There are currently no sanitisers which have been specified as safe for use in fogging solutions in coronavirus disinfection tunnels deployed around South Africa.
This is according the Council of Scientific and Industrial Research (CSIR), which spoke to MyBroadband following comments by the Health Minister’s COVID-19 advisory committee which recommended these tunnels not be permitted as a measure to curb the spread of COVID-19.
Head of the committee Professor Salim Abdool Karim said the spraying of humans with chemicals in fumigation tunnels is potentially dangerous as it can damage the eyes, cause skin rashes, and affect breathing.
The professor said there was little or no evidence for the safety of the chemicals that are used and the side-effects remain largely unknown.
In addition, he said the tunnels do not offer any benefit in curbing the spread of the virus, as it is primarily transmitted through contact with the mouth, nose, and eyes.
The tunnels are therefore not deemed to be safe or effective for COVID-19 disinfection.
There are a number of sanitising agents known to be employed in these tunnels or booths used around the world.
The primary issue is that while certain chemicals have been found to be safe for human consumption and use on hands, none have undergone the necessary standards testing to be approved for spraying on humans in particular.
Solutions used in these tunnels often contain sodium sulphate, sodium hypochlorite, or benzalkonium chloride.
Potentially toxic and harmful chemicals
Senior researcher at the Council for Scientific and Industrial Research (CSIR) Peta de Jager told MyBroadband it is correct to question safety claims made by manufacturers.
“There have been very nasty consequences when people have been disinfected using chlorine in an Ebola outbreak in West Africa,” De Jager stated.
She said according to the WHO’s interim guidance on cleaning and disinfection of environmental surfaces in the context of COVID-19, there is currently no accommodation for fogging tunnels.
She directed MyBroadband to a useful list of disinfectants for use against the COVID-19 coronavirus published by the US Environmental Protection Agency (EPA).
“Sodium sulphate and benzalkonium chloride do not appear on this list, so don’t seem to be sanitising agents,” De Jager stated.
“Sodium hypochlorite will be effective against coronavirus, but it is very unsuitable for fogging applications because if it inhaled or ingested it is extremely toxic and harmful, with powerful oxidising properties,” De Jager warned.
De Jager said it was important to assess whether the sanitisers used were approved for the application at hand – in this case – for spraying over persons who are wearing no additional protective equipment.
“Disinfection techniques and substances are well-researched using many methods and against many pathogens, including human coronavirus. No silver bullet (i.e both safe and effective) suitable for fogging people has yet been found,” De Jager said.
“In this case, the relevant concern is for the safety and efficacy of potentially toxic, corrosive, or otherwise harmful substances when applied in an aerosolised format (fogging) to a population with variable tolerance to these substances which could include asthmatics, persons with allergies, children and so on,” De Jager said.
She added the indiscriminate use and disposal of substances could pollute the environment and leave harmful residues.
“The international scientific community are on high alert and willing to review and test promising techniques or technologies in the effort to find the most effective approaches to addressing COVID-19. When we find better information, the guidance will be sure to be updated.”
MyBroadband also contacted the South African Bureau of Standards (SABS), which confirmed there was no standard specified for a substance which is both safe and effective against COVID-19 in a fogging tunnel or booth.
Anti Vi responds
One of the tunnels which MyBroadband had previously reported on – the Anti Vi – was rolled out at a Spar in Nelspruit earlier this year.
Responding to Professor Karim’s comments, Anti Vi refuted the implication that agents used in all the coronavirus disinfection tunnels were harmful to humans.
“While we applaud Professor Karim for the work he has done thus far in the fight against the virus, we could not help but feel that he had painted everyone in our line of business with the proverbial same brush,” the company said
“Dr Karim’s opinion appears to be largely based on the fact that the chlorine and other chemicals convert to hydrochloric acid (HCL), which could damage the eyes, skin and respiratory system which could then increase the risk of SARS-COV2 infection,” Anti Vi Stated.
The company said it had conducted its own thorough research to get an appropriate and safe disinfectant, endorsed, and approved by recognised quality control bodies.
“Although other disinfectants were also recommended as safe for use and with SABS certification, we have recalled all such disinfectant that has left our factory and replaced it with Viral Shield.”
“The product is not alcohol-based and contains no chemicals which are harmful to human users such as chlorine,” the company noted.
Anti Vi listed a number of applications for which the active ingredient in Viral Shield – Ionic Cupric Copper – is supposedly used, including:
- As a micronutrient in fertiliser due to being bio-degradable.
- As a nasal spray and open diabetic wounds disinfectant in Malaysia.
- To clean drinking water in pipes in Canada (NSF-ANSI 60 accredited).
Viral Shield is being sold in South Africa as a hand sanitiser and used in humidifying machines. The company is also selling its own tunnel solution.
Safety and effectiveness
Multiple studies have shown that copper has antimicrobial properties which could potentially be used to kill the COVID-19 coronavirus.
The Ionic Cupric Copper (INC) used in Viral Shield has been tested by Dr Wang Sheng of the Beijing University of Technology.
Sheng’s experiment found that it showed a long-lasting anti-viral activity against the COVID-19 coronavirus.
“Killing activity of INC is mediated via a way of contact killing, suggesting that INC can kill virus anytime a virus is in contact with INC – so, in theory, its virus killing can last for longer than 24 hours,” Sheng stated.
Among the documents furnished as proof of Viral Shield’s safety, Anti Vi provided a Material Safety Data Sheet (MSDS) which states that no harmful effects are expected should the substance come into contact with eyes or skin, granted it is used in “normal industrial use at room temperature”.
The sheet further indicated no harm was expected as a result of inhalation or ingestion, either, while there are no known symptoms or signs of exposure to the chemical.
However, the document does recommend the use of chemical goggles and a face shield as a precaution when splashing of the material may occur.
No substance with copper is currently listed on the EPA’s list of disinfectants for COVID-19.
Anti Vi told MyBroadband it has temporarily suspended use of its systems until further clarity is provided around the safety of Viral Shield as a fogging disinfectant in particular.
Below are several examples of COVID-19 disinfection tunnels being used in South Africa.