Concerns were raised again when the bovine spongiform encephalopathy (BSE) epidemic, commonly known as "mad cow disease", occurred in the United Kingdom in 1986. Since bits of the spinal cord (the part most likely to be carrying the BSE prion) often got mixed in with the rest of the meat, products using mechanically separated meat taken from the carcasses of bovines were at higher risk for transmitting BSE to humans. As a result, in 1989, the United Kingdom tightened restrictions to help ensure pieces of the spinal cord would not be present in mechanically separated meat taken from bovines. In the mid-1990s, the UK government banned MRM from cattle backbone, in 1998 MRM from any ruminant backbone and in August 2001 from any ruminant bone. In 2001, the government prohibited the sale of MRM beef for human consumption to prevent the spread of bovine spongiform encephalopathy.