium knew the safety risks involved and should have made the manufacturers and workers aware rather than lying and covering it up.