Play-Doh is a non-toxic compoun similar in texture to bread dough that has been sold as a children's toy around the world for over half a century. Its exact makeup is a trade secret, but it is primarily a mixture of wheat flour, water, mineral oil (which provides the smooth texture), salt, a drying agent such as borax (which deters mold), an alum-based hardening agent, and colorings and perfume.