FDA 510(k)

The TANGO3 Water Storage Tank with Ozone Disinfection System has been assigned FDA 510(k) 093641

Product Information

WOZ–250–PE

Water Storage Tank with Ozone Disinfection System

FDA 510(k) 093641

The Tango system has been installed with a number of water systems, both new and old.  They include systems from MarCor, Isopure, Better Water, Ameriwater and Zyza Tech.  When installed with a new system, the water vendor does not provide the water storage tank or the distribution pump.  Those items are supplied by Tango.

System Description

There are three major components in the system, the water storage tank, the distribution (loop) pump and the control center.

Functional Description

The control center is an ABS enclosure mounted on a powder coated steel frame that is on plastic skids.  The ozone generator and atmospheric ozone destruct system are openly mounted on the back of the enclosure.  Inside the enclosure is the Programmable Logic Controller (PLC), a variable frequency drive (keeps the loop velocity at 4 feet per second), a Mettler Toledo Meter that reads conductivity, temperature and ozone to a 1% accuracy.  A Human Machine Interface (HMI) touch screen has graphics that show pump movement, flow movement and ozone generation.  It also displays velocity, temperature, conductivity and, if in disinfection, the ozone level.  Dates and times for automatic disinfection are programmed from the touch screen.

The Water Storage Tank acts as the water storage tank for the dialysis facility, but is designed to inject ozone via a venturi during disinfection with ozone.  The system includes the distribution pump to circulate water from the bottom of the storage tank, through the distribution loop and back into the storage tank.  Ozone levels are monitored where the water is returned to the tank, and controlled to range between 0.2 ppm and 0.3 ppm of ozone.  Tango also controls the RO System, turning it on when water is needed in the storage tank and turning it off when the tank is full.  Loop velocity and flow are also monitored leaving the storage tank and returning to the storage tank to verify that no water is being used during disinfection.  Storage tank levels are also monitored for the same purpose.  Since disinfection is normally done automatically during non-operational hours, an alarm, indicating water is being used, would cause the distribution pump to shut down for five minutes before proceeding with the disinfection.  If disinfection was started while patients were being dialyzed – an obvious error – the delay forces a staff member to look at the system.  The alarm screen would say “If you are dialyzing patients, abort disinfection now.”  Under this circumstance, the alarm will occur early enough to avoid enough injection of ozone (within the first four minutes) to require flushing it out before continuing dialysis treatments. 

After disinfection, the Tango system will purge the storage tank and loop of residual ozone and endotoxin.   It will then refill the storage tank for the next scheduled shift of dialysis patients.  Since this is done automatically, it reduces staff overtime, and allows more frequent disinfections at the date and time you choose.

The Tango system also utilizes an ozone destruct system to control ozone levels in the air.  This is accomplished by venting the air, at the top of the storage tank, through a vent line that goes into a cylinder containing a catalyst that destroys ozone.  Heat is applied to the catalyst to make it more efficient.  This will control atmospheric ozone concentrations during disinfection to keep them below EPA and OSHA recommendations of 0.1 ppm for 8 hour exposure, or 0.3 ppm for a 15 minute exposure limit.

Again, ozone is the most effective germicidal agent available in the marketplace.  It is relatively unstable and must be continually produced during a disinfection cycle.  High temperature and high or low pH water increase the instability significantly, and will increase the time required to reach desired ozone levels.

Many water distribution loops have an ultraviolet light and/or ultrafilters, both capable of destroying or hindering ozone generation.   Ozone (O3) is destroyed immediately by UV light, reverting it back to oxygen (O2).  This means the Tango system must turn off a UV light when disinfecting with ozone, and also must bypass ultrafilters to make sure they will not interfere with ozone generation. Ozone also breaks down – reverting to oxygen – as it kills organics.  This means once desired ozone levels are reached, most of the pathogens have already been destroyed.  For example, one of our tests had bacteria TNTC (too numerous to count).  Within 20 minutes, the CFU’s were 4.  The ozone level was still 0.0 ppm.

I hope this information has been helpful to you in your understanding of how the Tango system functions automatically to provide ozone disinfection safely and effectively in dialysis facilities.  I encourage you to call and discuss any questions you may have with CEO, Hugh Doss, or the technical manager, Fred Spencer.