CORONAVIRUS | The Health Ministry has reiterated its recommendation against using "disinfection tunnels" as they have not been proven to be effective against Covid-19.

Also known as disinfection chambers, boxes or booths; such devices spray disinfectants on users as an apparent deterrent against the virus.

In his media briefing this evening, Health director-general Dr Noor Hisham Abdullah cautioned against using them and noted some possible harmful effects.

“There is no clinical evidence to suggest that it is actually beneficial or (can) even protect the person. We are worried that using this tunnel is not going to disinfect a person because the virus is in the body, not on the surface.

“We are worried about the chemical used to spray a person... it might cause irritation to the skin and eyes (and) it may also trigger an asthmatic attack,” he said, repeating his warning issued in an April 15 press conference.

“We do not encourage the usage of the tunnel,” he stressed.

Earlier today, the ministry issued similar advice on its official Facebook page, adding that resources were better invested in providing more hand washing facilities or hand sanitisers.

The World Health Organization (WHO) also does not recommend using disinfection tunnels “under any circumstances”.

“This practice could be physically and psychologically harmful and would not reduce an infected person’s ability to spread the virus through droplets or contact.

“Even if someone who is infected with Covid-19 goes through a disinfection tunnel or chamber, as soon as they start speaking, coughing or sneezing they can still spread the virus,” the global health authority said in a question and answer article.

The Health Ministry' Health Technology Assessment Section had carried out its own review of the available evidence up to April 27, and published its findings on May 19.

The review studied various disinfection tunnel designs offered in Malaysia and abroad, and said its efficacy is "uncertain" and it may cause harm to users.

It also said the contact time of 20 to 30 seconds with the disinfectant chemicals will be insufficient to inactivate the coronavirus.

"Hence, the use of disinfection box/ chamber/ tunnel/ booth/ partition/ gate in reducing Covid-19 transmission may not be recommended given the lack of scientific evidence and unclear risk-benefit profile," the document read.

For the record, most disinfectants recommended by the US Environmental Protection Agency for use against Covid-19 are only intended for use on hard, non-porous surfaces, which must remain in contact with the disinfectant for several minutes.

Most health authorities including the Health Ministry and the WHO recommend handwashing with soap and water instead, while hand sanitisers containing at least 60 percent alcohol may be used if soap and water is not available.