Deprox Cowboys!

Cowboys Deprox

Incredibly, so-called “Hygiene Solutions Ltd” whose Deprox and Ultra-V machines are wheeled in to intensive care units and operating theatres on a daily basis, operates from the back of a dirty farming and livestock supplies warehouse, belonging to D&H Animal Husbandry. Here the Deprox units of their “On-call decontamination service” are stored between call-outs alongside pails of cattle feed and assorted agricultural and veterinary detritus.aisle-g-1

Here is another view of the real Hygiene Solutions.  I have added some notes for the non-technical reader.aisle-g-2

  1. Deprox machines
  2. RangerLick Cattle Plus Mineral Buckets
  3. Deprox vent cap accessory
  4. Deprox vent cap accessory telescopic poles
  5. Stepladders for short Deprox operators
  6. Mix of crumpled polythene, brown paper and sticky tape
  7. Pallets of Deproxin.

The covert camera video below gives a good idea of the grubby reality behind Hygiene Solutions polished sales presentations:

Video Deprox

These less than ideal surroundings are fertilised by a regular stream of D&H customers, arriving “fresh” from their chicken sheds, stables, pig barns and cow pastures, who trek malodorously  through “Hygiene Solutions Ltd” to the trade counter at the back of the barn.Deprox shit.PNG

Do you really want your ICU cleaned by cowboys?



Ultra-V – what’s inside your Spectrome?

Ultra-V croc box

Or should the question be, is ANYTHING inside your Spectrome? Following recent posts urging Ultra-V users to do some simple tests on their equipment, I have received several very remarkable reports. It appears that the Ultra-V will run a full cycle and “validate” that a hospital room has been successfully decontaminated even with two of the Spectromes placed outside of the door!

Either the special brand of UV light that the Ultra-V produces can pass through 50mm of wood, (in which case it is a grave danger to anyone in the building) or else the Spectromes are not really monitoring the UV output at all. Here is what Hygiene Solutions Ltd. claim for their “Patented Spectrome Technology”.

Ultra-V sic

Sorry – the quote above is verbatim. We know what they meant to say…

Ultra-V sic2

How exactly does the Spectrome “evaluate” the “extent of bacteria”? This is truly remarkable technology! And all this without even being in the room!

As the crocodile says, “Becuss it printed right dere in words, dat make it true.”

Ultra-V sic3

What is Spectrome indeed? I have a suspicion it might just be an empty box…

Ultra-V, Ward 7B & the dark side of the moon.

Ultra-V moon

Spare a thought for the unfortunate patients of Yeovil Hospital wards 7B and 8B. With the two wards hit by a nasty Norovirus outbreak, Director of Nursing Shelagh Meldrum is proposing to eliminate the germs WITHOUT the use of bleach or other “harmful chemicals” (i.e. disinfectant). Instead, she will put her trust (and her patient’s lives) into the hands of the notorious fake medical equipment company, Hygiene Solutions Ltd of King’s Lynn.

Ultra-V yeovil hosp.

The Ultra-V sounds like something from science fiction. Unfortunately, that is exactly what it is. A cheaply reverse-engineered copy of an obsolete American device, built in the back of a farm sundries warehouse, the Ultra-V is foisted on unsuspecting NHS by unctuous salesmen armed with a pack of outrageous lies, which can be disproved by anyone with a basic understanding of physics.

UV-C light, as generated by the Ultra-V is well known for its germicidal properties. So what exactly is the problem with the Ultra-V, and why should the hospital not use this instead of bleach?

The problem is that light travels in straight lines, and hence casts shadows. This is very evident from the photo of a crescent moon above. The dark side is very dark indeed, the sunlight does NOT wrap around corners to light up the lunar night.  This is just as true for UV light as for any other wavelength. Otherwise you could get a suntan at night.

Shadowed areas in a hospital room are not exposed to the UV radiation, hence are not disinfected. Conventional UV-C systems deal with the problem by using two or three light emitting units placed around the room to eliminate the shadowed areas, or otherwise require the unit to perform two disinfection cycles from two different locations in the room, thus ensuring that all areas are exposed at least once.

According to their sales brochure, the Ultra-V, by some miracle of optical technology can reach “shadowed areas, under bedside units and hidden corners” all from “one central location within each room”.


This miracle is achieved by “Spectromes”. These are apparently small light meters that are placed around the room to ensure that all surfaces get fully exposed. The exposure time is theoretically extended until the darkest “Spectrome” has had a full dose.

The only UV light received by a Spectrome that is in a shadow is the diffuse reflections from the lit surfaces of the room. Unfortunately most substances absorb UV-C radiation very strongly – far more than they do for visible light. In the UV-C world, almost everything non-metallic looks black.

Typical hospital surfaces absorb 95% of UV-C radiation, and scatter the rest. It follows that the shadowed areas are very dark, as at the most they can expect to receive 1/20th of the radiation of the directly lit areas. Consequently, if this scattered light is to disinfect the shadows, the process will have to be extended in duration 20 fold. Is this what happens?


The normal process time with the Spectromes fully exposed is 15 to 20 minutes. Place a Spectrome in the shadows, and the process might extend to 40 minutes at the max. (Try it, if you don’t believe me.) At this point, the Ultra-V is programmed to override the Spectrome, and turn out the UV lights, indicating that the process is complete. Just in case hospital staff might be suspicious, the Ultra-V automatically sends a cheerful email to the operator’s designated address, giving time, date location, and certifying that the room has been decontaminated to a log 4 to 6 standard.

To give an example of how dangerous this is, consider the bedrails on a standard hospital bed – these are high touch areas constantly exposed to the patient’s hands and every cough and sneeze. From its “single central location” the Ultra-V unit, obviously and indisputably will only illuminate one side of each bed rail. The other side will be nearly as dark, in UV terms, as the dark side of the moon in the photo above. A standard Ultra-V process will leave these areas highly contaminated. A simple test with standard Biological Indicator coupons will prove this. (Again, don’t take my word for it – try it.)

To compound the error, the Spectromes are narrow bottomed plastic boxes that have to be placed on a hard, level surface, usually the floor or a bedside cabinet. it is completely impossible for them to monitor small, high touch areas like the back of a bedrail.

Spectrome Ultra-V

So on the positive side, at least the unshadowed areas will get a thorough log 4 to log 6 clean? Sadly not. The following Journal of Hospital Infection article detailing a study at the Wye Valley NHS Trust, demonstrated an efficacy of less than log 1 for the Ultra-V.


The outlook for the patients of Yeovil hospital does not look very bright, at any wavelength, unless there is a change of heart.

Please Shelagh Meldrum, for the sake of both patients and staff, don’t throw away the bleach just yet…use your £50,000 white elephant if you must, but give the wards a good old-fashioned hypochlorite deep clean first!


Ultra-V…the exposé

Ultra-V and Spectrome are Hygiene Solutions’ attempt to penetrate the UV room disinfection market by using the same underhand and dishonest tactics as they used to promote the fraudulent Deprox device. As with Deprox, the data presented on their website is rudimentary – the more controversial claims are made in tender responses and sales presentations out of the public gaze,  where they are less likely to be challenged.

UV systems are very simple and hence there is little to choose between different manufacturers. From a marketing perspective, if a system can claim some unique and novel advantage, it can displace the competition and also sell for a higher price.

Ultra-V  is apparently the only UV system that can disinfect shadowed areas!  A hospital in the west of England that was approached by the company and told that  Ultra-V will  achieve a 4-6 kill log reduction of pathogens in “shadowed areas, the underside of beds,  behind units and in hidden corners.” (Fortunately, the hospital “smelt a rat” and cancelled the tender…)

Indeed, this is what the Ultra-V brochure says:


There is nothing unusual or novel about the “Ultra-V”. It has ten standard 5′ germicidal UV tubes, where more powerful competing systems may have up to 24. In fact, it is very similar to the American made Tru-D system on which the design was based.

The basis for the “shadowed areas” claim is that the system comes with a set of detachable “Spectromes” which are crude light meters that are in Bluetooth contact with the main unit. These meters are distributed around the room, including in shadowed areas, and the theory is that the process time is extended, if necessary, until the shadowed (i.e. indirectly lit) areas have received the full 4 to 6 log dose of UV light. Sure enough, if a “Spectrome” is placed in a shadow, the process time extends from 15 to as much as 40 minutes to give the extra dose.

The problem is this:

UV-C light is strongly absorbed by almost all floor wall and ceiling materials and paints likely to be found in a hospital room – far more so than visible light. A study of UV-C  disinfection systems in hospital rooms found that the UV-C reflectivity of standard paint was between 5% and 7%. In other words, if we could see the world in UV-C, the walls, floor and ceiling would appear to be essentially black.

The only UV light that reaches shadowed areas, i.e. areas not in direct line of sight of the UV tubes, is reflected, scattered light. These reflected rays have lost over 90% of their power, and as log efficacy of UV disinfection is linear with exposure time, the lamps will have to run for at least 10 times as long if the shadowed areas are to receive a full dose of UV radiation. In other words, if 15 minutes gives a log 4-6 reduction for directly exposed surfaces, the “shadow treatment” process as claimed for Ultra-V will take about 2 ½ hours.


This estimate is confirmed by the results of the study mentioned above, using a Tru-D machine, which is almost identical to the Ultra-V. The table below was extracted from the paper.


Here the unit is run for nearly 44 minutes in a 130 ft² room. (i.e. approx 11′ x 11′) The average log reduction of the 33 samples that were directly illuminated is log 3.41. The average log reduction of the 27 samples in the shadows was only log 2.01.

How then…does the Ultra-V achieve log4-6, in the shadows, in about 30 minutes?

The answer is very simple – it doesn’t. Regardless of what the shadowed “Spectromes” may demand, the system is set to a maximum run time of 40 minutes or so – because otherwise customers would complain. (The rapid process time is perhaps the greatest “selling point” of UV as compared to alternative processes. A system that ran for 2 hours or more would be uncompetitive, and would also damage and bleach materials in the treated area by overexposure.) However, for the hospital’s peace of mind, the machine will automatically generate and email a report stating that the room has been cleaned to log 4 standards.

Yes, but… Hygiene Solutions tested the efficacy with contact plates when the system was trialled, and the results were excellent!

The nice man from Hygiene Solutions is indeed very willing to do all the microbiological testing free of charge. To quote from a UK hospital that conducted a trial of the system:

” There was personnel on site from the company throughout the trial, the engineer conducted sampling and used 5 contact plate samples in each area the unit was used.  These samples were then sealed, labelled, logged with start and finish times and area sampled, these were then refrigerated in the company vehicle before being transported to their own laboratory for testing.”

I have no direct information for the Ultra-V testing, but former Deprox operators have reported that the Biological Indicators that they brought back from “validating” their Deprox processes were put on the sales rep’s desk and remained there indefinitely. There is little evidence that they were ever incubated or cultivated at all. Could it be that the graduate microbiologist at Hygiene Solutions can determine the results by intuition, without resorting to the old fashioned and time consuming process of incubating the samples?

However, if we assume that the plates are incubated and the results honestly reported, what does that tell us? Almost nothing, according to the following article by Michrochem Laboratory, who are the leading independent UV system testing lab in the USA.

“Unfortunately, environmental swab studies are confounded by several problematic technical factors, described in detail below. Taken together, these factors make environmental swab studies some of the least reliable means of testing UV effectiveness.”

“The first major confounding factor of environmental swab studies on UV efficacy determinations is mathematical in nature. Initial microbial populations in indoor or hospital environments are often low. There are are frequently only about 100 total bacteria per 10 square centimeters of surface. That is not much of a challenge for many UV systems, meaning the extent of the UV effects may not be fully measurable. On top of that, lab techniques used to enumerate microorganisms on the swabs often result in a poor limit of detection, meaning that viable cells on the surface may not be detected if they are present in low numbers.”

“The second problematic aspect of environmental swab studies is related to microbiological technique. Populations of microorganisms often vary widely from one spot to the next, even on the same surface. If the same exact location were swabbed before and after treatment this would not be a problem, but the act of swabbing a surface or sampling it with a press-plate effectively cleans the surface, removing microorganisms in the process. Swabbing pressure and surface area are also variable. Even the best researchers find it challenging to swab different surfaces, yet maintain the same pressure and cover the same surface area. Doorknobs and sink handles, for example, are more challenging than a table section.”

The  65mm RODAC contact plates used by Hygiene Solutions have an area of 33cm².  From the data above, a typical bacterium density is 10 CFU/cm², so the “before” plate might be expected to show about 330 CFU. In order to demonstrate a log4 reduction, it is obvious that the plate would have to show at least 10,000 CFU.

To compound this, the contact plate obviously removes the bacteria from the patch tested. Hence almost inevitably, regardless of whether any treatment has taken place or not, a second plate applied to the same patch will have a lower colony count –  because the first plate effectively cleans the surface!

The only way to prove a log4-6 reduction is to use a mixture of log4 and log6 biological indicators in both the shadowed and unshadowed areas. As C. difficle spores are much more resistant to UV than vegetative organisms, and are also one of the most common and threatening of the serious pathogens, these should be the test organism of choice. Because of the inherent conflict of interest in a decontamination equipment supplier doing its own testing, an independent test laboratory, or the hospital’s own microbiology department should do the testing. If the equipment supplier is reluctant to agree to this, or offers to take the samples and “have them tested by an independent lab” –  walk away!

Yes but…there are published papers in highly regarded medical journals that demonstrate the efficacy of the Ultra-V. So it must work as claimed!

The Journal of Hospital Infection published the following article in July 2016.


A single sentence sums up the results of this study:


Touch plate tests were done before and after a manual clean, then after a 20 minute Ultra-V cycle. There is no suggestion that shadowed areas were tested. The reduction attributable to the Ultra-V is therefore a reduction from 19.3 CFU to 2.3 CFU. This is a little less than a ten fold reduction, i.e. it is less than log 1.

Just to remind ourselves, Hygiene Solutions claim a log4-6 reduction even in shadowed areas. That is a reduction of between 10,000 and 1,000,000 fold.

The actual reduction achieved was 8 fold – rather less than log 1.

Court order re. false and misleading statements

Interestingly, Ultra-V’s alter ego, the Tru-D device is also in trouble…ultra-v-5

Sadly, the Ultra-V fraud has human consequences – as Hygiene Solutions point out in their brochures, some of their customers are using this shockingly inadequate log 1 system to clean high risk areas such as operating theatres.


Finally, to add insult to injury, Hygiene Solutions are trying to sell this contraption, which is essentially a standard fluorescent light unit on wheels, for an astonishing £50,000+


Nelson Bridwell

So what is the solution? Multiple smaller light sources around the room? Reflective wall paint? A mobile light source that drives around the room, following a stripe on the floor?

Richard Marsh

Yes, all of the above are interesting ideas, and could help. The real issue here is the false claims that can lead hospital staff to assume an area has been sterilized when in fact it has not. Shadowed areas should be cleaned manually on a regular schedule to avoid them becoming reservoirs of infection. This necessity does not detract from the usefulness of UV disinfection as a whole. However, if these shadowed areas are omitted from regular manual cleaning on the false basis that they have been UV sterilized, this could actually lead to an increase in HAIs as a result of a UV system being introduced. Tragically, the fatality rates from HAIs are high. In the USA 1 in 25 patients acquire an HAI from a hospital stay, and 1 in 9 of those infected will die. The dishonest promotion and widespread use of ineffective systems such as the Ultra-V and Deprox displaces alternative systems that are both effective and honestly characterized, thus inevitably causing sickness and death of vulnerable hospital patients. This is known euphemistically in the healthcare profession as “increased morbidity and mortality” – nonetheless, the victims of this fraud are just as irrevocably dead as if they had been slain by a terrorist attack.