The donor must not be asked to remove any article of clothing other than those previously mentioned. Additionally, the donor must not be asked to remove clothing in order to wear an examination gown unless undergoing a physical examination authorized by the Department of Transportation. Boots do not have to be removed unless the collector is suspicious that they contain something in them that could be used to adulterate or dilute the specimen or be used as a substitute.

If the donor refuses to remove a head covering because of religious reasons, the collector may exempt the donor from doing so unless the collector has an observable indicator that the donor is trying to hide something inside the head covering.