An ERD (Entity Relationship Diagram) is a graphical representation of the data in rest within a system (e.g. a business, an organization, an application) that is subject to analysis.
The U.S. EPA established the Reference Dose (RfD) Work Group to address these concerns. In preparing this report, the RfD Work Group has drawn on traditional report on risk assessment (NRC, 1983), to more fully articulate the use of noncancer, nonmutagenic experimental data in reaching regulatory decisions about the significance of exposures to chemicals.
The RfD is useful as a reference point from which to gauge the potential effects of the chemical at other doses. Usually, doses less than the RfD are not likely to be associated with adverse health risks, and are therefore less likely to be of regulatory concern.