What type of water should be used with the autoclave and why?

• A. Distilled water, because it has the fewest dissolved minerals
• B. Deionized water, because it is highly pure
• C. Tap water, because it is convenient
• D. Filtered water, because it removes taste

Answer: (A)

Using water with minimal mineral content in an autoclave is essential for maintaining steam quality and protecting both the sterilization process and the equipment. Distilled water has essentially all dissolved minerals removed, so it produces very pure steam and leaves little to no mineral deposits in the boiler, hoses, and valves. That reduces scale buildup that can hinder heat transfer and clog vents, and it minimizes residues on instruments after sterilization, helping ensure a reliable sterile barrier. Tap water brings minerals and chlorine that can form scale and cause corrosion or deposits; filtered water may reduce tastes but often still contains minerals that can lead to buildup; deionized water is extremely pure but can be more aggressive toward metal components over time. For consistent, safe sterilization, distilled water is the best choice.