During the Covid-19 pandemic, sanitiser spray machines, also known as nano mist sanitiser guns are now permanent fixtures in shops, cars, and many homes, ostensibly to sanitise items and keep the virus at bay.
Online shopping malls are promoting them, with prices ranging from RM20 to as high as RM150, with one seller moving over 10,000 units a month on one platform.
With a pull of a trigger, the battery-powered machine produces a “nano” mist from a bottle containing a mix of bleach and water besides other chemical concoctions, touted to kill germs and viruses. Some also claim to come with germ-busting UV lights, creating a blue glow when triggered.
Bottles of chlorine dioxide tablets are supplied to be mixed with water in the bottle attachment, while some products push different germ-killing formulations such as hypochlorous acid and more.
But the question remains, is it safe to be used on people?
Researchers said it is not. Such devices can be sprayed on objects and surfaces but should never be sprayed on people, let alone inhaled.
However, unscrupulous traders online are touting it to be a great sanitiser to be used on the hands and other parts of the body. These advertisements also claim they are “FDA and KKM approved”.
Even more troubling, checks at a mall here showed dine-in outlets spraying patrons with the vapour – essentially bleach mixed with water – from such “guns”.
Universiti Sains Malaysia’s (USM) Amirah Mohd Gazzali said bleach mixes, such as chlorine dioxide like the ones being sold online, are not good for the skin, as they could cause serious health problems, including tissue and blood cell damage.
If inhaled, she said it may cause lung oedema in serious cases while lesser symptoms include coughing and sore throat. Blurry vision and watery eyes are also some of the side effects.
“These symptoms may begin to show after some time, and not immediately, and could remain for a certain time,” the lecturer at USM’s pharmaceutical sciences school said.
Amirah said chlorine dioxide mixes may explode if stored in hot places and produce irritating chlorine odour if stored under light. Light causes decomposition of such mixes, she said.
She said that those using such sprays indoors or in confined spaces also run the risk of causing an explosion if there is just 10% of chlorine dioxide in the air.
According to Amirah, bleach mixes are typically used to clean electronic circuit boards, as well as for use in textile bleaching, candle making, and producing paper.
“Chlorine dioxide gas can also be used to sterilise medical and lab equipment, including treating sewage water.
“It is a strong oxidising agent, which can kill all microorganisms, including viruses, effectively,” she said.
Amirah added that the mist which the gun creates is so small that it is easily absorbed through the skin and may even pass through the throat unnoticed.
“Nano-type sprays or foggers should only be used by professionals, and in almost all cases, should be used on materials or surfaces, never on humans,” the expert in drug delivery and formulation said.
In the context of killing the virus that causes Covid-19, USM’s Kumitaa Theva Das said that in the earlier days of the virus, sanitation tunnels spraying similar chemicals were proven ineffective to be used on people.
The virologist said the best way was to spray disinfectants on tables and other high-contact areas such as door handles and to wipe them with a clean cloth.
Kumitaa also dismissed a suggestion that such gun sanitisers could spread Covid-19, as warned by Thai authorities recently.
Recently, the Thai Food and Drug Administration issued a warning against the use of alcohol spray guns, saying it may spread viruses widely and also carry the risk of skin cancer due to the UV lights.