The Scientific Panel on Plant Protection Products and their Residues (PPR Panel) of EFSA was asked to make aninventory of protected crop systems (e.g. greenhouses and cultivations grown under cover) and emissions fromthese systems to relevant environmental compartments, and to provide guidance on the importance of emissionroutes including the circumstances under which they are relevant. This opinion identifies greenhouses andwalk-in tunnels having priority for scenario development. For these covered crop systems, the PPR Panelrecommends the development of tiered risk assessment procedures. Further investigation is necessary to find outwhether risk assessment for open field may be used as the first tier in these procedures. The opinion furthermoreaddresses elements that should be considered in deriving the risk assessment scenarios, for both soil-bound andsoil-less cultivations.