Script for explanation of anti-Legionella association announcement poster
Hello everyone.
I’ m going to talk about the “Registration System of Anti-Legionella Chemicals and Results ofExternal Quality Assessment for Legionella Testing.”
The Japan Association of Anti-Legionella Chemicals for Cooling Water was established inJune 1991 in Japan by private water treatment companies with the goal of providing effective,
highly safe anti-Legionella water treatment chemicals and disseminating correct knowledge
regarding Legionella contamination of water environments. Currently there are 17 member
companies. Our activities include public awareness initiatives to prevent Legionnaires’
disease, maintenance of an anti-Legionella water treatment chemical registration system, andactivities intended to improve the precision of Legionella testing.
First I would like to introduce our public awareness initiatives aimed at preventing
Legionnaires’ disease. We put together the “Guidance on Prevention of Legionnaires’ Disease
in Cooling Water Systems” for cooling tower managers, and have been distributing it since2001. We also offer information on the prevention of Legionnaires’ disease via a website, andconduct public awareness activities to prevent Legionnaires’ disease in cooling water used in
air conditioning.
Next I will explain our anti-Legionella water treatment chemical registration system. We
standardized the methods used by each company to evaluate the effectiveness and safety ofwater treatment chemicals, and in 1992 established voluntary standards for anti-Legionella
cooling water treatment chemicals. These voluntary standards comprise (1) Objectives, (2)Applicable scope, (3) Confirmation of efficacy, (4) Confirmation of safety, (5) Labeling items,and (6) Prevention of environment contamination through discharged water. Since 1993 wehave operated a system for registration of products that comply with these voluntarystandards, and published a list of registered chemicals of the Association. This list ofregistered chemicals is revised with products added and removed as required, and the latest
version can be viewed on the website. Currently there are 174 chemicals registered. The
efficacy of registered chemicals against Legionella is indicated by tabulating the results ofLegionella testing conducted by each company. The graph in the center of this poster shows
the ratio of Legionella detected at 100 CFU/100 mL or higher in registered chemical treatment
systems and systems not treated with disinfectant based on Legionella testing data for coolingwater systems for the 10-year period from 2011 to 2021. Each plot is the result of analyzingover 10,000 data items. We know that the registered chemical treatment systems are more
effective at suppressing the growth of Legionella than untreated systems.

Next I will explain our activities aimed at improving the accuracy of Legionella testing.
Legionella testing is vital to understanding the state of Legionella contamination in target
water systems and evaluating the efficacy of measures against it, and thus must be highlyaccurate. We are working to improve the accuracy of the Legionella testing undertaken bymember companies. While Legionella testing methods are based on those listed in ISO
11731:2017, there are slight differences in the methods employed by each company. We
endeavored to standardize testing methods in order to improve the accuracy of Legionella
testing in cooling water systems. Details on the standardized testing methods are available on
the website. Since 2013, when standardization improved the testing methods of each membercompany, we have participated in the External Quality Assessment for Legionella Isolation run
by Public Health England (now the UK Health Security Agency). The standardized testing
methods were revised in 2015 in order to achieve greater testing accuracy. The results ofthese efforts are shown in the graph in the lower section of the poster. Although there isvariation apparent in the results from each company, there is a trend towards improved Zscores apparent since the 2015 revisions to testing methods. The Association has establisheda system to certify member companies that participate in the external quality assessment andmeet certain standards. The blue certification mark at the bottom right of the poster can bedisplayed on testing results reports and other documents issued by member companies thathave received this certification.
Going forward, the Association will work to improve the accuracy of Legionella testing on
which sanitary management of cooling water systems is based. Additionally, we will moveahead with public awareness activities regarding measures against Legionella bacteria andwork to prevent Legionnaires’ disease, which is transmitted through cooling water systems.
Thank you very much.