Initially, the USDA list included only countries and other regions in which BSE was known to exist, such as the United Kingdom, France, Switzerland, and the Republic of Ireland.

In 1998, the USDA expanded the list to include countries and other regions in which BSE had not been documented but in which import requirements were less restrictive than requirements that would be acceptable for import into the United States or in which there was inadequate BSE surveillance.

Thus, all European countries, even those that have had no reported cases of BSE, are currently on the USDA list, which is published in the Code of Federal Regulations, title 9, part 94 (9C.F.R., part 94).