LETTERS: A recent issue raised by the Consumers Association of Penang involved the safety of sanitising liquids, especially the use of sanitising tools such as rechargeable sprays or guns that generate mist.
By now, consumers should be aware of the choice of disinfectants that are safe to use. It is important to remind the public that alcohols (60 to 80 per cent of ethanol and isopropanol) are safe and efficacious disinfectants recommended by the World Health Organisation to be used on humans.
Non-alcohol disinfectants such as benzalkonium chloride and sodium hypochlorite (bleaching agent) are used for surface disinfection.
The safety of such disinfectants to be used for food and related packaging has not been established but these are known to cause irritation and not safe for human consumption.
WHO has stated that there is no evidence to show that people can catch Covid-19 from food, including fruits and vegetables.
If you are doubtful of the disinfectant provided, especially at the supermarkets or restaurants, bring your own sanitisers that are compatible with your skin.
You can visit the official website of the National Pharmaceutical Regulatory Agency of the Health Healthy, and search under the cosmetic product category for the notification on disinfectants (https://www.npra.gov.my/index.php/en/consumers/information/products-sear...).
Instead of getting from an unknown source or seller, it is best to consult your community pharmacist.
While we hope the mist generated kills the viruses around us and the surroundings, most of the mist may have disappeared, especially in a vast space or well-ventilated environment.
The question remains whether the mist generated by the sanitising gun is effective to kill the viruses. The way this gun works is similar to the disinfecting tunnels, which were popularly used for sanitising humans in the early pandemic stage.
However, WHO has discouraged the use of such tunnels for humans because the risk outweighs the benefit. The risk refers to the exposure of the human body to the disinfectant, including skin exposure, inhalation and eye contact.
These organs are known to be sensitive and easily irritated by exposure to an inappropriate or long exposure to disinfectants. It is recommended to use the sanitising gun or fogging machine for surface disinfectant only.
Be careful of the choice and compatility of the disinfectants used. Alcohols are inflammable and should not be used with sanitising guns. Burning incidents due to the use and charging of guns have been reported elsewhere.
On another note, contact time is crucial for disinfectants to work effectively. Hold the gun to face the disinfection site for a sufficient time — usually 30 seconds are needed.
It is also recommended to wet the surface with the mist for proper contact because most of the mist may have contacted the air before disappearing.
We have to remember that vaccine is not a magic bullet. Basic hygiene practices are still pivotal to curb the spread of infection. Therefore, we must learn to recognise, choose and handle disinfectants properly.
Dr Goh Choon Fu
Senior lecturer and leading researcher, Skin Research Group, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang
The views expressed in this article are the author's own and do not necessarily reflect those of the New Straits Times