Technically peaking, a State or city in the U.S. Could still make it illegal, as the separation of religion and state only applies to the federal government, and only applies if some religious group is being oppressed by a policy. XD

Regardless, the reason for all of the religious laws about that (I'm assuming we're talking Leviticus because it's what the three major monotheistic religions use.) had only to do with disease, in a time when there was no hand sanitizer, and not even a presentable sink to wash in. Spreading germs was easy, especially with biological material involved.