Autoclaving is a commonly used method for sterilizing medical instruments and laboratory equipment. The pressure inside an autoclave affects the temperature and, thus, the timing of the sterilization process. An autoclave uses steam under pressure to raise the temperature of the contents of the chamber, allowing it to reach the required sterilization temperature of 121°C or 134°C (Panta et al., 2019). At higher pressures, the boiling point of water is raised, so the temperature inside the autoclave can be increased to reach the sterilization temperature more quickly. The temperature inside an autoclave is influenced by the type and amount of load being sterilized, as well as the size and shape of the autoclave chamber. When the load is heavily packed, or the autoclave is overfilled, it can take longer for the steam to penetrate the load and reach the required temperature. Similarly, when the load is too small or spread out, the steam may escape too quickly, reducing the pressure inside the autoclave and making it more difficult to reach the sterilization temperature.
Moist heat and dry heat have different abilities to destroy microbes. Moist heat, as used in autoclaving, is more effective in killing microorganisms compared to dry heat, which uses hot air to sterilize items. Moist heat is more efficient in killing bacteria, viruses, and spores of fungi since the high temperature and pressure create an environment that is hostile to the survival of these pathogens. Dry heat is less effective at destroying microorganisms and takes longer to achieve sterilization than moist heat, but it is still useful for sterilizing heat-sensitive materials that cannot withstand the high temperatures and pressure used in autoclaving (Panta et al., 2019). Thus, moist heat is more effective in destroying microbes than dry heat, making it the preferred method for sterilizing medical instruments and laboratory equipment.
Reference
Panta, G., Richardson, A. K., & Shaw, I. C. (2019). Effectiveness of autoclaving in sterilizing reusable medical devices in healthcare facilities. The Journal of Infection in Developing Countries, 13(10), 858-864. Web.