Disinfection inactivates most microbes on the surface of a fomite by using antimicrobial chemicals or heat. Some microbes remain, so the disinfected item is not sterile. Disinfectants should be fast acting, stable, easy to prepare, and inexpensive. An example of a natural disinfectant is vinegar; its acidity kills most microbes. Chemical disinfectants, such as chlorine bleach, are used to clean nonliving surfaces such as clinical surfaces. Disinfected surfaces are not considered sterile because endospores can survive even when all the vegetative cells have been killed.