HOCl Trust for Hygiene and Safer Water
Open Letters to the NHS

Throught the SARS-CoV-2 pandemic, we worked hard to bring the benefits of HOCl to the attention of the NHS' Procurement, Re-Use and Improvement Teams.

When the country locked down on 23rd March 2020, we immediately recognised the need for HOCl to be provided to frontline keyworkers as part of their own Personal Protective Equipment (PPE), together with the standard PPE we have all come to recognise as being in high demand and short supply.

While we have been busily focussed on getting PPE to those 'on the ground', our supporters started working doggedly on securing the attention of people 'at the top' to raise awareness more specifically of the urgent role HOCl could play in managing infection rates in hospitals through fogging.

As a result of one particular man's tireless efforts, The Hon. Richard Arthur, HOCl has now been brought to the attention of NHS Reuse and Improvement Teams (who have since been in communication with us) and millions of people through Mark Palmer's article in the Daily Mail. For his extraordinary support, we would like to recognise Richard publicly, and thank him. Hopefully our combined efforts will not be wasted and decision-makers will now take HOCl seriously, but as a very small charity with limited resources and being run by volunteers we could not have got this far without Richard's help.

We are also indebted to Dr. Hugh Martin BSc (London), MSc (Imperial), PhD (London), DIC Royal Agricultural College, for his seemlingly unending scientific advice, guidance, unwaning support and calming manner!

We are posting letters below for your interest and use. To date we are yet to hear back from NHS Re-Use regarding acceptable protocols for testing HOCl on PPE for potential reuse. We have offered to commission the testing to speed things up; we are also awaiting further communication from NHS Improvement to see if they will be implementing the sustainable use of HOCl throughout the NHS.

Open Letters from HOCl Trust to the NHS

Letter 3rd June 2020 to NHS Re-Use Team

PLEASE NOTE: The HOCl Trust for Hygiene and Safer Water has no commercial interests in the promotion of the use of HOCl, and has no commercial ties with any of the companies or brands referenced in this document.

A Comprehensive Look at the Use of Hypochlorous Acid for the Hospital Setting During Covid-19 Outbreak

Who is the HOCl Trust?

The HOCl Trust for Hygiene and Safer Water comprises three volunteer Trustees dedicated to informing and educating about Hypochlorous Acid (HOCl). We are a charity and not a commercial entity. During the Covid-19 outbreak, our focus has been on providing free supplies of HOCl to frontline key workers ‘on the ground’ with guidance on how to use it to protect themselves, their patients and their families and co-workers from infection. Our wider effort has been to attempt to encourage the government via various contacts such as Hon. Richard Arthur, whom you spoke with today, to implement a programme of fogging in hospitals and to encourage the use of HOCl as keyworkers’ PPE.

What is Hypochlorous Acid?
Hypochlorous Acid (HOCl) is part of the immune system, made by our white blood cells to kill pathogens when invading the body1. HOCl is safe and non-toxic, it is used in a variety of applications from open abdominal wound cleaning2 to gargling for sore throats3,4, nasal irrigation5 from the food industry6 and agriculture7 to sterilising baby equipment8, no rinsing is required, it can be touched and even drinking it causes no harm9,10.

How is HOCl made?
There are several ways of making HOCl outside of the body. Many commercial manufacturers use electrolysis of saline solution (such as our founder’s original product, ‘Sterliox’). We have determined a method of making HOCl chemically which is far more cost effective, stable and easier to transport (Salvox – see Unilever presentation pdf attached). We then determined that NaDCC is HOCl on dissolution – an easy and readily available form of free available chlorine which is stable and produces HOCl at the perfect pH when dissolved in water to the correct concentration (see PURTABS brochure pdf, and Angiene SDS pdf).

HOCl in the NHS

Key Facts:
• The W.H.O. have HOCl in the form of Chlorine: ‘NaDCC’ listed on their Disease Commodity Package for Novel Coronavirus as critical PPE for health care facilities11.
• NaDCC (sodium dichloroisocyanurate otherwise known as troclosene sodium12) when dissolved in water is free available chlorine in the form of Hypochlorous Acid (HOCl)13.
• NaDCC is available to the NHS in tablet form in the NHS Supply chain catalogue14 e.g.:
o Terralin Chlorine Tablet (schülke UK)15 MPC: 10010 MRB1210
o SoChlor TAB GV (Health Ltd)16 MPC: S325TB200 MFB254

HOCl - "...the gold standard by which all antiviral, antibacterial and sporicidal agents must now be compared.”
Dr. Joe Selkon, MBChB, FRCPath, DCP. Formerly Consultant Microbiologist, Oxford University John Radcliffe Hospital 10th March 2010

There are several brands and suppliers on the list – main ingredient must be sodium dochloroisocyanurate or trocolosene sodium, additional ingredients may be adipic acid and sodium carbonate, but these do not inhibit the manufacture of HOCl on dissolution.

• NaDCC tablets are made available by NHS’ Dedicated PPE Supply Channel for Covid-19 all NHS Trusts as ‘Chlorine releasing tablets’17 HOWEVER all products on the list as ‘General Purpose Detergent’ contain detergents which prevent the product from being made up as safe HOCl.

• Staff have been told they aren’t allowed to use the NaDCC we are donating to them, as it is not alcohol-based, or it is not the product they have trained their staff to use and they don’t have the time to retrain their staff and therefore are not using the supplies they have registered for.

The added detergent means that the NaDCC cannot be used to its full potential as HOCl, that is:
➢ used to decontaminate PPE during the donning and doffing stage (all reusable PPE could be easily decontaminated with HOCl, and even single use PPE could be decontaminated where there is a shortage, although due to the ‘flimsy’ nature of this type of single use PPE it could be impractical, but a simple fog or spray down whilst in sue will prolong the life of the PPE)

➢ used topically on hands, sprayed on the face, as a gargle or used as a nasal rinse if concern of contamination with Covid-19 is suspected and carried as PPE

➢ fogged or misted safely around people in tunnels or dedicated fogging spaces on entrances/exits into and out of hospitals

An increasing number of organisations globally are using HOCl for fogging to combat Covid-19 in a variety of settings from hospitals to dental surgeries, care homes and for fogging of entrances to public transport and places of work, even the fire departments in the US are using it to fog their fire engines. It is safe for fogging in the presence of people18 (and see HOCL Mist Paper pdf attached).

HOCl is widely recognised to deal swiftly with viruses, for example, when fogged, only 20ppm can kill norovirus in up to 10 mins. 200ppm kills norovirus in up to a minute19.

With greater understanding of the chemistry NHS supply chain has access to, it can be quick and easy to move away from the detergent-contaminated product to the NaDCC without detergents, namely, from GV Health for example, MFB254, MFB255, MFB637, MFB694 SoChlor TAB20 will all make safe, cost-effective, superiorly efficient biocide for managing healthcare facilities.

The NHS Supply Chain, with this knowledge, has a duty to urgently:

• Shift to the detergent-free NaDCC products from suppliers
• Upgrade NaDCC to ‘Essential PPE for frontline staff’
• Launch an NHS-wide information-based campaign to educate staff about the properties of HOCl and how to make it easily with the NaDCC they have made available to them through the supply channel
• Break away from the restrictive protocol of using fogging in hospitals only when the hospital is considered to be the original source of infection during this outbreak and implement fogging at doffing stations at the very least, but ideally at hospital entrances and exits to minimise any viral contamination on the person of anyone going into or out of a hospital
• Announce to all frontline keyworkers that if they are given/donated or provided with chlorine disinfectant tablets or granules they can and should use them as directed on the package, to make up 1000ppm, in place of alcohol-based rubs where these are unavailable or in short supply

With access to their own hand-held HOCl sprays, frontline staff could frequently decontaminate themselves with 500-1000ppm, without harming themselves, their colleagues or their patients. If hospitals had supply of NaDCC to hand that wasn’t contaminated with detergents, fogging in hospitals could be widely implemented quickly and cost-effectively, rapidly reducing the risk to life of both staff and patients, and reducing the risk of taking the virus home with them to their families.

Two articles which highlight the benefits of HOCl for the NHS and in the battle against Covid-19 note:
Hypochlorous Acid in the Fight Against COVID-19, Alan G. Kabat, OD, FAAO
Why the NHS and Private Clinics Should Look Further than Alcohol-Based Sanitisers

YouTube Playlists of interest:

How to make HOCl
500ppm AFC: 1 x 1.7g NaDCC tablet to 2 litres water.
1000ppm AFC: 2 x 1.7g NaDCC tablets to 2 litres water.
2000ppm AFC: 4 x 1.7g NaDCC tablets to 2 litres of tap water.

1) https://en.wikipedia.org/wiki/Hypochlorous_acid
2) https://www.woundsresearch.com/article/intraabdominal-lavage-hypochlorous-acid-new-paradigm-septic-and-open-abdomen
3) this study shows how gargling with salt water works to generate HOCl in the cells http://www.elvisstudy.com/nasal-irrigation-and-gargling.html
4) gargling directly with HOCl works also https://www.alliedacademies.org/articles/comparison-of-the-preventive-effects-of-slightly-acidic-hocl-mouthwash-and-chx-mouthwash-for-oral-diseases.pdf
5) https://onlinelibrary.wiley.com/doi/abs/10.1097/MLG.0b013e31817f4d34
6) https://www.hypochlorousacid.com/research-foodindustry?industry=Food
7) https://www.hypochlorousacid.com/research-industry-display?industry=Agriculture&application=All
8) https://www.boots.com/vital-baby-aquaint-sanitising-water-500ml-10199504 / https://www.vitalbaby.com/aquaint-sanitising-water-packs/
9) https://holisticdentistryusa.com/can-you-drink-hypochlorous-acid/
10) https://www.unicef.org/cholera/Annexes/Supporting_Resources/Annex_9/Clasen-NaDCC2.pdf
11) https://www.who.int/emergencies/what-we-do/prevention-readiness/disease-commodity-packages/dcp-ncov.pdf?ua=1 (also attached)
12) https://en.wikipedia.org/wiki/Sodium_dichloroisocyanurate
13) https://www.who.int/water_sanitation_health/dwq/chemicals/sodiumdichloroisocyanuratesum_2nadd.pdf (also attached)
14) https://my.supplychain.nhs.uk/Catalogue/search?query=chlorine
15) https://media.supplychain.nhs.uk/media/documents/MRB1210/COSHH/70718_MRB1210.pdf
16) https://my.supplychain.nhs.uk/Catalogue/product/mfb254
17) https://www.ppe-dedicated-supply-channel.co.uk/ppe-product-listing/
18) https://www.aqualution.co.uk/2020/02/05/novel-coronavirus-2019-ncov-aqualution-effective-prevention-and-control/
19) https://aem.asm.org/content/73/14/4463
20) https://www.gvhealth.com/en/hygiene-solutions/sochlor/sochlor-tabs.html

Email to NHS Procurement Team: 8th June 2020

We are indeed aware you have both products listed on the general NHS supply channel, however it’s the dedicated Covid-19 PPE channel that the non-detergent containing supply should also be listed on urgently, that is our concern, and categorised as PPE Hand Hygiene (https://www.belle.org.uk/news-1/2020/4/2/why-the-nhs-and-private-clinics-should-look-to-hypochlorous-acid-rather-than-alcohol-based-sanitisers), and acknowledged as safe for use in the presence of people and topically. Without this step, frontline keyworkers and Trusts are unaware they are able to use it in this way.


“I am a key worker, I’ve suffered from severe contact dermatitis since COVID-19 came around. My hands have been sore, bleeding and scaly. The other week my employer provided another alcohol sanitiser, I dripped some accidentally on top of a painted metal cabinet- it stripped the paint instantly. I was lucky enough to find @dew_products in Dundee and subsequently yourselves through doing research. I have since been exclusively using @dew_products cleaner HCOL based and their sanitiser to wash my hands. Within a week my hands are healed and in better condition than they have for years. I have also been carrying some along with me cleaning my desk area etc and my sinuses also feel loads better." (source: https://www.instagram.com/p/B_zfADEHpIV/?utm_source=ig_web_copy_link)


I would welcome a meeting, however people are not adequately protected now; people are dying now, so now is the time for action. Please see attached my recent letter to NHS ENGLAND & NHS IMPROVEMENT, as well as further information regarding the fogging or HOCl, which NHS Truts should consider implementing right away with Chorine releasing Tablets, in order to move safely into Phase two of the Operating Framework.. - HOCl is non-toxic and non-corrosive and safe to be fogged 24/7 in the presence of people with and without PPE, therefore there needs to be no ‘downtime’ while areas are being fogged/decontaminated, which will speed up the reintroduction of other services within the hospital and help the hospital manage phase 2 without endangering health.


Please see these posts from University of West of England: They have been making HOCl and supplying it to frontline keyworkers including Nightingale Hospital Bristol https://info.uwe.ac.uk/news/UWENews/news.aspx?id=4025


“As well as being used as a surface disinfectant, the UWE Bristol disinfectant could play a role in tackling the UK’s shortage of personal protective equipment (PPE) for medical staff. It can be used to spray down some PPE for decontamination and safe reuse as well as disinfect the inside of ambulances. This approach is being tested with industrial partners at an independent laboratory ahead of possible introduction to the front line.”


“Unlike commonly used disinfectants such as bleach, the cleaning product made at UWE Bristol is called electrochemically activated solution (ECAS). ECAS technology can provide resilience to frontline sectors when supply chains struggle.”


ECAS disinfectant IS HOCl – the same disinfectant as is made by NaDCC (Chlorine releasing) tablets.




For more information:





Letter to NHS Re-Use Team 17th June 2020


Human Coronavirus Strain 229E - “AX250 demonstrated a 99.994% reduction in the stock virus titer as compared to the titer of the corresponding virus control. The log reduction in viral titer was 4.25 log10” (1)

“The recommendation of 0.1% (1000 ppm) in the context of COVID-19 is a conservative concentration that will inactivate the vast majority of other pathogens that may be present in the health-care setting.” (2)

“…hypochlorous acid and hypochlorite ions promote amino acid degradation and hydration, what corroborates with the mechanism of action performed by WHO (2016), when affirming that chlorine compounds lead to inhibit actions enzymes, protein denaturation and inactivation of nucleic acids and, therefore, it is recommended as a disinfectant agent for the prevention and control of pandemics related to respiratory infections, such as COVID-19.” (3)

“Sterilox HG or 10% household bleach resulted in a 5 log10 or greater CFU reduction of C. difficile spores, VRE, and MRSA in 10 minutes” (4)

“We conclude that HOCl solution as a liquid or fog is likely to be effective in disinfecting common settings to reduce NV exposures and thereby control virus spread via fomites.” (5)

“Within the framework of the results of our study, we believe that electrolyzed water can be regarded as a cost-effective disinfectant that is successful in controlling hospital infections, as it had an effect on bacteria showing various resistance patterns.” (6)

Sodium dichloroisocyanurate (NaDCC tablet): Hep A, Hep B, Porcine Epidemic Diarrhea virus (PEDs), Influenza Virus H1N1, Norovirus (7)

“NaDCC is an alternative source of FAC (HOCl). Accordingly, the significant body of evidence on the antimicrobial action of chlorine is as relevant to NaDCC as it is to NaOCl and other sources of chlorine... Susceptibility to hypochlorous acid has been established with respect to a wide variety of bacteria, including Escherichia coli, Salmonella dysenteriae, Shigella sonnei, Campylobacter jejuni, Yersinia enterocolitica; viruses, including hepatitis A, poliovirus (type 1), rotavirus, adenovirus and calicivirus; helminthes; and protozoa, including cysts of Entamoeba histolytica and Giardia lamblia.” (7)


1. Virucidal Efficacy Data for Aquaox Solution
2. World Health Organisation Interim guidance 15 May 2020: Cleaning and disinfection of environmental surfaces in the context of COVID-19 https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjXvJHh94fqAhUBJBoKHRc3D-MQFjABegQIARAB&url=https%3A%2F%2Fapps.who.int%2Firis%2Frest%2Fbitstreams%2F1277966%2Fretrieve&usg=AOvVaw3WAUbtcQd3p2JAF_7EMWNS
3. Use of chlorine solutions as disinfectant agents in health units to contain the spread of COVID-19. J. Health Biol Sci. 2020;8(1):1-9 Frank Pereira de Andrade, Camila de Bessa Pereira https://periodicos.unichristus.edu.br/jhbs/article/view/3256 22
4. Effectiveness of an Electrochemically Activated Saline Solution for Disinfection of Hospital Equipment. Infection Control and Hospital Epidemiology May 2013, Vol. 34, No. 5. Dennis Fertelli;1 Jennifer L. Cadnum, BS; Michelle M. Nerandzic, BS; Brett Sitzlar, BS; Sirisha Kundrapu, MD; Curtis J. Donskey, MD. https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/div-classtitleeffectiveness-of-an-electrochemically-activated-saline-solution-for-disinfection-of-hospital-equipmentdiv/06EF3797AEC4BA1A2A0347AB494F5C7E
5. Evaluation of Liquid- and Fog-Based Application of Sterilox Hypochlorous Acid Solution for Surface Inactivation of Human Norovirus. Geun Woo Park, Deyanna M. Boston, Julie A. Kase, Mark N. Sampson, and Mark D. Sobsey https://aem.asm.org/content/73/14/4463
6. An investigation into the in-vitro effectiveness of electrolyzed water against various microorganisms. Int J Clin Exp Med 2015;8(7):11463-11469. Keramettin Yanik1, Adil Karadag1, Nevzat Unal2, Hakan Odabasi1, Saban Esen3, Murat Gunaydin https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4565347/pdf/ijcem0008-11463.pdf
7. COVID-19 | Coronavirus Report: 2020-03-09: Surface Disinfection Methods. The Infection Prevention Strategy. https://infectioncontrol.tips/wp/wp-content/uploads/2020/01/2019nCoV-Surface-Disinfection-Methods.pdf
8. Sodium dichloroisocyanurate (NaDCC) tablets as an alternative to sodium hypochlorite for the routine treatment of drinking water at the household level. Int. J. Hyg. Environ.-Health 209 (2006) 173–181 Thomas Clasen, Paul Edmondson. https://www.unicef.org/cholera/Annexes/Supporting_Resources/Annex_9/Clasen-NaDCC2.pdf


Due to a compatible pH with human skin, and the fact that Hypochlorous acid is made by the human immune system to fight pathogens and is non-cytotoxic, HOCl can be safely fogged in the presence of people (1) and topically applied to skin and is used for wound disinfection and accelerated healing (2, 8) as well as used for the treatment of eyelids (3), as a nasal rinse (4), therefore at all recommended concentrations of HOCl are always at a safe level, and re-donning can be immediate once PPE has dried.

“Topical stabilized HOCl provides an optimal wound healing environment and, when combined with silicone, may be ideal for reducing scarring. Additionally, in contrast to chlorhexidine, HOCl, used as an antiseptic skin preparation, raises no concerns of ocular- or ototoxicity.” (5)

“We speculate that some ocular spray disinfectants that contain hypochlorous acid, usually applied to treat blepharitis in order to reduce bacterial and viral load on the skin and eye lashes, could be used as a measurement of prevention for the facial area where many other chemical agents cannot be applied.” (6)

“HOCl has been incorporated into topical formulations due to antimicrobial, anti-inflammatory, immunomodulatory, and wound healing properties…Topical formulations of stabilized, pH-neutral HOCl (e.g., solution, gel, spray) have been evaluated in several studies demonstrating both antimicrobial effects and therapeutic benefit in many cutaneous disorders, including seborrheic dermatitis, atopic dermatitis-associated pruritus, acne vulgaris, diabetic foot ulcers, and hypertrophic scars/keloids. Topical HOCl appears to be well tolerated and safe, without any major adverse events reported.” (7)

1. Studies on Air-Borne Virus Infections in The Killing of Aerial Suspensions of Influenzavirus By Hypchlorous Acid By D. G. Ff. Edward And O. M. Lidwell, From the National Institute for Medical Research, London, N.W. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/FED980BCC43BD8CD785AA70C05115496/S002217240001281Xa.pdf
2. Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures https://www.patrickbitterjrmd.com/wp-content/uploads/sites/122/2020/01/Topical_Stabilized...hYPOCHLOSOUS_ACID_Article_Publ_Jan_2020.pdf
3. The application of a saline hygiene solution preserved with pure HOCl acid reduced the bacterial load significantly without altering the diversity of bacterial species remaining on the skin under the lower eyelid.
Clinical Ophthalmology 13_04_2017 David W Stroman, Keri Mintun, Arthur B Epstein, Crystal M Brimer, Chirag RPatel, James D Branch, Kathryn Najafi-Tagol
4. Effects of a Low Concentration Hypochlorous Acid Nasal Irrigation Solution on Bacteria, Fungi, and Virus. The Laryngoscope 02 January 2009 Hyun Jik Kim MD, Jeung‐Gweon Lee MD, Ju Wan Kang MD, Hyung‐Ju Cho MD, Hyun Su Kim MD, Hyung Kwon Byeon MD, Joo‐Heon Yoon MD
5. Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures. Michael H. Gold MD, FAAD, Anneke Andriessen PhD, Ashish C. Bhatia MD, FAAD, Patrick Bitter Jr MD, FAAD, Suneel Chilukuri MD, FAAD, FACMS, Joel L. Cohen MD, FAAD, FACMS, Chris W. Robb MD, PhD.
6. COVID-19 Disease and Ophthalmology: An Update Received: April 28, 2020 .Mari´a A. Amesty Jorge L. Alio´ del Barrio Jorge L. Ali https://link.springer.com/content/pdf/10.1007/s40123-020-00260-y.pdf
7. Status Report on Topical Hypochlorous Acid: Clinical Relevance of Specific Formulations, Potential Modes of Action, and Study Outcomes by JAMES Q. DEL ROSSO, DO and NEAL BHATIA, MD. J Clin Aesthet Dermatol. 2018;11(11):36-39 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303114/
8. The Use of Hypochlorous Acid Lavage to Treat Infected Cavity Wounds . Wongkietkachorn, Apinut MD*; Surakunprapha, Palakorn MD†; Wittayapairoch, Jakrapan MD‡; Wongkietkachorn, Nuttapone MD§; Wongkietkachorn, Supawich MD Plastic and Reconstructive Surgery - Global Open: January 2020 - Volume 8 - Issue 1 - p e2604



“Due to the neutral pH of the HOCL, it is non-toxic, does not leave residue on environmental surfaces, and is not corrosive to hospital equipment as traditional bleach and phenolics have long demonstrated.” (1)

Electrolytically-produced HOCL has been used for many years to process endoscopy units without causing significant corrosive concern that would have a bearing on the processes we are proposing for the use of NaDCC-derived HOCl for PPE. (2)

“The material compatibility of the Sterilox germicide (HOCl) was evaluated by subjecting a variety of metallic, plastic, adhesive and rubber endoscope components to continuous immersion in Sterilox. The samples were inspected for, visible change, visible evidence of damage or any other change in appearance. Sterilox germicide does not produce any corrosion or other visible damage in the majority of endoscope components. Color changes and the "tack"* of the coating of the outer endoscope sheaths were noted on some endoscopes. Corrosion was noted on anodized aluminum*.” (2)

*These issues were not considered relevant by Essex Rivers Healthcare NHS Trust when weighed up against the benefits of the use of Sterilox in place of glutaraldehyde for sterilising endoscopes. Also, this was resulting from continuous immersion in Sterliox. This is not the process that we are proposing for HOCl for PPE in a hospital setting.

1. Hypochlorous Acid for Definitive Terminal Cleaning of the Hospital Environment https://www.infectioncontroltoday.com/environmental-hygiene/hypochlorous-acid-definitive-terminal-cleaning-hospital-environment By Dorris Dimmit, MPH, CIC
2. Sterilox Liquid Chemical High Level Disinfectant System Safety Data Sheet https://www.accessdata.fda.gov/cdrh_docs/pdf/k013280.pdf



Electrolytically-produced HOCL has been used for many years to process endoscopy units without corrosive concern, despite being submerged for long periods of time in solution. (1)

We are unable to locate tests evidencing use of NaDCC-generated HOCl on common PPE materials, however we have found references to testing on metals. (2)

“Electrochemically activated saline solutions …are commonly used for disinfection of dental equipment and endoscopes, , and swimming pool sanitation.” (3)

“This ECA process produces a powerful “free available chlorine (FAC)” sterilising and disinfection liquid – Anolyte ANK – at a concentration of 500–700ppm, within a neutral pH range of 6–7.5, making it ideal for use on equipment and surfaces within a cleanroom, for example.” (4)

We are unable to find any references to degradation of materials or plastics after fogging or spraying of HOCl.

1. Finding an alternative endoscope disinfectant to glutaraldehyde https://www.nursingtimes.net/archive/finding-an-alternative-endoscope-disinfectant-to-glutaraldehyde-01-02-2004/
2. Angiene NaDCC SDS http://medi-mark.co.uk/images/uploads/ANIGENE_NaDCC_Detailer_with_Technical_Details_and_MSDS.pdf
3. Effectiveness of an Electrochemically Activated Saline Solution for Disinfection of Hospital Equipment of Hospital Equipment. Infection Control & Hospital Epidemiology Dennis Fertelli, Jennifer L. Cadnum, Michelle M. Nerandzic, Brett Sitzlar https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/div-classtitleeffectiveness-of-an-electrochemically-activated-saline-solution-for-disinfection-of-hospital-equipmentdiv/06EF3797AEC4BA1A2A0347AB494F5C7E
4. Electrolysed water solutions as a disinfection option https://www.cleanroomtechnology.com/news/article_page/Electrolysed_water_solutions_as_a_disinfection_option/133457


There is no reason to believe that fogging/misting with HOCl will compromise the fit of a respirator in any way, even after repeated cycles.


Hypochlorous acid is made by the human immune system and does not pose any dangers either when in topical contact or when inhaled, or consumed in drinking water (1).


Hypochlorous acid is non-toxic and non-cytotoxic, can be safely fogged in the presence of people (2) and topically applied to skin (3) as well as used for the treatment of eyelids, as a nasal rinse (4) is used for wound disinfection (5).


“Toxicological Conclusion:

For all practical purposes the health risks to patient and to operator arising from exposure to Sterilox germicide and diluted Sterilox germicide are minimal. The principal potential effect of the chemicals present in Sterilox would be irritation, but Sterilox does not exhibit this effect in tests. Sterilox is unlikely to pose a significant risk to either patient or user.” (6)


“Application of Sterilox HG did not result in production of noticeable noxious fumes but was described as producing an odor similar to that of swimming pool water. There were no reported complaints from nursing staff or patients." (7)


“All chlorine products have some level of toxicity; this is what renders them such effective microbicides. When chlorinated water is ingested, however, the available chlorine is rapidly reduced by saliva and stomach fluid to harmless chloride ions salts (Kotiaho et al., 1992). This is true for all sources of chlorine, including both NaOCl and NaDCC… Chronic and sub-chronic toxicity studies also found no toxicity. Developmental toxicity studies have also established that the compound is not fetotoxic, teratogenic (causing birth defects), mutagenic or carcinogenic. Chlorinated isocyanurates are not metabolized in the body and do not bioaccumulate.” (8)


1. World Health Organization Guidelines for Drinking-Water Quality, 3rd edition including 1st and 2nd addenda, 2008 https://www.who.int/water_sanitation_health/dwq/chemicals/sodiumdichloroisocyanuratesum_2nadd.pdf

2. STUDIES ON AIR-BORNE VIRUS INFECTIONS In THE KILLING OF AERIAL SUSPENSIONS OF INFLUENZAVIRUS BY HYP0CHLOR0US ACID BY D. G. Ff. EDWARD AND 0. M. LIDWELL, From the National Institute for Medical Research, London, N.W. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/FED980BCC43BD8CD785AA70C05115496/S002217240001281Xa.pdf/studies_on_airborne_virus_infections_iii_the_killing_of_aerial_suspensions_of_influenza_virus_by_hypochlorous_acid.pdf

3. Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures https://www.patrickbitterjrmd.com/wp-content/uploads/sites/122/2020/01/Topical_Stabilized...hYPOCHLOSOUS_ACID_Article_Publ_Jan_2020.pdf

4. Effects of a Low Concentration Hypochlorous Acid Nasal Irrigation Solution on Bacteria, Fungi, and Virus. The Laryngoscope 02 January 2009 Hyun Jik Kim MD, Jeung‐Gweon Lee MD, Ju Wan Kang MD, Hyung‐Ju Cho MD, Hyun Su Kim MD, Hyung Kwon Byeon MD, Joo‐Heon Yoon MD https://onlinelibrary.wiley.com/doi/abs/10.1097/MLG.0b013e31817f4d34

5. Intraabdominal Lavage of Hypochlorous Acid: A New Paradigm for the Septic and Open Abdomen Luis G Fernández, Marc R. Matthews, Lawton Seal  Wounds 2020;32(4):107–114. Epub 2020 January 23 https://www.woundsresearch.com/article/intraabdominal-lavage-hypochlorous-acid-new-paradigm-septic-and-open-abdomen

6. Sterilox Liquid Chemical High Level Disinfectant System Safety Data Sheet https://www.accessdata.fda.gov/cdrh_docs/pdf/k013280.pdf

7. Effectiveness of an Electrochemically Activated Saline Solution for Disinfection of Hospital Equipment INFECTION CONTROL AND HOSPITAL EPIDEMIOLOGY MAY 2013, VOL. 34, NO. 5 https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/div-classtitleeffectiveness-of-an-electrochemically-activated-saline-solution-for-disinfection-of-hospital-equipmentdiv/06EF3797AEC4BA1A2A0347AB494F5C7E Dennis Fertelli;1 Jennifer L. Cadnum, BS; Michelle M. Nerandzic, BS; Brett Sitzlar, BS; Sirisha Kundrapu, MD; Curtis J. Donskey, MD.

8. Sodium dichloroisocyanurate (NaDCC) tablets as an alternative to sodium hypochlorite for the routine treatment of drinking water at the household level. Int. J. Hyg. Environ.-Health 209 (2006) 173–181 Thomas Clasen, Paul Edmondson. https://www.unicef.org/cholera/Annexes/Supporting_Resources/Annex_9/Clasen-NaDCC2.pdf


Hypochlorous Acid (HOCl) is already recommended for Covid-19 infection prevention and control by PHE as ‘1000ppm available chlorine’, and is considered suitable for use at this concentration in the presence of patients in the room .

Hypochlorous acid is ‘available free chlorine’ and can be made with electrolytically-activated saline solution, or chemically using NaDCC (troclosene sodium / sodium dichloroisocyanurate) tablets.

HOCl is available already on the NHS Dedicated PPE Supply Channel from suppliers GV Health, Diversey and Guest Medical (just don’t get the one with detergent in!)

Common Names for Hypochlorous Acid Solutions:

  • Electrolytically Generated Hypochlorous Acid
  • Neutral Electrolyzed Water (NEW)
  • Electrolyzed Oxidizing Water (EOW)
  • Electro-chemically Activated Water (ECA)
  • Super-oxidized water (SOW)

For the purpose of clarification, the brands ‘Aquaox’, ‘Sterilox’ and ‘Aqualution’ as cited in the letter and references, are brand names for Electrolytically Generated Hypochlorous Acid. There is no one supplier.