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An autoclave is a pressure chamber used to carry out industrial and scientific processes requiring elevated temperature and pressure different from ambient air pressure. Autoclaves are used in medical applications to perform sterilization and in the chemical industry to cure coatings and vulcanize rubber and for hydrothermal synthesis. Industrial autoclaves are used in industrial applications, especially regarding composites.Sterilization autoclaves are widely used in microbiology, medicine, podiatry, tattooing, body piercing, veterinary medicine, mycology, funerary practice, dentistry, and prosthetics fabrication. They vary in size and function depending on the media to be sterilized and are sometimes called retort in the chemical and food industries.It is very important to ensure that all of the trapped air is removed from the autoclave before activation, as trapped air is a very poor medium for achieving sterility. Steam at 134 °C can achieve a desired level of sterility in three minutes, in contrast to hot air at 160 °C, which can take two hours to achieve the same sterility.A medical autoclave is a device that uses steam to sterilize equipment and other objects. This means that all bacteria, viruses, fungi, and spores are inactivated. However, prions, such as those associated with Creutzfeldt–Jakob disease, and some toxins released by certain bacteria, such as Cereulide, may not be destroyed by autoclaving at the typical 134 °C for three minutes or 121 °C for 15 minutes. Although a wide range of archaea species, including Geogemma barosii, can survive and even reproduce at temperatures above 121 °C, none of them are known to be infectious or otherwise pose a health risk to humans; in fact, their biochemistry is so different from our own and their multiplication rate is so slow that microbiologists need not worry about them.Most medical-grade autoclaves are inappropriate for research tasks. General-use non-medical (often called 'research-grade') autoclaves are increasingly used in a wide range of education, research, and industrial settings (including biomedical research) where efficiency, ease-of-use, and flexibility are at a premium. Research-grade autoclaves may be configured for 'pass-through' operation. This makes it possible to maintain absolute isolation between 'clean' and potentially contaminated work areas. Pass-through research autoclaves are especially important in BSL-3 or BSL-4 facilities.There are physical, chemical, and biological indicators that can be used to ensure that an autoclave reaches the correct temperature for the correct amount of time. If a non-treated or improperly treated item can be confused for a treated item, then there is the risk that they will become mixed up, which, in some areas such as surgery, is critical.Stovetop autoclaves, also known as pressure cookers—the simplest of autoclavesThe machine on the right is an autoclave used for processing substantial quantities of laboratory equipment prior to reuse, and infectious material prior to disposal. (The machines on the left and in the middle are washing machines.)Horizontal high-capacity autoclave with cylindrical chamberIllustration of a cylindrical-chamber pass-through autoclave