Hazard characterisation type extrapolation

Hazard doses, or points of departure can be of various types. E.g., BMDs, NOAELs, or LOAELs. When computing hazard characterisations, the type in which the hazard characterisations are expressed (i.e., the hazard characterisation expression type) should be specified explicitly. When points of departure from types different from the expression type are provided, these should be translated to the specified expression level. In the current implementation, the simple conversion factors shown in Table 170 are used, roughly based on the WHO guidance document on evaluating and expressing uncertainty in hazard characterization, see WHO (2018).

Table 170 Conversion factors for hazard characterisation types.

From	To	Conversion factor
BMD	NOAEL	1/3
BMD	LOAEL	1
NOAEL	BMD	3
NOAEL	LOAEL	1/3
LOAEL	BMD	1
LOAEL	NOAEL	1/3