At least one mop sink or one curbed cleaning facility equipped with a floor drain must be provided and conveniently located for the cleaning of mops or similar wet-floor cleaning tools and for the disposal of mop water and similar liquid waste. Lavatories or sinks normally used for preparing food or washing utensils or equipment may not be used for this purpose.
Nev. Admin. Code § 446.427
NRS 439.200, 446.940