The NAS Committee defines a NOEL as “the highest dose at which there are no statistically or biologically significant increases in the frequency or severity of any effect between the exposed populations and its appropriate control.” on page 168 of the report, “Health Implications of Perchlorate Ingestion.” The NAS committee states that a dose of 0.007 milligrams per kilogram of body weight per day is the NOEL. Using standard default EPA conversion practices, this is equivalent to 245 ppb in drinking water.
