Q. I'd like to ask whether laundry detergent needs a hechsher. There seem to be a lot of major brands that don't have one. Also, is there a difference if one is laundering dish towels?
A. According to COR and other Kashrus authorities, there is no need for certification for laundry detergents, and they could be used for dish towels or washing dishes themselves.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit"a