Q. A dishwasher that is in a rental unit and the inner walls are plastic, can it be made kasher and how?

A. Poiskim disagree whether a dishwasher made of synthetic materials such as plastic can be made kosher or not. Some suggest that since there is no masoires or established tradition on these new materials, we should be stringent and not permit koshering, Igrois Moshe (O.H. 2: 92, E.H.4: 7) opines that we should treat them as uncertain allowing leniency when the plastic utensil has not been used for twenty four hours.

Many Poiskim rule that since the Torah excludes solely earthenware utensils from the koshering process, any new discovered materials are included and can be made kosher (Chelkas Yaakov Y.D. 2: 45, Minchas Yitzchok 3: 67, Chayei Halevy 4: 6, Tzitz Eliezer 4: 6, et al.).

Horav Shloimo Miller’s Shlit”a opinion is that the dishwasher should be cleaned thoroughly, dismantling all parts that are reachable, scraping all nooks and crannies and scuffing in between the laminates, while using the strongest cleansing agents available. After twenty-four hours it should undergo three complete washing cycles, using the hottest water that the plumbing system provides, if the unit does not heat its own water.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a