Germophobia: ASPE turns to Montana State lab for faucet study

DES PLAINES, ILL. — The American Society of Plumbing Engineers Research Foundation has contracted with Montana State University, Center for Biofilm Engineering to find out if electronic hands-free faucets are germier than manual faucets. The issue was brought to the forefront when Johns Hopkins Hospital released a report saying that Legionella bacteria grew inside the mechanisms of hands-free faucets. 

DES PLAINES, ILL. — The American Society of Plumbing Engineers Research Foundation has contracted with Montana State University, Center for Biofilm Engineering to find out if electronic hands-free faucets are germier than manual faucets. The issue was brought to the forefront when Johns Hopkins Hospital released a report saying that Legionella bacteria grew inside the mechanisms of hands-free faucets.

ASPE is seeking benefactors to help fund the research.

Members of the plumbing industry were taken by surprise when Johns Hopkins Hospital released results of a study on March 31, 2011, that said that electronic hands-free faucets are not as sanitary as manual faucets. The internal components of electronic hands-free faucets can serve as breeding grounds for Legionella bacteria, the hospital said. Plumbing manufacturers and specifiers greeted the news with consternation and alarm, with most learning about the Johns Hopkins study in the news media. The Johns Hopkins study of faucets in use in its own facilities was released during a seminar at a scientific conference; it was not a peer-reviewed laboratory study.

Although the faucets cut daily water consumption by well over half, Johns Hopkins researchers identified Legionella growing in 50% of cultured water samples from 20 electronic faucets in or near patient rooms on three different inpatient units, but in only 15% of water cultures from 20 manual faucets in the same patient care areas. Weekly water culture results also showed half the amount of bacterial growth of any kind in the manual faucets than in the electronic models.

“Plumbing Manufacturers International became aware of the Johns Hopkins study on the use of hands-free faucets in hospitals via the news media on March 31,” Executive Director Barbara Higgens said in a statement in April 2011. “We have reached out to Dr. Lisa Maragakis, M.D., M.P.H., senior study investigator and infectious disease specialist at Johns Hopkins, to obtain a copy of the study for our review and input. Without having seen the study, it is difficult for us to identify how, if at all, their findings apply to the products our members manufacture. We can say with confidence, however, that our products meet the highest industry standards and that hands-free faucets have been safely in use around the world for decades, and have provided many benefits, including water conservation and minimizing the spread of germs from contact. We constantly seek to improve industry standards and performance and look forward to working with the team at Johns Hopkins to review and discuss their findings.”

Because the publication of the study raised so many serious questions, the American Society of Plumbing Engineers facilitated an industry-wide meeting in June 2011 that included representatives of 14 plumbing industry organizations representing manufacturers, contractors, engineers, testing laboratories, model code bodies, and water utilities. 

Industry stakeholders have agreed that controlled laboratory research is necessary to determine if electronic hands-free faucets are susceptible to internal contamination and how that compares with surface contamination of manual faucets. That research focusing on a single variable —electronic actuated valve verses mechanically actuated valve, all other elements being equal — can form the baseline for future bacteriological studies such as material type, effect of aerators, airborne biota influence, water temperature, effectiveness of disinfection procedures and biocides.

To date, all published literature reviewed by members of the American Society of Plumbing Engineers Research Foundation Project Team found that current knowledge is based on field studies rather than tightly controlled experiments. In many instances, the published studies generate more questions than they answer. Many times the conclusions of the studies are thinly supported by the data, the project team said, leaving plumbing practitioners without enough information to make a fully informed decision about faucet selection.

The ASPE Research Foundation Project Team found a study entitled Electronic-Eye Faucets: Legionella Species Contamination in Healthcare Settings, published in the journal Infection Control & Hospital Epidemiology, March 2012, that concluded, “Electronic faucets were more commonly contaminated with Legionella species and other bacteria and were less likely to be disinfected after chlorine dioxide remediation. Electronic faucet components may provide points of concentrated bacterial growth.”

The study’s authors also wrote, “As a consequence of the study findings, all electronic-eye faucets were replaced with manual faucets in the authors’ institution. Although the study confirms previous reports of electronic faucet contamination with non-fermentative gram-negative bacteria and unequivocally provides information about the extent of Legionella species colonization, there is insufficient evidence to recommend the removal of electronic eye faucets from all healthcare institutions.”

Because none of these field studies is definitive, leaving manufacturers, contractors and engineers uncertain about what to do, the ASPE Research Foundation is collaborating with Montana State University, Center for Biofilm Engineering (CBE) on a laboratory study, Biofilm Growth and Detachment in Manual vs. Automatic Faucets.

The work will assess biofilm growth, accumulation, and detachment in both automatic and manually operated faucets under identical flow conditions when exposed to potable water over a period of four months.

CBE will study biofilm accumulation in and detachment from both electronic and manual faucets in a controlled laboratory environment. Electronic and manual faucets will be acquired from plumbing manufacturers and installed in CBE laboratories. Both sets of faucets will be plumbed to municipal water supply lines and will be controlled by timers, which will operate the faucets in a regular manner (run time, hold time, and water temperature). Run time, hold time, and temperatures for both hot and cold water use will be based on realistic usage patterns. The test will run for approximately four months, during which periodic samples will be taken from each faucet in the test. Samples will be taken both from effluent water from the faucets as well as swab samples from interior surfaces of the faucet.

Incoming water samples will also be taken at several points in the system to assess bacterial loading into the faucets. Influent bacteria will be non-pathogenic, drinking water organisms naturally present in Bozeman tap water. During the initial testing of the system, specific pathogens such as Legionella will be cultured along with general bacteria.

The data collected will provide a basis for concluding whether faucet valve type alone is a statistically significant factor in bacteria growth.

Additional information on the study and on how to donate to the research is available from the ASPE Research Foundation, 2980 S. River Rd., Des Plaines, Ill. 60018; 847/296-0002, fax: 847/296-2963.

 

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