The Health Advisory (HA) Program, sponsored by the Office of Water (OW), provides information on the environmental properties, health effects, analytical methodology, and treatment technology for regulated and unregulated drinking water contaminants. HAs establish non-regulatory concentrations of drinking water contaminants at which adverse health effects are not anticipated to occur over specific exposure durations (one day, ten days, a subchronic period, several years, and a lifetime). For perchlorate, EPA is establishing an interim health advisory level for subchronic exposure. HAs serve as informal technical guidance to assist Federal, State and local officials, and managers of public or community water systems in protecting public health when emergency spills or contamination situations occur. They are not legally enforceable Federal standards and are subject to change as new information becomes available.

"December 2008." "EPA 822-R-08-025." Includes bibliographical references.

In January 2009, EPA issued an interim health advisory to assist state and local officials in addressing local contamination of perchlorate in drinking water. The interim health advisory level of 15 micrograms per liter, or parts per billion (ppb), is based on the reference dose recommended by the National Research Council (NRC) of the National Academy of Sciences (NAS). The Agency is also seeking advice from the NAS before making a final regulatory determination on whether to issue a national regulation for perchlorate in drinking water.