Candidates for Substitution (CfS) and comparative assessment
Plant protection products containing existing active substance(s) listed as Candidate for Substitution are subject to a comparative assessment before a possible product authorisation or re-authorisation can be approved. Candidate for Substitution substances are active substances with unfavourable properties which shall be substituted by other substances. This assessment is conducted by each concerned Member State (i.e. not the zonal Rapporteur Member State) at the use level where an (re-)authorisation of the plant protection product has been requested.
The concept of the comparative assessment is described in detail in SANCO/11507/2013, as well as EPPO standard PP 1/271 and includes, with regards to efficacy, the effectiveness, the risk of developing resistance, and the availability of chemical alternatives with several mode of actions, their effects on minor uses and the availability of other products for minor uses on the market. The availability of alternative products on the market differs per Member State, which is why the comparative assessment has to be conducted on a Member State level.
A special situation occurs when a plant protection product contains a new active substance, which is a candidate for substitution. In this case, a product authorisation might be granted without a comparative assessment to gain the necessary experience to conduct such an assessment on a later stage. This special authorisation will not exceed a period of five years.