Do ice machines spread legionnaires’ disease?

Do ice machines spread legionnaires’ disease?

by | Jun 25, 2019 | Blog

Given that the legionella virus is only active between the temperatures of 20oC and 45oC, it seems reasonable to assume that, if you use an ice machine – or have an ice machine or cool water dispenser integrated into your fridge/freezer – you ought to be safe from the bacteria. 

However, Legionella is merely dormant at low temperatures, and as soon as the ice thaws, it becomes active again. Given the mechanical nature of ice machines, any water held in pipes positioned close to the generator could be stored at an increased temperature that allows legionella to become active. 

In 2013, a patient died at a hospital in Pittsburgh in the US as the result of contracting legionnaires’ disease from legionella bacteria in an ice machine. The patient had choked on an ice chip which enabled the bacteria to enter his lungs. Two other patients also contracted the disease, and a further outbreak in a hospital in Brisbane, Australia was discovered to have its origins in an ice machine. 

So the simple answer is: yes, ice machines do spread legionnaires’ disease. 


How to prevent Legionnaires’ disease in ice machines


Any equipment that uses water needs to be regularly checked, cleaned, descaled and disinfected, and this includes ice machines. It is recommended that you dismantle the parts to do a thorough clean at least once a year in order to minimise risks. 

As this is drinking water, be extremely careful about the chemicals you use to clean the piping and elements, and flush thoroughly to ensure traces of both the chemicals and the bacteria have gone. A 2017 academic study published in the Open Forum Infectious Diseases concluded that: “Manual interventions have the ability to work, but need to be strictly followed and maintained. Continuous disinfection with Monochloramine was most effective as preventing Legionella colonization and was easiest to maintain.” 

If you have any concerns about ice machines or any aspect of your water system, contact us to arrange for a risk assessment or testing

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