Is it permissible for a man to wash a woman's outer garments?

There is no religious impediment for men to wash women's clothes, or for women to wash men's clothes, whether together or separately, and whether the washer is a professional or a volunteer. Owners of laundromats must be careful not to mix impure clothes with pure ones, so that all of them do not become impure. They must purify impure clothes first before mixing them with others.