Plants for planting can carry a wide variety of pests that are more likely to become established in the U.S. because they are already on a suitable host. In some cases, the plants themselves are the pest. To ensure U.S. import regulations provide adequate protection against the risk posed by plants for planting, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) established a regulated category called "Not Authorized Pending Pest Risk Analysis" (NAPPRA). NAPPRA allows APHIS to more fully protect U.S. agriculture from foreign pests while minimizing adverse economic and trade impacts. Under NAPPRA, plants for planting must undergo a pest risk analysis before APHIS will authorize the taxon for importation.
Before NAPPRA, APHIS' plants for planting regulations (also known as Q37) categorized imported plants as either prohibited (not allowed) or restricted (allowed under certain conditions). The regulations did not require a pest risk analysis prior to the importation of a new taxonomic group of plants. This differed from APHIS' fruits and vegetables regulations (Q56) where the importation of regulated articles is prohibited until APHIS completes a pest risk analysis.