A Tangled Web…

Oh what a tangled web we weave, When first we practise to deceive!

Sir Walter Scott


Thirty-nine misleading, dishonest or fraudulent statements from Hygiene Solutions.


The innovative and highly efficacious Deprox bio-decontamination system achieves a log 6 reduction of even the most virulent of organisms, significantly reducing the risk of cross infection to its next occupant.


Fraudulent – there is no credible evidence that Deprox achieves a log6 reduction of ANY organism.


Cambridge graduate microbiologist Rick Fentiman, the company’s technical director, said: “There is a lot of evidence to support the fact it can reduce outbreaks by half the time it takes to manage an outbreak using traditional methods.”


Fraudulent – Rick Fentiman founder and director of the company, is NOT a microbiologist, and has no university level qualifications whatever.


The Deprox system is designed, manufactured and tested to exacting British and International standards, including ISO 14001, ISO13485, ISO9001 and is CE marked. (Sheffield Teaching Hospitals Response to Tender, 2014)

Fraudulent – Hygiene Solutions does not have ISO13485 accreditation. (This is the ISO standard for medical equipment manufacture)


The DEPROX delivers a particularly significant contribution to society because, as it is so effective in killing C. Diff spores, it actually saves a significant amount of lives each year. (Royal Marsden Proposal 2015)

Therefore, if it is ineffective, and has displaced competing systems that do genuinely give a log6 disinfection, it must contribute to a significant number of deaths each year.


With the real-time monitoring function of the Process Analyser, the Deprox system is intelligent as to concentrations of hydrogen peroxide in the treatment environment. (Sheffield Teaching Hospitals Response to Tender, 2014)

Wrong – The Deprox has no hydrogen peroxide sensor whatever.


The Deprox HPV process is residue free and completes the decontamination cycle without reaching ‘dew point’ or leaving any chemical residues on surfaces within the room. (Sheffield Teaching Hospitals Response to Tender, 2014)

Untrue – a visible deposit of silver nitrate is left on surfaces close to the machine.


In this ITT response, we bring to you the Deprox™ decontamination system developed at Addenbrooke’s Hospital in Cambridge (Sheffield Teaching Hospitals Response to Tender, 2014)

Although fresh to the UK from Holland, the DEPROX is already established in leading hospitals for use in both the prevention and control of infections. (Royal North Shore Proposal 2012)

Fabrications – Deprox was NOT developed at Addenbrookes hospital – it was derived from the IC-4 designed in the Netherlands, and reverse engineered in King’s Lynn.


We now operate in 16 countries worldwide.


Fabrication – Deprox is used in 4 countries at the most.


Since starting in 2007, Hygiene Solutions, based in Hamlin Way, Hardwick Narrows Estate, now has dedicated premises for production, service, stock and customer service as well as offices in Australia, the US and working facilities across the UK.


Misleading – Hygiene Solutions still operate from some spare rooms and a mezzanine in an anonymous agricultural sundries warehouse – exactly where it started.


We validate every process and provide you with a clear and structured report, as well as expert advice, to ensure the environment is safe for patient admission.


Specious – if an honest validation were made, the process would be shown to be ineffective.


Deprox® is a fully computer-controlled vaporising system using a hydrogen peroxide solution, which has been proven to achieve a log-6 reduction in its efficacy.


Utterly unfounded, there is no credible evidence, let alone proof, that Deprox achieves a log6 reduction of any known pathogen (Presumably they mean a reduction in pathogens, not a reduction in efficacy)


Deprox® gives hospital staff the assurance that full decontamination has taken place and that the new patient is not at risk from cross-contamination.


Fraudulent and dangerous.


… the Deprox decontamination system is independently validated to achieve a 6-Log reduction of pathogens in the environment, including C. diff and Bacillus subtilis spores as well as the vegetative organisms MRSA and Staphylococcus Aureus. Please see Appendix 1, the “TNO Report” which validates the efficacy of the IC4™, the patented technology base to the Deprox system. This testing set out to evaluate the efficacy achieved by the Deprox technology on an extensive range of surfaces, positions and angles to best replicate the typical busy hospital environment (Sheffield Teaching Hospitals Response to Tender, 2014)

Deceptive, misleading, false:
The TNO report relates only to the IC-4 made by Infection Control BV, not Deprox designed and manufactured by Hygiene Solution Ltd
The IC-4 was tested in a room of only 49m3,(TNO report p15) where Deprox is claimed to disinfect rooms of 380m3
The IC-4 was set to give approximately double the hydrogen peroxide concentration that the Deprox process achieves.
The IC-4 took 150 minutes to eliminate the C. difficile and B. Subtilis spores, (TNO Report p2) but the Deprox “Decontamination phase” is only 90 minutes.
The BIs (pathogen samples) in the TNO test were all laid out in a horizontal plane, facing upwards, within 2.5m of the machine. (TNO report, p16) The fog produced by either the IC-4 or Deprox settles preferentially on horizontal, upward facing surfaces close to the machine, producing a visible film of moisture, and leaving a visible silver nitrate deposit. Other surfaces in the room remain dry. The test samples clearly were not representative of surfaces in other orientations and more distant locations. However, on the basis of this test, Deprox is claimed to disinfect “ the underneath of tables, inside lockers, the small crevices and complex equipment” (Royal Marsden Proposal 2015)
The IC-4 was unable to achieve even a log2 reduction of any pathogens on samples of ceiling tile material.


With an integrated deactivation system, the Deprox completes the entire decontamination process and subsequent deactivation with a single unit. Traditional systems either have no deactivation unit, and breakdown of the H2O2 is subject to environmental conditions, or the decontamination systems comprises two separate units, meaning twice the amount of storage, moving and handling. (Sheffield Teaching Hospitals Response to Tender, 2014)

False – A token deactivation unit was only retrofitted to Deprox in 2015. When this tender was submitted, Deprox had no deactivation system whatever and hydrogen peroxide levels at the end of the process were several times the permitted limit.


The Deprox HPV system uses patented technology to generate a vapour of hydrogen peroxide by combining high frequency ultrasonics and controlled air flow. This method allows the Deprox system to generate a vapour of hydrogen peroxide which is highly mobile within the space or room being treated and will quickly diffuse creating a homogeneous concentration of hydrogen peroxide vapour throughout the space. (Sheffield Teaching Hospitals Response to Tender, 2014)

Untrue – the TNO report clearly demonstrates that the hydrogen peroxide concentration is very inhomogeneous, with concentration in an open cupboard being only about 30% of the concentration in the centre of the room. (TNO report p26) The Deprox fog is emitted vertically with a weak airflow of only 2m3/minute which is totally inadequate to distribute the vapour around a large room.


With the real-time monitoring function of the Process Analyser, the Deprox system is intelligent as to process conditions inside the treatment area, meaning it will only display a green light on the remote Process Monitor when ambient conditions have reached levels within the EU regulatory exposure levels. (Sheffield Teaching Hospitals Response to Tender, 2014)

False – the deactivation phase is on a simple timer and will show a green light after 45 minutes regardless of the vapour levels in the room. 45 minutes is a completely inadequate time to allow for the natural breakdown of hydrogen peroxide as can be seen from the TNO report (TNO report p29) hence levels are likely to substantially exceed the 1ppm safety limit when the room is re-entered. The catalysts retrofitted to the Deprox machine following complaints from user, are contaminated by silver nitrate and dust after a number of cycles and become ineffective.


Without the need to add heat or pressure, the Deprox’s ultrasonic technology generates a vapour in a process known as “cavitation”. By vibrating the hydrogen peroxide solution at ultra-high frequencies (1.7 MHz), cavities are created within the solution, which then fill with bubbles of hydrogen peroxide vapour, rather than air. An air-flow is then created to extract these bubbles of hydrogen peroxide vapour from the solution, drawing them through a selection process to ensure that only highly mobile, highly active hydrogen peroxide vapour is introduced into the treatment environment. This leading technology is what enables the Deprox to create a 6-Log reduction of pathogens whilst only using a 4.9% hydrogen peroxide solution, and without need to add heat or pressure to the process. (Sheffield Teaching Hospitals Response to Tender, 2014)

This is completely fabricated pseudoscientific nonsense. The Deprox ultrasonic atomiser is entirely conventional, with a few piezoelectric transducer discs in the base of a shallow open topped tank, at a depth of about 50mm. The fog droplets are created at the top surface of the liquid by simple mechanical disruption, and have the same composition as the bulk liquid. The hydrogen peroxide vapour is only released when the droplets evaporate after leaving the machine.

Cavitation bubbles do form directly on the surface of the transducers, but as these are submerged under 50mm of solution, and as they individually only exist for about half of a 1.7 Mhz cycle, it is extremely hard to envisage how they could “extracted” by an “air flow”. Incidentally, this cavitation erodes pits in to the surface of the PZT (lead zirconate titanate) transducers, presumably contaminating the disinfectant solution with heavy metals.


The Deprox has on board process calibration to ensure the H2O2 levels in the environment are closely monitored throughout the treatment process.

Monitoring all influential environmental parameters, including temperature, humidity, concentrations of hydrogen peroxide and the effects of absorbent materials, the Process Analyser communicates with the Deprox’s on-board computer system to ensure that the process is effective every time, (Sheffield Teaching Hospitals Response to Tender, 2014)

..By monitoring the process outcomes, DEPROX ensures the same consistently high level of bio-decontamination irrespective of where ever, whenever, who ever. (Royal Marsden Proposal 2015)

False and dangerously misleading. There is no hydrogen peroxide sensor anywhere in the Deprox system. The Process Analyser only measures relative humidity and temperature. The system estimates the hydrogen peroxide concentration by measuring the change in relative humidity as the 5% solution is evaporated, as can be seen from the patent: . “The process works by logging the starting humidity and running the atomization unit 105 until a predetermined RH difference above the ambient is reached.” https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=20140212&DB=EPODOC&locale=en_EP&CC=GB&NR=2499819B&KC=B&ND=4

However, this is based on the false premise that the aqueous component of the Deproxin solution is the only source of water vapour in the room. The Deprox instruction manual gives the first step in the decontamination process as “Clean Room using manual cleaning methods and detergent and set up room for vaporisation process” (Royal North Shore Proposal 2012) The room is thus given a wet clean on all accessible surfaces, then the ventilation is cut off and the room is sealed. Obviously this can cause a substantial rise in humidity independently of the Deprox output. As the Process Analyser detects this rise in humidity, it will “assume” that it corresponds to a rise in hydrogen peroxide concentration and reduce the output proportionately. This makes it most improbable that the process achieves a consistent hydrogen peroxide concentration from process to process.


The Process Analyser also has an inbuilt leak detection system, which is designed to fail the process out should it detect any leaks from the treatment environment, a key safety feature for users and other personnel in the vicinity. (Sheffield Teaching Hospitals Response to Tender, 2014)

From this data the DEPROX system can detect leakage of vapour, or unexpected disturbance to the airspace being treated and adjust or terminate the process appropriately.

A dangerous falsehood. There is no leak detection system whatever. This claim is based on the fact that if the system fails to reach the target rise in humidity in 59 minutes, it will enter a fault mode. Thus if a door was left open, and the adjacent space was large and well ventilated, the machine would eventually stop vapourising. However, in the attempt to reach the target, the machine will actually output much more vapour than it would if the door was closed. Smaller leaks such as untaped door jambs or “disturbances in the airspace” are quite undetectable.


Each Deprox system can treat up to 380m3, with the ability to easily use multiple systems in tandem for larger areas, for example a whole ward can be decontaminated simultaneously. (Sheffield Teaching Hospitals Response to Tender, 2014)

See notes re the TNO report above. There is absolutely no basis to claim that Deprox can treat a volume of 380m3.


The areas that have been hard to disinfect in a room are treated to the same high standard with the DEPROX including behind the radiator, the underneath of tables, inside lockers, the small crevices and complex equipment. (Royal Marsden Proposal 2015)

False – see TNO report p.26 fig.9


When the DEPROX has completed its cycle you know you have provided a safe environment for the next patient (Royal Marsden Proposal 2015)



Studies show that with the DEPROX you can achieve a log6 reduction of both vegetative organisms Staphylococcus aureus, MRSA and spores Clostridium difficile, Bacillus subtilis. (Royal Marsden Proposal 2015)

False, this claim is based only on the TNO report, which was privately commissioned, not peer reviewed and not published in the public domain. It is also almost completely irrelevant to the Deprox system. There are no known studies, peer reviewed or otherwise that can support this claim.


Low concentration Hydrogen Peroxide vapour prevents the risk of under treatment (Royal Marsden Proposal 2015)

False –or is this a homeopathic effect?


As a family owned and managed company we are committed to five core values in our business:

Integrity- Fairness, honesty and trust will mark every relationship inside and outside of the company. (Royal Marsden Proposal 2015)

No comment needed…


Over an extended period of time, using the DEPROX, it has been proven to reduce Clostridium Difficle infections in patients by around 60%. (Royal North Shore Proposal 2012)

These claims are based on studies where a multi-component infection control “bundle” has been introduced. There is no evidence that any of the reduction is attributable specifically to Deprox. This statistic also takes no account of the fact that C. difficile rates almost halved nationally from 2010 to 2016. The national trend would have to be subtracted from any individual hospital department’s statistics in order to get a statistically meaningful result.


Reduction in environmental pathogens can be seen in the study carried out by Dr Nick Brown at Addenbrooke’s in Cambridge. (Royal North Shore Proposal 2012)

Misleading. There were in fact TWO studies relating to Deprox carried out at Addenbrooke’s by Dr Nick Brown.

The one that Hygiene Solutions are anxious to publicise relates to a “bundle” of interventions apparently including Deprox, that were implemented between 2002 and 2009.(See Addenbrooke’s Report) However, after the report was published in the Journal of Hospital Infection, a response in the form of a letter from Phillipe Destrez was published, pointing out that the hydrogen peroxide decontamination system in use at Addenbrookes in this period was actually the Glosair 400 system by Advanced Sterilization Products. Phillipe pointed out that Hygiene Solutions was only registered as a company in 2010. The Deprox trademark and patent were registered in 2012. In fact, Dr. Nick Brown gave a presentation at the Hospital Infection Society 2010 conference in Liverpool accrediting Sterinis (previous name of Glosair) as having been used at this time.

Dr Brown has some questions to answer as to why his published paper credited Deprox, where he was clearly aware that this was not the case. It may be just a coincidence that Hygiene Solutions subsequently financed what must have been a very expensive research project for Dr Brown. – see below. The email correspondence between Rick Fentiman and Nick Brown at this time is very revealing – Rick’s advice to Tom Lister, his Deprox salesman to be “aware and cautious on this one” is practically an admission of guilt.

The second report, which was sponsored by Hygiene Solutions, was published in 2013, but only in the form of a letter to Healthcare Infection, a rather obscure Australian journal.


The report summarised the results of 1840 surface contact plate samples taken from 58 rooms in Addenbrooke’s before and after the Deprox process. These showed the average efficacy of Deprox to be less than log2 – four orders of magnitude less than claimed. These results are not particularly surprising, as competing systems that work on the same principle of aerosolising a 5% solution only achieve a 2-3log kill.


The Deprox standard treatment cycle reaches 87ppm of H2O2 in the environment being treated at its process peak. This is significantly lower than traditional HPV ‘gassing’ processes. (Deprox Risk Analysis)

It it is indeed much lower than “traditional HPV”, yet apparently achieves higher log reductions. The explanation given for this paradox is that “bubbles of hydrogen peroxide” are “drawn through a selection process” so that “only highly mobile, highly active hydrogen peroxide vapour is introduced into the treatment environment” (Sheffield Teaching Hospitals Response to Tender, 2014)

The explanation given is pseudoscience. Deprox does NOT create bubbles of hydrogen peroxide. It is also NOT true that the Deprox standard treatment reaches 87ppm. The IC-4 reached this figure in the TNO tests, but the Deprox is set to give about half the hydrogen peroxide concentration of the IC-4. This is because the Deprox, even with its token catalytic deactivator, is incapable of removing these higher levels of vapour from the room within the 45 minute deactivation cycle time.


The Hydrogen Peroxide solution used in this process is Deproxin, a 4.9% Hydrogen Peroxide solution containing, 0.001% silver nitrate solution (Bolton NHS Method Statement 2014)


Hydrogen Peroxide 4.9% (a.i.)

Silver 0.2%

Distilled Water

(Deproxin bottle label)
Dangerous components:

CAS: 7722-84-1 Hydrogen Peroxide solution 2.5-10%

CAS: 7761-88-8 Silver <0.2% EINECS: 231-853-9

(Deproxin msds)

All false. Deproxin contains approximately 0.1% silver nitrate. The CAS and EINECS numbers above are for silver nitrate, not elemental silver. Silver Nitrate is toxic and caustic, and in solution will dissolve copper by a displacement reaction, hence potentially very damaging to electronic equipment.


This process is validated to deliver a 6 log reduction across a broad spectrum of organisms. (Bolton NHS Method Statement 2014)


The DEPROX bio-decontamination system vaporizes the Hydrogen Peroxide solution using high frequency ultrasonic’s. The benefit of this method is the efficient generation of vapour of a selected size to effectively defuse throughout the space and decontaminate the surfaces in the affected environment. (Bolton NHS Method Statement 2014)

Dubious, and the spelling is odd…


The DEPROX carries on board chemical indication for the purpose of the treatment cycle and designed safety features. When in routine use within the general hospital setting, as part of an enhanced cleaning programme, this would become the usual validation method unless under exceptional circumstances. (Bolton NHS Method Statement 2014)

Misleading – the only “on board chemical indication” is a humidity sensor. Hygiene Solutions claims: “After every process we run, we provide validation so that you can make informed decisions about the patient environment. Every callout will receive a report on the decon processes carried out and comprehensive validation.” http://hygiene-solutions.co.uk/on-call-decon/ It seems that that the “usual validation method” is based on RH readings, which are very unlikely to be representative of the level of decontamination achieved.


When decontaminating a room in preparation for the next patient, it is essential to deliver the highest log reduction available in order to thoroughly decontaminate the environment. This is fundamental in reducing hospital acquired infections. (Deprox Comparative Analysis)

True…but misleading. Deprox does not give the highest log reduction available.


The Deprox system uses ultrasonic technology to create the vapour. By introducing an ultra-fine vapour, the Deprox is able to achieve optimum levels of decontamination whilst using only very low concentrations of chemical. (Deprox Comparative Analysis)

There is no reason why an “ultra-fine” vapour enables the use of “very low concentrations” Deprox in any case does not achieve “optimum levels of decontamination.”


The Deprox offers the best combination of efficacy and efficiency available on the market today.


False. There are pressurised aerosol based devices that offer higher efficacy at much lower cost.


The Deprox system itself has been designed with safety at the centre of all design features. (Sheffield Teaching Hospitals Response to Tender, 2014)



Hygiene Solutions believe in evidence. (Royal Marsden Proposal 2015)

Not much evidence of this…


Hygiene Solutions believe Health & Safety of our equipment and systems is extremely important to ensure the safety of our operators, staff, patients and visitors is not compromised. (Sheffield Teaching Hospitals Response to Tender, 2014)

This belief does not seem to translate in to action.


This Tender is made in good faith, and is intended to be genuinely competitive;

I have read and I understand the contents of this Certificate, and I understand that knowingly making a false declaration on this form may result in legal action being taken against me. (Sheffield Teaching Hospitals Response to Tender, 2014)

It may well do…