v What Type of Water Should be Used with a Laboratory Autoclave?

Last Updated on June 4, 2021

When using an autoclave the question that everyone wants to have answered is what type of water should be used with an autoclave. This depends on the type of autoclave that one uses. With certain types of autoclaves that are hooked into house water or steam, there isn’t much of a choice. However, one has the choice and should make the proper choice when using a top-loading autoclave.

A very convenient type of autoclave is the top-loading autoclave. Due to their independence from water line plumbing or “house steam” connections, autoclave installation is easy and less space is taken for sterilization, leaving more space for other equipment.

But without an outside source of water or steam, how do autoclaves produce saturated steam and proper conditions in which to sterilize media?

The answer is the presence of a powerful heating element in the base of the SX-Series Autoclave’s main chamber. Water is simply added into the top-loading lid to submerge the heating element in water. This step followed by insertion of the power plug into an appropriate electrical outlet completes the entire easy installation process.

The following is information about water for autoclaving. Including how water sensors work, tips about the proper type of water to use in autoclave sterilization and the reasons behind these methods.

Water Level Sensor. Safety is a high priority for all TOMY products. A water level sensor is installed in each system to ensure the heating element is submerged. This sensor detects the ionic content of the water in the system and will not permit the autoclave to operate if the water level is too low or no ions are detected. This makes pure DI water a bad choice to use because the sensor will not be activated and the autoclave will not run.

Mineral Buildup as a Problem. The main concern about the type of water to use in autoclaves is avoidance of mineral buildup. That will affect your autoclave and its parts negatively if not checked. Though tap water has much greater ion content than pure DI water and is important in activating the water level sensor, its advantage is also its main drawback. Tap water’s high mineral content will cause a lime scale buildup within the autoclave sterilizing chamber which can be very difficult to remove or clean. This phenomenon happens in varying degrees depending on location; in some areas the tap water is harder than other areas. For instance, Southern California tap water is several times harder than tap water from the Midwest or Northeast of the United States and lime scale buildup will present itself much faster.

DI Water to Limit Mineral Buildup, Extend Autoclave Life. A balance of DI water and tap water is recommended for the reasons stated above. This will ensure safe operation of the SX-Series Autoclaves and ease clean up of the sterilizing chamber. When setting up your autoclave, add 3-3.5 Liters of DI water to the chamber to cover the heating element and base plate by at least 5 cm. Then add ion-rich tap water (50 mL for the SX-500 and 100 mL for the SX-700) to make sure the sensor can detect the water level while keeping lime scale buildup to a minimum.

In Summary: Water is Key. Following these tips when adding water to your autoclave will ensure longevity of the systems and safety for you and your lab members for years to come. Please contact us with any further inquiries you may have. Our team is always happy to help!

Tomy SX-Series Autoclave Sterilizer

Saves You Lots