National legislation and regulations are fundamental
The legislation concerning the management of risks associated with the import of P4P and the associated dispersal of pests and diseases is, in most countries, based on international treaties and conventions (MacLeod et al., 2010), in particular the International Plant Protection Convention (IPPC; FAO, 1997) and the WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement; WTO, 1995). The IPPC stipulates the use of phytosanitary certificates and the right of countries to regulate the import of certain plant YM-155 to avoid entry of pests, to inspect or quarantine specific consignments and to define which pest species are not allowed to enter the country. The SPS Agreement stipulates that countries have the right to decide their own level of acceptable risk, and to apply phytosanitary measures as required to protect plant life or health, as long as these do not discriminate against certain countries or foreign commodities and have the minimal necessary impact on trade. Moreover, any limits on trade set under the SPS Agreement have to be based on science or international standards, such as the International Standards on Phytosanitary Measures (ISPMs) set by the IPPC (except for provisional measures).