Which organization sets safety standards for radon exposure in residential homes?

The correct answer is the Environmental Protection Agency (EPA) because this organization is specifically tasked with overseeing environmental protection laws and regulations, which include those related to indoor air quality and radon exposure. The EPA has established guidelines and recommendations for radon levels in homes and public buildings, aiming to protect public health and minimize the risks associated with radon exposure, a known carcinogen. Their involvement includes providing resources for safely assessing and mitigating radon levels, as well as educating the public on the risks associated with radon in residential settings.

Other organizations, while also important in public health and safety, do not have the same direct focus on residential radon contamination. For example, OSHA primarily deals with workplace safety regulations, NIOSH is involved in occupational safety research and recommendations rather than residential standards, and the CDC focuses on broader public health concerns but does not set specific safety standards for radon in homes.