Detergents and detergency.
A simple definition of a "clean" surface is one which is "free from any residual film or soil which is visible or can be felt by touch", ie it should not contaminate food or other consumable items with odour, microbial spoilage or chemical residue.
D003902:Detergents / Q000592:standards*; D005069:Evaluation Studies as Topic; D006797:Housekeeping, Hospital; D013501:Surface-Active Agents / Q000592:standards*