A sterilization tray is a receptacle that medical and surgical instruments are placed into before being loaded into an autoclave for sterilization. An autoclave is a device that uses highly pressurized steam to rid instruments of any microbial organisms prior to medical procedures or surgery. Typically, there are a number of sterilization trays that can fit into the autoclave at any given time. The trays can be manufactured from aluminum, stainless steel, durable plastics, and composite, or hybrid materials. This method combines the strongest aspects of both plastic and metal.
Aluminum sterilization trays are commonly used in doctor's offices, but plain aluminum tends to oxidize easily when inside an autoclave, so most aluminum sterilization trays are anodized. Anodizing is a process of coating the aluminum sterilization tray with a protective oxide layer. This is due to its durability and light weight. Stainless steel trays are more expensive and somewhat heavier. Plastic sterilization trays are fairly durable and very light.
The instrument sterilization process seeks to eliminate all microbes. This can be difficult and testing is done to determine if the most powerful and resistant microbes have been killed. If they have expired, then the reasoning goes that the weaker microbes will have as well. Bacterial spores are the most resistant and these are used as a barometer of the sterilization process’ effectiveness. This process is referred to as biologic monitoring.
Once the surgical instruments have been stacked in the sterilization tray and placed in the autoclave, they are typically subjected to high pressure steam for anywhere up to 20 minutes. The size of the load and trays will somewhat determine autoclave time as well. The sterilization tray and instruments are steamed at a temperature of around 250° Fahrenheit (120° Celsius). There are trays that are designed for what is known as cold sterilization, but this not recommended because instruments immersed in any type of liquid for more than twenty minutes may sustain damage. Certain solutions are known to loosen the tungsten carbide in some instruments.
Once the sterilization tray and instruments have been sterilized they are usually monitored and checked. Sometimes debris can remain on the instruments and bacterial spores may still be present. If spores are detected, the entire process is repeated. Some of the methods used to monitor for the presence of spores include spore strips enclosed in a protective casing, chemical monitoring, and mechanical monitoring. This can entail keeping a close eye on the maintenance of the machine itself and servicing it if any unusual sounds arise.