Contaminant
Part of speech: noun
Definition: That which contaminates; an impurity; foreign matter.
Contamination
Part of speech: noun
Definition: The act or process of contaminating; pollution; defilement; taint; also, that which contaminates.A grammatical blend, portmanteau.The process of making a material or surface unclean or unsuited for its intended purpose, usually by the addition or attachment of undesirable foreign substances.
Example sentence: I think the biggest thing is clean as you go. Wash all your knives, cutting boards, dishes, when you are done cooking, not look at a sink full of dishes after you are done. Cleaning as you go helps keep away cross contamination and you avoid having food borne bacteria.