Two children being sprayed with disinfectant at the airport before being sent to a quarantine centre. 
Pic by Pradeep Dilrukshana

Security personnel and health workers disinfecting public places has become a common sight, widely captured by the media. Furthermore, decontamination chambers are being installed at workplaces for staff to disinfect themselves before entering. Returnees from foreign countries and those leaving quarantine centres too are being sprayed with disinfectants. But medical professionals have warned against these methods, especially as they pose serious individual health risks and could undermine the overall fight against COVID-19.

WHO warning

The World Health Organisation (WHO) strongly advises that the spraying disinfectants on individuals or groups is not recommended under any circumstances. Spraying an individual or group with chemical disinfectants or detergents is physically and psychologically harmful and does not limit the spread of COVID-19. Even if a person is infected with COVID-19, spraying the external parts of the body does not kill the virus inside the body and may worsen the person’s clinical condition. In particular, spraying of chlorine on persons could lead to irritation of the eyes and skin, bronchospasm due to inhalation, and potentially gastrointestinal effects like nausea and vomiting.  

"Decontamination chambers and widespread spraying could also give a false sense of security, and the public may pay less attention to hand hygiene, social distancing"

Multiple health risks

The Sri Lanka College of Microbiologists (SLCM) citing the US Food and Drug Administration (FDA) said in a press release that for ozone to be effective in destroying harmful bacteria it must be present in concentrations above levels considered safe for humans. It added inhaled ozone gas could damage the lungs, worsen chronic respiratory diseases like asthma, and compromise the ability of the body to fight respiratory infections. Excessive exposure to Ultra Violet (UV)light could risk eye injury, skin burns or even increase the risk of skin cancer. To date, the FDA has not authorised any products using ozone gas or UV light even to clean, disinfect or sanitize inanimate objects.   
The SLCM noted disinfectants should be used only on surfaces that are highly or frequently touched by the public like hand railings, door knobs, poles on transit vehicles, elevator buttons, park and street benches and so on. The virus can survive for hours or days on these contaminated surfaces. But spraying large quantities of disinfectants on the environment could result in pollution, wastage of chemicals and harmful effects on animals and fish. 
Further, the impact of these disinfectants on outdoor surfaces have not yet been evaluated since disinfectants could disintegrate or degrade with exposure to environmental conditions like sunlight.   
Decontamination chambers and widespread spraying could also give a false sense of security, and the public may pay less attention to hand hygiene, social distancing and cough etiquette and respiratory hygiene, which are paramount in fighting COVID-19.

Like chemical weapons 

Dr. Mahen Kothalawala, Consultant Clinical Microbiologist at the Kandy Teaching Hospital, said there were three types of chemicals including sodium/calcium hypochlorite, more than 60% alcohol and ozonide. “These are disinfectants and they are being used on inanimate objects. If you want to apply something on an animate object, it should be an antiseptic. There itself we have gotten it wrong. Using hypochlorite is like using a chemical weapon, because it could accumulate in your body.

You could get chemical pneumonitis, allergies and other health issues. People will be at risk of getting dermatitis and alcoholic inflammation. There is also a risk of these chambers catching fire due to alcohol content. It is also important to note that the ethanol used in these chambers have been adulterated with various additives. For example, they add castor oil to give a strong smell. Even ozone at a certain level is harmful to humans,” he said.  

Further explaining the six components in the chain of infections, Dr. Kothalawala said to stop COVID-19, this chain had to be broken. “But disinfectants don’t contribute to breaking this chain. The virus would spread through contact or droplets, and disinfectants do not affect the mode of transmission. Once a person steps out of a decontamination chamber, they are again vulnerable to the disease.”  

When asked about spraying individuals with disinfectants at quarantine centres and public places, Dr. Kothalawala said this may be done to curb the spreading of the virus. “At this point we have to stop community spread. So far it hasn’t reached hospitals. Therefore, to stop community spread you need to maintain physical distancing, use hand sanitizers and alcohol rubs to clean door knobs and frequently touched surfaces, stay indoors and so on. Spraying disinfectants will have a placebo effect, but not the desired effect,” he said.   

Sri Lanka army troops in Mullaitivu disinfecting public places. Pic - Sri Lanka Army