Machinery

Question

Sorry for not being clear. Let me try to clarify my question. Ofcourse I go to a supermarket and fly on planes, I'm not saying that you can't enter a store which houses chametz, However to buy a coffee in a store where the people making the coffee are also handling the donuts and other chametz objects I can see as a problem. ie; the individual making your coffee just handled the donuts and there is some (crumbs) chametz on his hands, which fall into your coffee. Isn't even a mashehu too much on pesach? Please explain. Thanx