Water purity is one of the least understood areas of science across all global cultures. There is no shortage of people who boast about having the purest water in their city, or even in the bottles they purchase. The city of Saint Augustine, Florida boasts of “The Fountain of Youth” and more than one manufacturer of home water filtration technology fill their advertisements with claims of high purity.

I thought it might be fun, even shocking to look at some different water purity requirements for various processes and needs in our every day lives. The science may shock you. Let’s take a look.

Two of the most critical needs for ultra-high purity water are the Electronics and Power Generating Industry. They both require water that is virtually free of any contamination. Next in the strictness of water purity would be the preparation of reagents in R&D and Hospital laboratories. Reagents would be any chemical preparations needed for analytical purposes. Next in line for level of water purity, would be what is called Water For Injection (WFI). Running in last place in this comparison, but not far behind would be water used for spot-free rinse in car washes.

Many find it surprising that water required for spot-free car washes is about the same purity as water that is used in I.V bags. Even crazier is how much more pure water used in electronics, power production and even making chrome bumpers has to be cleaner than the water used in chemicals and solutions that are placed inside our body. Even water used in kidney dialysis is too “dirty” for many of today’s high-tech industries.