Good experimental practice (GEP)

The European and Mediterranean Plant Protection Organization (EPPO) published its first Standard on GEP in 1992 (EPPO Standard PP 1/181: “Conduct and reporting of efficacy evaluation trials, including good experimental practice”). Since then, this standard has been the basis for study design, conduct and reporting of regulatory efficacy trials in plant protection, i.e. trials that are to be used for registration purposes.

According to this standard, “the primary aim of Good Experimental Practice (GEP) is to ensure that high-quality trials are conducted. This ensures that results can be used by different registration authorities. GEP is concerned with the management of efficacy evaluation trials and with the conditions under which trials should be planned, conducted, assessed, recorded and interpreted so that their results should be comparable and reliable. GEP relates to various aspects: staff qualifications, use of suitable equipment and facilities, protocols, modes of operation, recording of results.

In practice, GEP requires consideration of the following:

  • The criteria to be respected by the organizations responsible for the trials
  • The modes of operation of these organizations
  • The internal procedures for verification of the use of GEP.”

Therefore, trials to be used in the plant protection product registration process in EU should be conducted at official or officially recognized GEP organizations and providing the respective GEP certificate in the respective study reports.

Trials at non GEP-certified organisations, e.g. academia or CROs outside the EU, should follow the rules of EPPO or other respective scientific standards, to allow for scientific justification for comparability and provide the possibility to use the trial data in EU product registration processes. In many cases non-GEP studies can be used in the regulatory process, if respective scientific justifications for comparability, relevance and validity can be provided, reducing cost for product performance and efficacy study programs.