21 CFR § 112.33
What measures must I take to prevent visitors from contaminating covered produce and food contact surfaces with microorganisms of public health significance?
June 25, 2020
(a) You must make visitors aware of policies and procedures to protect covered produce and food contact surfaces from contamination by people and take all steps reasonably necessary to ensure that visitors comply with such policies and procedures.
(b) You must make toilet and hand-washing facilities accessible to visitors.