eWater System

[Matthias Maiwald (KKH)]

Dear Colleagues,

The topic of the eWater System appeared on both the ACIPC and OzBug e-mail lists (I overlooked the ACIPC one initially) and I thought it would be worth writing a somewhat more detailed joint reply to both lists.

I have previously posted (to ACIPC) on what seemed a similar technology, the ActiveIon device.

I have looked at some of the available information concerning the eWater System, and even though I cannot make any final conclusions, I have a number of questions and issues of concern that I would like to share. If I were to look at purchasing the device, these would be some of the points that I would look at more closely.

(1) The description is that the system performs electrolysis of an NaCl solution and creates two solutions, one a (probably weak) bleach (NaOCl) and/or hypochlorous acid (HOCl) solution (not sure which one predominates), the other a sodium hydroxide (NaOH) solution. The bleach solution — according to the description — is microbicidal and can be used for disinfection, including disinfection in the food industry, in hospitals, even hand antisepsis. The NaOH solution — according to the description — is for cleaning.

(2) The question comes: What would be the difference between using the eWater system and just buying bleach and/or hypochlorous acid itself, which are cheap standard chemicals that are easily available?

(3) Has the system been tested by a manufacturer-independent (!) disinfectant testing laboratory with relevant expertise? Experience tells us that one cannot solely rely on manufacturer-provided test reports or manufacturer claims when it comes to disinfectants — preferable would be at least two independent test reports from experienced reputable labs.

(4) Has the system been tested by any of the available standardised testing protocols for surface disinfection (or other types of application, depending on the intended use)? There are, for example, US ASTM standards and European EN standards. The EN standard for surface disinfection is EN 13697, and such tests are typically done in variations (a) with or without organic load (“dirty conditions”) and (b) with or without mechanical action (simulating the wiping).

(5) If, for example, antimicrobial activity would fail in the presence of organic load, then a prior cleaning step would become highly critical. Organic load is, of course, an issue in the food industry, where one of the advertising targets lies.

(6) FYI, disinfectant testing and assessment is usually done in two steps, step 1 is testing in suspension — like the MBC (minimum bactericidal concentration) for antibiotics – and step 2 is testing under simulated practice conditions, e.g. surface disinfection on a carrier.

(7) Has any testing employed experimental controls that — in terms of biological plausibility — leave no other conclusions than what the machine produced killed the microorganisms and not (!) some other part of the application? (In the ActiveIon example, the microbial reduction achieved by one testing lab was similar to what one would expect from applying plain inactive water and wiping, but such a control was omitted).

(8) Is there a way to make sure that the disinfectant concentrations coming out of the machine are kept consistent and in an antimicrobially active range to fulfill their purpose? Meaning how are concentrations monitored and ensured that there is active disinfectant? Is there a testing method provided to measure the concentrations in daily use (in analogy to checking fridge temperatures in labs on a daily basis as part of quality control)? Apparently, electrodes age over time and may deliver electrolysis less consistently. Is there experience with stability of not only disinfectant concentration but also microbicidal activity over the intended period of machine usage (I presume years)? Also, how long are the prepared solutions stable after electrolysis and before application?

(9) The company address given on the website is an Australian one, but it is unclear to me if they are a distributor or the manufacturer. Some of the documentation appears to be from Japan; this may indicate that the Australian address may be a distributor.

(10) I saw two “research” publications on the website, both looked like research papers, but none had proper bibliographic information (journal name, year, volume, etc.). (I found one of these subsequently, with journal information, by putting the title into PubMed).

(11) A table on the website showing microbial test results (citing an article published in Japanese) misspelled quite a number of bacterial names. If someone claiming to have microbiological expertise is unable to spell some of the most common bacterial names, this should ring alarm bells.

(12) On the eWater website, there are three linked documents from RMIT University (origin: School of Civil Engineering). One is a brief Executive Summary, another a more comprehensive multi-page document, another what appears to be a conference poster. The Executive Summary appears to focus on cost, environmental and social factors, the bigger document has “report final” in its file name but has oblique “draft” written over the pages and no authors specified. The microbiology part is dubious. All three are written in a very positive tone, raising the question whether they might be industry-sponsored.

(13) The claim that the system can “sterilise” medical instruments appears unsubstantiated. From a solution like the one described, one would expect at best (!) high-level disinfection, but not sterilisation. Even claims for high-level disinfection would have to be substantiated by standardised testing, and it should be specified what types of instruments can be treated and under which conditions.

(14) It is proposed to use the electrolysed water for hand hygiene, but it is unclear to me how it should be useful for that purpose. NaOCl (bleach) is genuinely unsuitable (!) for hand hygiene, because in higher concentrations it would be damaging to hands and in lower concentrations it would take too long to kill microorganisms (alcohol hand rubs produce several log reduction in about 30 sec). Again, results from standardised tests would be needed.

(15) The main target is apparently the food industry, but it is also promoted for hospitals. Even if the product were “only” intended for the food industry, one would still expect that the system should fulfill basic claims concerning antimicrobial efficacy. Both industries are critical in terms of preventing infections.

(16) The company advertises with an endorsement from Austin Health. That would raise the question whether Austin’s Infection Control Department and/or Lindsay Grayson’s group has seen and/or endorsed this, or whether the company only liaised with scientifically untrained personnel, such as the housekeeping or kitchen department. The latter would be quite inappropriate. (We had an occasion here where a manufacturer tried to market a new product by circumventing the Infection Control Committee and went straight to Housekeeping).

I think that this system should be properly investigated by an institution or authority with the competency and clout to do this before it is used in the healthcare and food industry.

Best regards, Matthias.

—
Matthias Maiwald, MD, FRCPA
Consultant in Microbiology
Adj. Assoc. Prof., Natl. Univ. Singapore
Department of Pathology and Laboratory Medicine
KK Women’s and Children’s Hospital
100 Bukit Timah Road
Singapore 229899
Tel. +65 6394 8725 (Office)
Tel. +65 6394 1389 (Laboratory)
Fax +65 6394 1387

[cid:kkh4dd7.gif]kkh

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