Hi, I am staying with family and they do not toivel. Is it ok to consume food in which there was only the container (e.g., box of cookies, bottle of juice) and a paper towel between the actual food and the cutting board, etc.? (which actually may be plastic)?
Here are some halachos regarding tevilas keilem (immersing vessels) that will help clarify things for you. The only vessels that nee to e immersed before using are metal or glass utensils that come in direct contact with the food. Therefore, a box of cookies, unless it is a metal box does not need tevila. The same would apply to a plastic cutting board, or using plastic plates or disposable cutlery.
Another halacha. In retrospect, if food was cooked in a vessel that was not properly toveled, although what the owner did was improper, the food however is not for bidden to eat. Therefore, even though the food was cooked in metal pots that weren’t toveled, the food is still permitted to eat. Therefore, the only thing you have to be concerned with, is that you eat the food with plasticware.
Regarding your question. If the food was in a glass or metal container, which needs tevila, a paper towel will not permit the food to be placed in the container. The reason is because a paper towel is only a temporary cover, and insignificant in reference to the container, therefore the food is still considered in the metal or glass dish.
Yora Deah 120-1 Rema ibid 120-16, Minchas Shlomo 2-66(5).