The phrase "sanitary purposes" refers to using something in a way that promotes cleanliness, hygiene, and prevents the spread of germs or diseases. Full definition
It has a wide stopper so you can't inadvertently insert it too far, and the tips are replaceable for sanitary purposes. (businessinsider.com)
I knew it was the right choice because of style / color, and as you pointed out — sanitary purposes which is the same reason white towels & bedding are important to guests. (shadesofblueinteriors.com)
He was given a shovel for sanitary purposes, a girdle, and a white garment which he wore at meetings of the group. (religion-online.org)