What is the Part Per Billion (ppb) level in drinking water that equates to the NOEL as defined by the NAS Committee?

by perchlorate | Sep 1, 2022 | Science

EPA uses standard default conversion factors for body weight (70 kilograms) and tap water consumption (2 liters per day) to translate RfDs to drinking water equivalents in ppb. For most people in a population, these assumptions are conservative as most people do not...

What level is safe for pregnant women? What level is safe for children? Why not be extra cautious?

by perchlorate | Sep 1, 2022 | Perchlorate and Health

To derive the recommended reference dose – the maximum amount of a substance in drinking water that the U.S. Environmental Protection Agency (U.S. EPA) considers “safe” if consumed every day for a lifetime of exposure – the National Academies...

Who decides whether and how the additional studies should be conducted?

by perchlorate | Sep 1, 2022 | Science

The NAS Committee made several recommendations for future research, noting that sufficient data now exists to move forward with the regulatory process. Since the NAS report, multiple studies have filled the few data gaps identified by NAS and have confirmed the NAS...

What body weight should be used to calculate a safe drinking water concentration using the NAS Committee’s recommended RfD?

by perchlorate | Sep 1, 2022 | Science

By definition, an RfD assumes exposure over a lifetime and takes into account special considerations of sensitive populations such as pregnant women, children, infants and fetuses. Read the U.S. EPA’s definition of a reference dose on their website » The NAS Committee...

What is a simple definition of “point of departure?”

by perchlorate | Sep 1, 2022 | Science

In risk assessment, the “point of departure” is the dose selected as the starting point to which uncertainty or safety factors are applied to derive a “safe” dose. See the EPA’s definition of “point of departure” on their website »...