Isothiazolin Uses For Controlling Bacteria and Legionella in Cooling Water Systems

Isothiazolin, commonly used at 1.5%, is used in recirculating cooling water systems and closed loop systems to control microbial growth. The product is effective over a wide pH range against the microorganisms typically found in these systems. Its benefits of Isothiazolin is it is an excellent broad spectrum microbiocide. It is effective over the range of pH’s found in typical cooling systems. It does not adversely affect cooling water treatment components. It is non-foaming and compatible with halogen biocides

Isothiazolin is normally shot fed according to the label instructions. The technical specialist servicing the facility will provide specific treatment control levels based on system conditions. Isothiazolin is normally fed neat directly from the shipping container. Tanks, pumps, piping and valves should be made of stainless steel, polyethylene, or PVC.

Isothiazolin is considered a non-oxidizing biocide. When legionella preventie feeding it, you should feed at minimum 150 ppm of product as quickly as possible to your water system. Use bacteria dipslides to monitor bacteria development. To effectively treat cooling systems, you should use an oxidizers, such as sodium hypochlorite, and alternate non-oxidizers such as glutaraldehyde and isothiazolin.

Bacteria dipslides are used to provide a qualitative look at what organisms are present. With these slides, you dip it in water for 5 seconds and wait 24 hours. Red dots will appear when bacteria is present in your water. Maintain less then 10,000 bacteria counts in your process water at all times. This test should be done with a free chlorine test to confirm you have a successful treatment program.