In April, the Agency for Toxic Substances and Disease Registry solicited nominations of substances to evaluate for the development of a new set of toxicological profiles. The agency was considering nominations from its Substance Priority List, which comprises chemicals that are candidates to become the subject of toxicological profiles prepared by ATSDR. The list includes substances that are most commonly found at facilities on EPA’s National Priorities List of “Superfund” sites that have had known or threatened releases of hazardous substances, pollutants, or contaminants. ATSDR’s Substance Priority List prioritizes substances that ATSDR and EPA have determined pose the “most significant potential threat to human health due to their known or suspected toxicity and potential for human exposure” at Superfund sites. The list is revised and published every two years. Substances at the top of ATSDR’S 2017 list include arsenic, lead, mercury, vinyl chloride, and polychlorinated biphenyls. ATSDR will evaluate the data and information associated with the nominated substances and will determine the final list of substances for toxicological profile development.  ATSDR toxicological profiles characterize information about the toxicology and adverse health effects of hazardous substances. Each peer-reviewed profile identifies and reviews the key literature that describes a substance's toxicological properties. A full list of toxic substances with published profiles is available on the agency’s website. To view ATSDR’s Substance Priority List, visit the agency's website. EPA’s National Priorities List of Superfund sites is available on the EPA website. For more information about ATSDR’s plans to develop new toxicological profiles, view the Federal Register notice.