APHIS had previously reviewed and also deregulated these traits in another variety of Simplot potato, which they refer to as Innate W8 Russet Burbank potato (W8 potato), according to the USDA.

When APHIS reviewed Simplot's extension request for the Z6 potato variety, it prepared a Plant Pest Risk Similarity Assessment (PPRSA) and preliminary determination of nonregulated status. It concluded that Z6 potatoes are not more likely to pose a plant pest risk than the previously deregulated W8 potatoes. Based on its similarity assessment, APHIS reached a Record of Categorical Exclusion Determination, which is a category of actions that do not individually or cumulatively have a significant effect on the human environment and have no such effect on procedures adopted by a federal agency in implementation of these regulations and for which, therefore, neither an environmental assessment nor an environmental impact statement is required. 

The PPRSA and preliminary determination was made available for a 30-day public review and comment period by APHIS on June 25, 2020. After reading the public comments, APHIS determined the Z6 potato is unlikely to post a plant pest risk and is extending deregulation to the Z6 potato line.