Relative potency factors calculation

Relative potency factors (RPF s) describe the potency of substances with respect to a defined effect, relative to the potency of a chosen index or reference substance. RPFs are provided as data or computed from hazard characterisations. The RPF for substance \(i\) is defined by the ratio of hazard characterisation value (POD) for the index substance (\(\mathtt{ref}\)) and the hazard characterisation value for substance \(i\). That is,

\[\mathtt{RPF}_i = \mathtt{POD}_{\mathtt{ref}} / \mathtt{POD}_i .\]

When hazard characterisations are resampled in the uncertainty runs, RPFs are recomputed based on the bootstrapped hazard characterisations. In this way, RPF uncertainty is included in the uncertainty analysis.