Chemical Fogging In Schools And Buses Considered Harmless

Published: Wednesday, 21 October 2020 on Written by Connor Gerbrandt

While the term “fogging” may typically be used in reference to repelling mosquitoes or other insects, an entirely different kind of fogging is happening in local schools and officials report that it is entirely harmless to humans.

Peters says this is the fogging machine used in schools on a weekly basis (supplied by HSD). ‘Rochester Midland Enviro Care Neutral Disinfectant-No Fragrance’ is the hefty title given to the chemical now being used daily by the Hanover School Division. Assistant Superintendent Leanne Peters says the odorless product is sprayed throughout each school building once a week during the night.

“The fogging happens in conjunction with our ventilation systems,” she notes. “We are opening our vents at night so that we are moving more fresh air through our schools at the same time we are fogging.”

Once applied to a surface, the product’s dry time is ten minutes during which it kills any harmful bacteria including the COVID-19 virus.

“If there were to be a positive case we would ask the fogging person to come and give that school an additional cleaning,” she offers. “The main thing is that we want our staff and students to be safe in our schools.”

Peters indicates that a small number of parents have called the division office concerned about the unfamiliar chemical and what side effects it could cause. In those situations, she says explaining the fogging process and providing the full Material Safety Data Sheet has usually been enough to calm their nerves.

According to the manufacturer, Rochester Midland Corporation, the chemical is the same sort of compound being used in hospitals, nursing homes, and veterinary clinics across North America. The product is also approved for use in schools by Health Canada. Peters says that too should give worried parents a level of solace. 

On school buses, a similar array of sanitizing products are used on an almost hourly basis. Chief among the bus drivers’ arsenal is a product known as didecyldimethylammonium chloride.

“I’m a bus guy, so that is a really big word for me,” laughs Transportation Director Robert Warkentin after several attempts to pronounce it.

The solvent container has a description plastered across it which indicates that it is not harmful to humans, animals, plants, or marine life, that no protective equipment is necessary for its use, and that there are no known side effects related to its dispersal.

Where schools are fogged once a week, among other more regular sanitizing procedures, Warkentin says his buses are sprayed between every single use.


A very simple but informative chart to help you chose the right disinfectant. Sani Pass uses HOCl Anolyt exclusively for all its disinfection units… this means great disinfection results but no health or environmental risks. Tough on the germs but soft on humans and the environment.

Disinfecting machine invented to help get crowds back at venues amid pandemic

By: Chris Conte for Rebound Colorado

From football stadiums to movie theatres, the idea of large crowds is still terrifying to a lot of people during this pandemic, but a new invention that helps kill COVID-19 germs instantly could help get people back into some of the nation’s most beloved large venues.

For Mark Zurevinski, who once traveled the globe managing shows for superstars, business disappeared in an instant this past spring. With both his employees and his own livelihood on the line, Zurevinski looked around at all those stadiums and decided to come up with a solution to help get people safely back into large spaces.

“I saw everyone in the entertainment crossing their arms and waiting for the government to find a solution,” he said.

In the middle of the pandemic, as businesses worldwide shut down, Zurevinski started a new business called Sani Pass.

The company has developed a disinfecting channel walkthrough machine to kill the novel coronavirus. First, the machine takes your temperature, then nozzles spray a fine non-toxic disinfecting solution over your clothes and bags that kill any COVID germs you may have on you.

One machine costs around $12,000.

“We’re not suggesting we’re a cure. We’re suggesting we are a part of a broader arsenal of products that need to be implemented in order to bring us back to some form of normalcy,” Zurevinski added.

Zurevinski also knew that if you couldn’t move people through the machine quickly, it wouldn’t matter.

It takes about eight seconds for one person to get a person disinfected in the Sani Pass. The company estimates they could get 55,000 people into a stadium in just 90 minutes.

“I wanted to get people back into arena, back into theatres, back into stadiums. Those are large mass gatherings and in order to get people in there quick enough, we had to find a solution that was not 30 seconds, one minute, two minutes each,” he said.

Aside from stadiums, Zurevinski is also in talks with some airports who are considering putting the Sani Pass in place.

Hypochlorous Acid: An Ideal Wound Care Agent With Powerful Microbicidal, Antibiofilm, and Wound Healing Potency, December 2014

Abstract: Chronic wounds and the infections associated with them are responsible for a considerable escalation in morbidity and the cost of health care. Infection and cellular activation and the relation between cells are 2 critical factors in wound healing. Since chronic wounds offer ideal conditions for infection and biofilm production, good wound care strategies are critical for wound healing. Topical antiseptics in chronic wounds remain in widespread use today. These antiseptics are successful in microbial eradication, but their cytotoxcity is a controversial issue in wound healing. Objective. The aim of this study was to investigate the effect of stabilized hypochlorous acid solution (HOCl) on killing rate, biofilm formation, antimicrobial activity within biofilm against frequently isolated microorganisms and migration rate of wounded fibroblasts and keratinocytes. Materials and Methods. Minimal bactericidal concentration of stabilized HOCl solution for all standard microorganisms was 1/64 dilution and for clinical isolates it ranged from 1/32 to 1/64 dilutions. Results. All microorganisms were killed within 0 minutes and accurate killing time was 12 seconds. The effective dose for biofilm impairment for standard microorganisms and clinical isolates ranged from 1/32 to 1/16. Microbicidal effects within the biofilm and antibiofilm concentration was the same for each microorganism. Conclusion. The stabilized HOCl solution had dose-dependent favorable effects on fibroblast and keratinocyte migration compared to povidone iodine and media alone. These features lead to a stabilized HOCl solution as an ideal wound care agent.


Wound healing is a sequence of complex and well-orchestrated events. Although the precise mechanism of wound healing is not fully understood, 3 interrelated phases—inflammation, migration, and remodeling—require coordinated activity for successful wound healing, which is a progressive series of events facilitated by platelets, leukocytes, fibroblasts, and keratinocytes. Platelets facilitate homeostasis and the release of growth factors, then leukocytes participate in the inflammatory process. Fibroblasts and keratinocytes have a critical role in wound healing by enhancing reepithelization and the remodeling of the extracellular matrix (ECM).1-3

  Most chronic wounds are related to diabetes mellitus, venous stasis, peripheral vascular diseases, and pressure ulcerations. An open wound is a favorable niche for bacterial colonization and infection. Infection in chronic wounds starts with contamination, then colonization and critical colonization take place before an infection forms.

  Biofilm formation is now recognized as a serious problem in chronic wound infections.4 Biofilm is a complex structure of microorganisms that generate a protective shell, allowing bacteria to collect and proliferate.5 Most of the microorganisms that form biofilms can also be found growing in microbial infections. The same species of bacteria have significant differences in existence that range either free floating and living within the biofilm. The biofilm structure of microorganisms renders phagocytosis difficult,6 increases resistance to antibiotics,7 and adheres to unfavorable niches such as chronic wounds.8

  One of the remarkable features of the immune system against invading pathogens is its ability to generate an effective and rapid response by developing a group of highly reactive chemicals, such as reactive oxygen species (ROS). The mitochondrial membrane-bound enzyme nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) is a primary enzyme responsible for ROS production.9 During the activation of neutrophils, respiratory bursts generate hydrogen peroxide (H2O2) and the activated granule enzyme myeloperoxidase converts H2O2 to hypochlorous acid (HOCl) in the presence of Cl- and H+.10 Hypochlorous acid leads to cell death by the oxidation of sulfhydryl enzymes and amino acids, ring chlorination of amino acids, loss of intracellular contents, decreased uptake of nutrients, inhibition of protein synthesis, decreased oxygen uptake, oxidation of respiratory components, decreased adenosine triphosphate production, breaks in DNA, and depressed DNA synthesis.11-15 Hypochlorous acid is highly active against all bacterial, viral, and fungal human pathogens16 and a small amount of HOCl can kill spore-forming and non-spore bacteria in a short time period.17,18

  Since most of the etiologic factors in chronic wound infections are forming biofilm,19 and most of the topical antiseptics impair wound healing with their cytotoxic effect, therapeutic strategies against biofilm with high microbial eradication and good wound healing effects will decrease the morbidity and mortality rates of patients and reduce the economic burden. The aim of this study was to investigate the effect of stabilized HOCl solution on microbial and biofilm eradication, antimicrobial activity within biofilm against frequently isolated microorganisms, and migration rate of wounded fibroblasts and keratinocytes.

Materials and Methods

Reagents. Hypochlorous acid is generated from sodium hypochlorite and hydrogen peroxide reverse reaction. The concentration used in this study was 218 ppm, pH 7.1, ORP 871 MV and its stability was 24 months (NPS Biosidal, Istanbul, Turkey).

  Cell lines and microorganism strains. Skin fibroblast cell line (BJ ATCC CRL-2522, American Type Culture Collection, Manassas, VA) was grown in Eagle’s Minimum Essential Medium with 10% fetal bovine serum (Biological Industries, Kibbutz Beit-Haemek, Israel). Human skin keratinocyte cell line (CCD 1101 quarter, American Type Culture Collection, Manassas, VA) was grown in keratinocyte serum-free medium (Life Technologies, Carlsbad, CA). Slime producing Staphylococcus aureus (ATCC 35556) and Pseudomonas aeruginosa (ATCC 15692-PAO-1) were obtained from the Leibniz-Institut DSMZ GmbH (Braunschweig, Germany) and Candida albicans (ATCC 90028) from the American Type Culture Collection. Clinical isolates were obtained from the clinical microbiology laboratory of Adnan Menderes University Hospital Aydın, Turkey.

  Minimum bactericidal concentration and time kill assay. Inocula were prepared following the described guidelines of Clinical and Laboratory Standards Institute.20 The stabilized HOCl solution inactivated with organic materials and HOCl solution with serial dilutions of 1/2, 1/4, 1/8, 1/16, 1/32, and 1/64 (109, 55, 22.5, 11, 5.5, and 2.75 ppm, respectively) were prepared in sterile phosphate buffered saline (PBS) solution. Sterile PBS alone was used as a control. Hypochlorous acid dilutions and control were prepared in 10 ml tubes and inoculums were added with a final cell density of 105 cfu/ml and incubated at 37°C for 60 minutes for minimum bacterial concentration (MBC). A 10 µl sample was removed and plated on Mueller Hinton (MH) or Sabouraud dextrose agar (SDA) plates. After incubating for 24 hours at 37°C, the growths were observed. The concentration at which there was a complete absence of colony growth was determined to be the MBC.

  In time-kill (TK) studies, MBC concentrations of HOCl were inoculated with 105 cfu/ml of each organism and incubated for 0, 5, 10, 15, 20, 30, 60, and 90 minutes at 37°C. For each time point, 10 µl of inoculum was transferred to agar and incubated at 37°C for 24 hours. The time at which there was a complete absence of colony growth was determined to be the TK.

  To determine the accurate killing time of bacteria, green fluorescent protein (GFP)-transfected P. aeruginosa were exposed to 1/32 dilution (5.5 ppm) of HOCl and video recorded through fluorescence microscopy (Olympus, Tokyo, Japan).

  Antibiofilm and microbicidal effects of hypochlorous acid within biofilm. The ability of microorganisms to form biofilm on abiotic surfaces was quantified as described in Christensen et al.21 Briefly, microorganisms were grown overnight in Triptic soy broth (Sigma-Aldrich , St. Louis, MO) or Sabouraud dextrose broth (Sigma-Aldrich , St. Louis, MO) with 0.25% glucose at 37°C. The culture was diluted 1:40 in proper media, and 200 µL of this cell suspension was used to inoculate into wells of 2 groups of sterile 96-well polystyrene U-bottom microtiter plates. After 48 hours incubation at 37°C, wells were gently washed 3 times with 200 µL of sterile PBS and a 2-fold serially diluted HOCl and sterile PBS alone were added to each well and incubated for 24 hours at 37°C.

  One group of wells was used for biofilm eradication and the other for the microbicidal effect within the biofilm. After incubation, a biofilm-eradication group of wells was washed 3 times with PBS, dried in an inverted position and stained with 200 µL of 1% crystal violet for 15 minutes. Wells were rinsed and dried, and crystal violet was solubilized in ethanol-acetone (80:20, vol/vol). The optical density (OD) of well contents was determined at 595 nm using a microplate reader (Thermo Fisher Scientific, Milford, MA). A group of wells used to evaluate the bactericidal effect within the biofilm group was washed 3 times and each well was scraped and sonicated for 5 minutes in 100µl sterile PBS. Then, 10 µl of the contents of each well was plated on Mueller-Hinton or Sabouraud dextrose agar plates. Growth was observed after incubating for 24 hours at 37°C.

  Skin fibroblast and keratinocyte cell migration in a wound healing assay. Cells were cultured to confluence in the wells of 24-well plates (Corning Inc, Corning, NY). After 48 hours, a sterile 10 µl pipette tip was used to create a single wound across the diameter of each monolayer, and the medium was replaced with povidone iodine and HOCl solutions with serial dilutions of 1/2, 1/4, 1/8, 1/16, and 1/32 with PBS and PBS alone as a control, as previously described.22 The cells were then incubated at 37°C and 5% CO2. Images of each monolayer were captured at 0, 4, 8, and 24 hours.

  For determining the short time exposure effect of povidone iodine and HOCl, cells were treated with the serial dilutions of povidone iodine and HOCl solution for 10 minutes and rinsed with PBS. The cells were incubated in proper media at 37°C and 5% CO2 and images were captured at the time interval indicated above. Cell migration into the wound was calculated using the publicly available Image J software. Cell migration into each wound after 4, 8, and 24 hours was compared to the wounded monolayer at 0 hours.

Statistical Analysis
All experiments were repeated 3 times and each experimental and control condition assayed in triplicate. Analysis of variance (ANOVA) was used to compare the mean responses among experimental and control groups. A P value below 0.05 was considered statistically significant.


Minimal bactericidal concentration and time kill. Minimum bactericidal concentration of HOCl for all standard microorganisms was 1/64 dilution and for clinical isolates ranged from 1/32 to 1/64 dilutions (Table 1). All the microorganisms were killed within 0 minutes. The accurate killing time of HOCl on green fluorescent protein (GFP) expressing P. aeruginosa was 12 seconds (Figure 1).

  Antibiofilm and bactericidal effects of hypochlorous acid within biofilm. The treatment of microorganisms with stable HOCl solution decreased the amount of biofilm, and the amount of microorganisms within the biofilm with the dose-dependent manner depending on species.

  Although the effective concentration of the stable HOCl solution was varied between species, microbial killing rates within the biofilm was relevant to the biofilm impairment concentrations for each species. The effective dose of HOCl on biofilm impairment of S. aureus, P.aeruginosa, and C. albicans was 1/32, 1/16, and 1 dilution, respectively. The microbicidal effects within biofilm and antibiofilm concentration was the same for each of the microorganisms. These data showed HOCl has antibiofilm activity and actively penetrated through the biofilm and killed the microorganism within the biofilm (Figure 2).

  The effect of povidone iodine and stabilized hypochlorous acid solution on the skin fibroblast and human skin keratinocyte cell line migration in wound healing assay. Since antiseptic solutions have harmful effects on wound healing, the authors compared the effects of povidone iodine and stabilized HOCl on the injury-induced migratory response. Migration in wound healing assay with povidone iodine-treated skin fibroblast cells was disrupted and cells detached from the matrix in all concentrations and times. Contrastly, stabilized HOCl solution treatment migration was decreased in high concentrations (1/2 and 1/4 dilution), but increased in low concentrations when compared to the media control (Figures 3 and 4). In human skin keratinocyte cells, povidone iodine treatment decreased migration after 4 hours. Migration with a stabilized HOCl solution was the same when compared to the media control at 4 and 8 hours at all concentrations, but increased at 1/16 and 1/32 dilution at 24 hours (Figures 5 and 6). The 10-minute treatment results were the same as the long term treatment results (data not shown). These results suggest that a stabilized HOCl solution enhances wound healing in contrast to povidone iodine.


Chronic wounds increase morbidity and mortality of patients and cause a significant burden to health care systems. Most chronic lesions are related to diabetes mellitus, venous stasis, peripheral vascular disease, and pressure ulcerations. Two critical factors important in wound healing are infection and cellular interaction. Infection is a major problem in wound healing, and chronic wounds can become contaminated by surrounding skin, local environment, and endogenous sources. Theoretically, chronic wounds offer ideal conditions for biofilm production. Biofilm is a primary impediment to the healing of chronic wounds23 as it forms a physical barrier to bacteria from an external environment; provides a means for bacteria to communicate with each other, leading to an increase in virulence and antibiotic resistance; and provides an escape for bacteria from immune recognition.24 In the current study, the authors demonstrated stabilized HOCl solution had powerful (Table 1) and rapid (Figure 1) killing effects on common etiologic microorganisms and had antibiofilm and microbicidal effects within biofilm (Figure 2). Although it has been shown that many antiseptic solutions have microbicidal activities against various microorganisms, their activities varied between the type of microorganisms (eg, gram negative, gram positive, or yeasts).25-28 Previous studies have estimated that 106 neutrophils stimulated in vitro can produce 0.1µM HOCl and that this amount of HOCl can kill 1.5×107 E. coli in less than 5 minutes.17 Recently, Wang et al27 demonstrated that stabilized HOCl had antimicrobial activity against S. aureus, P.aeruginosa, and C. albicans at concentrations ranging from 0.1 to 2.8 µg/mL and its TK values for these organisms was less than 1 minute.28 These data correlated with the current study data but TK in this study was 0 minutes for all microorganisms.

 Many antiseptic agents have more potent antibiofilm effects than antibiotics.29-31 But the correlation between antibiofilm effect and microbicidal effect within biofilm has not been well described. In this study, the HOCl concentration for antibiofilm and microbicidal effects within biofilm was the same for each microorganism (Figure 2).

  Although the biofilm eradication concentrations varied for each microorganisms, this was not correlated with the amount of biofilm. Since organic materials inactivate the stabilized HOCl solution activity, the difference in biofilm eradication concentration may be due to the diversity of biofilm structures of microorganisms.

  Wound healing is a continuous sequence of 3 overlapping phases—inflammatory, proliferative, and maturation. At the inflammatory stage of injury, leukocytes have a critical role in the progress of the normal healing process.32,33 Granulation tissue formation in the wound initiates with the proliferative phase and consists of cellular elements such as fibroblasts, keratinocytes, and inflammatory cells. Fibroblasts,derived from local mesenchymal cells, are the primary synthetic cells in the repair process of most structural proteins used during tissue reconstruction.33 Although fibroblasts have a critical role in wound healing, its proliferation highly relates to keratinocyte proliferation and mediators secreted from keratinocytes and fibroblasts. Proinflammatory mediators, such as keratinocyte-derived IL-1 and inflammatory cell-derived IL-1, dominate keratinocyte-fibroblast interactions. Factors, such as keratinocyte growth factor, IL-6, endothelin-1 (ET-1), heparin-binding epidermal growth factor, and granulocte-monocyte colony stimulating factor, are upregulated in fibroblasts in response to IL-1. These factors stimulate keratinocyte proliferation and differentiation. Basement membrane constituents are also expressed by both keratinocytes and fibroblasts.34 The defects on this mechanism or the proliferation of these cells impairs healing and causes chronic wounds.

  Topical antiseptics in chronic wounds remain in widespread use today. These antiseptics are successful in microbial eradication, but at typical concentrations, they are cytotoxic and impair wound healing.25-27 To demonstrate the effect of a stabilized HOCl solution on wound healing, the authors compared the migration of a wounded monolayer with povidone iodine and media alone in a cell culture model. The povidone iodine treatment disrupted fibroblast migration and detached cells after 4 hours. Stabilized HOCl solution decreased fibroblast migration with high doses, but it increased with a low dose when compared to the media control (Figures 3 and 4). Stabilized HOCl solution-treated keratinocyte cells and migration increased after 8 hours of treatment with the dose-dependent manner compared to the media control. In contrast, povidone iodine decreased migration at all dilutions after 4 hours of treatment (Figures 5 and 6). Moreover, short term treatment had the same effects on fibroblasts and keratinocyte migration.

  Recent in vitro and clinical studies with super-oxidized solutions (SOS), supported these findings. In vitro studies with fibroblasts have shown that SOS is significantly less cytotoxic than hydrogen peroxide and does not induce genotoxicity or accelerated aging.35 In clinical studies with chronic diabetic foot ulcers, osteomyelitis, and pressure ulcer treatment, HOCl has been impeded by infectious complications without application of systematic antibiotic therapy and a shortened healing period without any local side effects such as allergy or dermal irritation.36,37


These findings support stabilized HOCl solution as an ideal wound care solution with a powerful and rapid killing effect on different types of microorganisms, antibiofilms, and microbicidal effect within the biofilm. Foremost, it has dose-dependent favorable effects on fibroblast and keratinocyte migration. These features lead to a stabilized HOCl solution as an ideal wound care agent. Randomized, prospective clinical trials are required to determine in vivo relevance of these findings.


The author would like to thank NPS Biosidal, Istanbul, Turkey, which provided the stabilized HOCl solution and keratinocyte cells for the purposes of this study.

Affiliations: Adnan Menderes University, School of Medicine, Department of Infectious Diseases and Clinical Microbiology, Aydin, Turkey; Adnan Menderes University, Adubiltem Research and Development Center, Aydin, Turkey; and Ataturk University, School of Medicine, Erzurum, Turkey

Serhan Sakarya, MD
Adnan Menderes University
Tıp Fakültesi Enfeksiyon Hastalıkları ve Kl. Mik A.D.
09100 Aydin, Turkey

Disclosure: The authors disclose no financial or other conflicts of interest.

OK Firefighters Create New, Fast Way to Disinfect Equipment

Developed by two Tulsa firefighters with items found in most stations, the spray system kills viruses, such as COVID-19, with hypochlorous acid, and it can be used to disinfect gear and apparatus. Apr 6th, 2020 (edited)

Oklahoma firefighters have created a fast-working way to disinfect equipment without damaging it, and the sprayer system comes as the department continues to combat the coronavirus.

Developed by two Tulsa firefighters, the system disinfects by spraying hypochlorous acid on the gear and apparatus, killing viruses in 60 seconds without needing to be wiped off, KOTV-TV reports. Currently, firefighters use a bleach product to disinfect equipment, which can be a time-consuming process.

“Our own employees figured out a way to make this mobile and efficient and quick,” Andy Little, a Tulsa Fire Department spokesman, told KOTV.

One of the biggest benefits of the system is that it can be used on practically every bit of equipment used by firefighters, including patient blood pressure cuffs and the inside of ambulances and other vehicles. The system also can be put together out of items found at most fire stations.

“As of now, we’ve treated the dispatch center, and we’ve treated numerous police cars, because it’s an issue. They’re picking up numerous people and there’s no way to know if those people are exposed or not” Little told KOTV.

Eventually, all of the stations will have the new disinfection system, and firefighters would use it following every medical call. And with every U.S. community caught in the coronavirus pandemic, the department is sharing the system’s plans with their fellow firefighters. 


Look inside Scottish club Hamilton’s new coronavirus ‘disinfectant tunnel’ that sprays players with fine mist of acid

HAMILTON ACADEMICAL have shown off their new ‘disinfectant tunnel’ in a bid to get Scottish football back safely from the coronavirus shutdown., May 28th 2020

The Premiership side showcased the system to the nation earlier today during ITV’s Good Morning Britain show.

 Hamilton's new chamber was showcased on Good Morning Britain
Hamilton’s new chamber was showcased on Good Morning Britain
 Players will be sprayed with a mist to kill off any germs
Players will be sprayed with a mist to kill off any germs

Accies players will undergo a temperature check before moving on to the next line of security.

Brian Rice and his squad will then enter the decontamination chamber on their way out to the pitch and will be sprayed with a fine mist of acid.

The idea behind it is to give players and staff some more reassurance amid the Covid-19 crisis with any germs on individuals hair, clothes, skin etc all banished.

The chamber inflates in just ONE minute and it can be packed into a small case for easy transportation.

John McMenemy of Core Physio said: “I want to point out that this is a barrage of processes.

“It doesn’t take the place of mindful hand washing or distancing. It is an addition.”

 The chamber inflates in just one minute and is easily transported
The chamber inflates in just one minute and is easily transported

He added: “The hard thing for us was how do we take this in a scalable and affordable way that would suit and keep the function and science behind it.

“It inflates in one minute and packs away in a small case that can be transported easy enough.”

Scottish football remains at a standstill due to the cornavirus pandemic.

But clubs will hope this measure will speed up a return to football at the top level.

Celtic were last week declared Premiership winners after the SPFL brought an end to the league campaign.

New Sanitizing Technology Makes Quick Work of COVID-19 (edited)

Sanitation is an essential component of cruise ship operation, and in recent months it has become an even more critical component. Global port authorities around the world are carefully screening for COVID-19 coronavirus along with other illnesses such as the common flu, all of which could lead to delays or denial of permission for ships to enter ports. 

This new health challenge calls for new sanitation solutions. [Cruise] ships usually use heavy-duty chemical disinfectants, but there is a better and safer way. Electrolyzed water – also known as hypochlorous acid (HOCl) – is a highly effective and intrinsically safe sanitizing agent, and it can be generated in unlimited quantities. 

The single most important feature of hypochlorous acid is that it is unusually efficient in eliminating viruses. “One of the big reasons why people are switching over is efficacy. Working with Cruise Lines, we did research at a FDA-approved lab proving that electrolytically generated hypochlorous acid can kill norovirus in less than one minute at 50 ppm. Given that norovirus is listed by the CDC as one of the top five foodborne pathogens, this has huge implications not just for general sanitation but also for food sanitation and food contact surface sanitation,” says Dr. Scott Hartnett, chief medical officer at one HOCl supplying company. 

National and international reference laboratories have proven that HOCl works very well against viruses, including norovirus and human coronaviruses. One study is of particular interest: in 2016, researchers at the University of Washington School of Public Health found that HOCl was more than 99.999 percent effective in eliminating coronavirus OC43, which is similar to COVID-19.

A proven solution for cruise ships

HOCl technology is already in use aboard ships in Cruise Lines fleet. “We use a hypochlorous acid system on board because of its proven effectiveness in killing bacteria, fungi and viruses,” says Robert Wilkinson, Senior Director of Environmental Health and Occupational Safety for Norwegian Cruise Line Holdings. “It reduces our dependence on the usual harsh chemicals and provides and additional layer of safety for our crewmembers and guests. Our shipboard teams truly appreciate the deployment of this new technology.” 

Wilkinson notes that HOCl is the rare single product that can be used to disinfect every compartment onboard, from galleys and dining areas to cabins. HOCl is FDA-cleared for washing fish and seafood, fruits and vegetables and sanitation of food prep surfaces without rinsing – making it a perfect choice for the galley. It is also listed by the USDA as an authorized material for use in organic food production. 

For large-scale disinfection, HOCl can be dispensed using a fogger without any chemical-related PPE for workers. HOCl is intrinsically safe, as it is non-irritant and the human body produces the same molecule for self-defense. In fact, it is so safe to inhale that it is being evaluated as a treatment for throat and lung infections. By contrast, the preparatory steps required for other fogging agents of similar power – products based on peracetic acid, ozone, chlorine dioxide or peroxides – require considerable time and expense. 

In hotel areas of the ship, HOCl has an extra edge over bleach and peroxide-based chemicals because it will not cause discoloration of most carpets, furniture and textiles. This is a critical economic and operational consideration when disinfecting hundreds of cabins. 

Unlimited quantities

With modern technology, HOCl can be generated in unlimited quantities using only electricity, table salt and water.  With unlimited on-board HOCl generation, there is no need to resupply the ship with toxic cleaning products. This reduces the ship’s supply chain costs and the need to carry toxic chemicals on board and is an effective and practical solution to a mission-critical challenge. 

With better efficacy and safety, unlimited capacity and ship-wide usability, hypochlorous acid is a superior solution for disinfection.

Detection of Severe Acute Respiratory Syndrome Coronavirus 2 RNA on Surfaces in Quarantine Rooms

Volume 26, Number 9—September 2020

Centers for Disease Control and Prevention, U.S. Department of Health & Human Services

Fa-Chun Jiang1, Xiao-Lin Jiang1, Zhao-Guo Wang, Zhao-Hai Meng, Shou-Feng Shao, Benjamin D. Anderson, and Mai-Juan Ma  Author affiliations: Qingdao Municipal Center for Disease Control and Prevention, Qingdao, China (F.-C. Jiang, Z.-G. Wang, Z.-H. Meng, S.-F. Shao); Shandong Provincial Center for Disease Control and Prevention, Jinan, China (X.-L. Jiang); Global Health Research Center, Duke Kunshan University, Kunshan, China (B.D. Anderson); State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China (M.-J. Ma)


We investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination in 2 rooms of a quarantine hotel after 2 presymptomatic persons who stayed there were laboratory-confirmed as having coronavirus disease. We detected SARS-CoV-2 RNA on 8 (36%) of 22 surfaces, as well as on the pillow cover, sheet, and duvet cover.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread globally and. as of May 2, 2020, had caused >3 million confirmed coronavirus disease cases (1). Although SARS-CoV-2 transmission through respiratory droplets and direct contact is clear, the potential for transmission through contact with surfaces or objects contaminated with SARS-CoV-2 is poorly understood (2). The virus can be detected on various surfaces in the contaminated environment from symptomatic and paucisymptomatic patients (3,4). Moreover, we recently reported detection of SARS-CoV-2 RNA on environmental surfaces of a symptomatic patient’s household (5). Because SARS-CoV-2 remains viable and infectious from hours to days on surfaces (6,7), contact with a contaminated surface potentially could be a medium for virus transmission. In addition, high viral load in throat swab specimens at symptom onset (8,9) and peak infectiousness at 0–2 days for presymptomatic patients (8) suggest that presymptomatic patients may easily contaminate the environment. However, data are limited on environmental contamination of SARS-CoV-2 by patients who may be presymptomatic. Therefore, to test this hypothesis, we examined the presence of SARS-CoV-2 RNA in collected environmental surface swab specimens from 2 rooms of a centralized quarantine hotel where 2 presymptomatic patients had stayed.

The Study

Two Chinese students studying overseas returned to China on March 19 (patient A) and March 20 (patient B), 2020 (Table 1). On the day of their arrival in China, neither had fever or clinical symptoms, and they were transferred to a hotel for a 14-day quarantine. They had normal body temperatures (patient A, 36.3°C; patient B, 36.5°C) and no symptoms when they checked into the hotel. During the quarantine period, local medical staff were to monitor their body temperature and symptoms each morning and afternoon. On the morning of the second day of quarantine, they had no fever (patient A, 36.2°C for patient A; patient B, 36.7°C) or symptoms. At the same time their temperatures were taken, throat swab samples were collected; both tested positive for SARS-CoV-2 RNA by real-time reverse transcription PCR (rRT-PCR). The students were transferred to a local hospital for treatment. At admission, they remained presymptomatic, but nasopharyngeal swab, sputum, and fecal samples were positive for SARS-CoV-2 RNA with high viral loads (Table 1). In patient A, fever (37.5°C) and cough developed on day 2 of hospitalization, but his chest computed tomography images showed no significant abnormality during hospitalization. In patient B, fever (37.9°C) and cough developed on day 6 of hospitalization, and her computed tomography images showed ground-glass opacities.

Approximately 3 hours after the 2 patients were identified as positive for SARS-CoV-2 RNA, we sampled the environmental surfaces of the 2 rooms in the centralized quarantine hotel in which they had stayed. Because of the SARS-CoV-2 outbreak in China, the hotel had been closed during January 24–March 18, 2020. Therefore, only these 2 persons had stayed in the rooms. We used a sterile polyester-tipped applicator, premoistened in viral transport medium, to sample the surfaces of the door handle, light switch, faucet handle, thermometer, television remote, pillow cover, duvet cover, sheet, towel, bathroom door handle, and toilet seat and flushing button. We also collected control swab samples from 1 unoccupied room. We collected each sample by swabbing each individual surface. We tested the samples with an rRT-PCR test kit (DAAN GENE Ltd, targeting the open reading frame 1ab (ORF1ab) and N genes of SARS-CoV-2. We interpreted cycle threshold (Ct) <40 as positive for SARS-CoV-2 RNA and Ct >40 as negative.

We collected a total of 22 samples from the 2 rooms of the quarantine hotel (Table 2). Eight (36%) samples were positive for SARS-CoV-2 RNA. Ct values ranged from 28.75 to 37.59 (median 35.64). Six (55%) of 11 samples collected from the room of patient A were positive for SARS-CoV-2 RNA. Surface samples collected from the sheet, duvet cover, pillow cover, and towel tested positive for SARS-CoV-2 RNA, and surface samples collected from the pillow cover and sheet had a high viral load; Ct for ORF1ab gene from the pillow cover was 28.97 and from the sheet, 30.58. Moreover, the Ct values of these 2 samples correlated with those of patient A’s nasopharyngeal (24.73) and fecal (33.12) swab samples at hospital admission. One surface sample from the faucet in patient B’s room was positive for SARS-CoV-2 RNA; the Ct was 28.75 for the ORF1ab gene. Again, we detected SARS-CoV-2 RNA from the surface samples of the pillow cover; Ct was 34.57. All control swab samples were negative for SARS-CoV-2 RNA.


Our study demonstrates extensive environmental contamination of SARS-CoV-2 RNA in a relatively short time (<24 hours) in occupied rooms of 2 persons who were presymptomatic. We also detected SARS-CoV-2 RNA in the surface swab samples of the pillow cover, duvet cover, and sheet.

Evidence for SARS-CoV-2 transmission by indirect contact was identified in a cluster of infections at a shopping mall in China (10). However, no clear evidence of infection caused by contact with the contaminated environment was found. SARS-CoV-2 RNA has been detected on environmental surfaces in isolation rooms where the symptomatic or paucisymptomatic patients stayed for several days (35). In our study, we demonstrate high viral load shedding in presymptomatic patients, which is consistent with previous studies (8,9), providing further evidence for the presymptomatic transmission of the virus (5,1115). In addition, presymptomatic patients with high viral load shedding can easily contaminate the environment in a short period.

Our results also indicate a higher viral load detected after prolonged contact with sheets and pillow covers than with intermittent contact with the door handle and light switch. The detection of SARS-CoV-2 RNA in the surface samples of the sheet, duvet cover, and pillow cover highlights the importance of proper handling procedures when changing or laundering used linens of SARS-CoV-2 patients. Thus, to minimize the possibility of dispersing virus through the air, we recommend that used linens not be shaken upon removal and that laundered items be thoroughly cleaned and dried to prevent additional spread.

The absence of viral isolation in our investigation was an obstacle to demonstrating the infectivity of the virus, but SARS-CoV-2 has been reported to remain viable on surfaces of plastic and stainless steel for up to 4–7 days (6,7) and 1 day for treated cloth (7). In summary, our study demonstrates that presymptomatic patients have high viral load shedding and can easily contaminate environments. Our data also reaffirm the potential role of surface contamination in the transmission of SARS-CoV-2 and the importance of strict surface hygiene practices, including regarding linens of SARS-CoV-2 patients.

Dr. Jiang is an epidemiologist in Qingdao Center for Disease Control and Prevention, Qingdao, Shandong Province, China. His primary research interests included infectious disease control and prevention and emerging infectious diseases.


This work was supported by the National Major Project for Control and Prevention of Infectious Disease of China (2017ZX10303401-006), the National Natural Science Foundation of China (81773494 and 81621005), and the Special National Project on investigation of basic resources of China (2019FY101502).


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Suggested citation for this article: Jiang FC, Jiang XL, Wang ZG, Meng ZH, Shao SF, Anderson BD, et al. Detection of severe acute respiratory syndrome coronavirus 2 RNA on surfaces in quarantine rooms. Emerg Infect Dis. 2020 Sep [date cited].

DOI: 10.3201/eid2609.201435

Original Publication Date: May 18, 2020