Why Distilled Water Is Required for Autoclaves and Medical Sterilization
In healthcare facilities, laboratories, and tattoo studios across the GTA, autoclaves are the gold standard for sterilizing instruments. But many operators do not realize that the water they use in their autoclave is just as important as the sterilization cycle itself. Using anything other than distilled water can damage your equipment, compromise sterilization, and lead to costly repairs.
How Autoclaves Work
An autoclave uses pressurized steam to kill bacteria, viruses, fungi, and spores on medical instruments, lab equipment, and other items that require sterilization. The process involves heating water to produce steam at temperatures above 121°C under pressure. This steam penetrates packaging and instrument surfaces to achieve complete sterilization.
Because the entire process depends on water being converted to steam and back, the purity of that water directly affects the quality of sterilization and the longevity of your autoclave.
What Happens When You Use Tap Water
Tap water contains dissolved minerals — calcium, magnesium, iron, and silica among others. When tap water is heated in an autoclave, these minerals do not evaporate with the steam. Instead, they accumulate inside the chamber, on heating elements, on valves, and on the instruments being sterilized.
Over time, mineral scale builds up and causes a cascade of problems. Heating elements become less efficient, requiring more energy and longer cycle times. Valves and gaskets corrode, leading to pressure leaks. Scale deposits on instruments leave white residue that can interfere with surgical procedures. Eventually, the autoclave may fail entirely — and replacement costs for medical-grade autoclaves can run into tens of thousands of dollars.
Distilled Water: The Manufacturer-Recommended Standard
Virtually every autoclave manufacturer — from Midmark and Tuttnauer to SciCan and Ritter — specifies distilled water with a total dissolved solids (TDS) reading below 10 PPM. Puretap distilled water consistently tests between 0 and 5 PPM, well within manufacturer specifications.
Using distilled water ensures clean steam production, prevents mineral buildup, extends the life of heating elements and gaskets, and keeps sterilized instruments free of residue. It is not just a recommendation — for many manufacturers, using non-distilled water voids the warranty.
Who Needs Distilled Water for Autoclaves?
Any facility that operates an autoclave should be using distilled water exclusively. This includes medical clinics, dental offices, veterinary practices, tattoo and piercing studios, nail salons offering implements sterilization, laboratories, and pharmaceutical facilities.
For smaller operations using tabletop autoclaves, our 18-litre bottles are the perfect size. Larger facilities such as hospitals, dental group practices, and laboratories may benefit from our 1000-litre tote fills for higher-volume needs.
The Cost of Not Using Distilled Water
A single autoclave repair call can cost hundreds to thousands of dollars. Replacement heating elements, descaling services, and valve repairs add up quickly. A regular supply of distilled water costs a fraction of a single repair visit and protects your investment for years to come.
More importantly, compromised sterilization puts patients and clients at risk. Regulatory bodies such as the Royal College of Dental Surgeons of Ontario (RCDSO) and public health inspectors require documented sterilization protocols — and using the correct water is part of compliance.
Contact Puretap to set up regular distilled water delivery for your autoclave. We serve medical clinics, dental offices, tattoo studios, and laboratories across the Greater Toronto Area.
Appreciate the effort you put into this.
This really helped me a lot.