|This web page contains a compilation of documentation on the science and applications of non-testing methods, including (Quantitative) Structure-Activity Relationships and chemical grouping methods. More information is available from the links below.|
|Among the different methods that can be used in the hazard assessment of chemicals are the so-called non-testing methods, which comprise (Q)SAR models and other, less formalised, approaches based on the grouping of chemicals (read-across and chemical category formation). To address financial and animal welfare concerns, the REACH legislation explicitly expresses the need to use non-testing methods to reduce the extent of experimental testing.
Qualitative and Quantitative Structure-Activity Relationships - (Q)SARs
A structure-activity relationship (SAR) is a qualitative relationship that relates a (sub)structure to the presence or absence of a property or activity of interest. The substructure may consist of adjacently bonded atoms, or an arrangement of non-bonded atoms that are collectively associated with the property or activity.
A quantitative structure-activity relationship (QSAR) is a mathematical model (often a statistical correlation) relating one or more quantitative parameters derived from chemical structure to a property or activity of interest. QSARs are quantitative models yielding a continuous or categorical result.
Chemical categories and read-across
Threshold of Toxicological Concern
OECD Principles for the Validation of (Q)SARs