HERO is an evergreen database; this means that new studies are continuously added so scientists can keep abreast of current research. Imported references are systematically sorted, classified and made available for search and citation.

HERO includes more than two million scientific references and associated data from the peer-reviewed literature used by EPA to develop reports that support critical agency decisionmaking for chemical regulation.

HERO is part of the open government directive to conduct business with transparency, participation, and collaboration. Every American has the right to know the data behind EPA's regulatory process. With HERO, the public can access the scientific information and data that inform Agency decisions.

Scientific integrity ensures the objectivity, clarity, reproducibility, and utility of EPA research. Only in such a rigorous climate can the best decisions can be made.