ASHRAE Targets Legionellosis - SETRI

Industry Q&A: William McCoy, PhD

With the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) new standard to help prevent legionellosis from building water systems to be released before the end of year, Healthcare Building Ideas caught up with Committee Chair William McCoy, to find out how ASHRAE Standard 188P “Prevention of Legionellosis Associated with Building Water Systems” will impact the healthcare industry.

Please describe the main drivers and factors that brought about ASHRAE’s attention to Legionellosis in the form of this developing standard.
ASHRAE first published a position statement about building-associated Legionellosis back in 1998. Then, in the year 2000, Guideline 12, Minimizing the Risk of Legionellosis Associated with Building Water Systems, was published. Both of these documents were in response to membership concern about this very significant problem.
In the U.S. every year, several hundred million dollars are spent on direct healthcare costs caused by the many thousands of cases that end up in hospitals. The indirect costs of these cases are at least an order of magnitude more.
The estimated number of deaths due to building-associated Legionellosis is 4,000 annually, according to the Occupational Safety and Health Administration.
Legionellosis is by far the most significant building water system health-related issue today. There is a great deal of information about how to analyze and control the hazard that causes Legionellosis. However, there is almost nothing about what facility managers and owners should do with all that information.
ASHRAE Standard Project Committee 188 proposed that there should be a standard practice developed to specify what should be done with all of that informative information about how to control Legionella and thereby prevent Legionellosis.
“Standard 188P, Prevention of Legionellosis Associated with Building Water Systems,” is a standard practice specification for what to do.

From which entities is the standard’s committee drawing its expertise and input in the development of this standard?
The committee is comprised of 22 voting members and about 20 non-voting members. The roster includes the leading experts from academe and the industry. There are four members from the Centers for Disease Control (CDC) who represent the core Legionellosis expertise from the CRC.
Two members are university professionals who have focused their 30-year careers academic on the subject. The manager at Ford Motor Co. who leads development of their corporate plan is also a voting member, and two members are from the U.S. General Services Administration.
Our members are also members of the American Society for Healthcare Engineering, the International Association of Plumbing and Mechanical Officials, the American Society of Plumbing Engineers, the American Water Works Association, the American Society for Microbiology, and many other professional organizations.
Three of four voting members are world-class water treatment professionals and another four have spent many years in the industry. An additional four have dedicated their careers to the cooling water device manufacturing industries while several others are experts in analytical microbiology.
Our international voting member is from Australia and was the chair of the group that wrote standards for preventing Legionellosis in that country.

ASHE has described this standard as a “game change,” and you were quoted as saying that the standard’s implementation has the potential to prevent thousands of Legionellosis cases every year. Although the details are still being revised and developed, can you share a few highlights as to how the standard will potentially make such a significant impact, particularly in healthcare facilities?
The cause of Legionellosis and how to prevent it has been known for 30 years. As mentioned, there are at least 13 guidance documents in the U.S. already published and widely available, giving specifics about how to control the hazard that causes the disease.
But there is no specification for what to do with all of that information. ASHRAE Standard 188P provides that specification.

What do hospital owners need to know about this standard in anticipation of its implementation?
Hospital owners should know what is required to comply with the standard. As such, here is an executive summary:
“Compliance with Standard 188 requires that facility owners/managers establish a team with accountabilities and responsibilities that will develop a hazard analysis and control plan to prevent Legionellosis associated with their facility. The first job for the team is to describe the building water system using simple process flow diagrams of the potable and utility water systems. Each processing step in the building water system (such as for examples, heating, conditioning, filtering, etc.) must be named and numbered on the process flow diagrams. Then the team is required to perform systematic hazard analysis to indicate the potential risk at each step listed on the process flow diagrams, whether or not the risk is significant and what control could be applied at that step. Every step at which control is applied is to be designated a Critical Control Point. For every Critical Control Point, the team must establish critical limits, a monitoring plan and corrective actions for what to do if the critical limit is violated. Note that critical limits and monitoring refer to the control method applied (for example, the chlorine concentration or the temperature); critical limits do NOT refer to Legionella test results. Finally, the team must provide evidence that hazards have been controlled under operating conditions (this is called Validation) and the team must provide confirmation that the plan has actually been implemented (this is called Verification). Validation can include Legionella test results but other data are also acceptable such as disease surveillance. Verification should include all critical limit monitoring data, corrective action logs, meeting notes and supporting documents.”
Providing some more background on the standard, an article penned by McCoy and his colleague William E. Pearson, CWT, is available on his company’s website, Phigenics.


A SETRI no Brasil já realiza o processo de Avaliação de Risco pelo método HACCP e participou com opiniões no novo Standard 188P da ASHRAE.
Phigenics é um parceiro técnico da SETRI.