Many foods produced on an industrial scale include raw ingredients mixed together in enormous stainless steel machines that can be difficult to clean. With repeated use, equipment surfaces get minute scratches and grooves, providing bacteria and biofilms the perfect place to hide. While surface scratches may appear small to the naked eye, they are like a canyon to bacteria, which are only a few micrometers in size. Surface-trapped food residue and bacteria then increase the risk of contamination from microorganisms such as Salmonella, Listeria and E. coli.