The Centre on Monday told the Supreme Court that it has nowhere issued any guidelines for using and installing disinfection tunnels, involving spraying or fumigation of chemical on people in the workplace and public places.
Spraying disinfectants, even outdoors, can be harmful to human health, it added.
In an affidavit, the Ministry of Health and Family Welfare said on June 9, an expert committee meeting under the chairmanship of Directorate General of Health Services, was held to review the use of disinfectant tunnels, use of various chemicals, spraying and its efficacy.
"It was reiterated that spraying of the individuals with the disinfectants, such as tunnels, cabinets and chambers etc is not recommended as it would not diminish the infected person's ability to spread the coronavirus through droplets or contacts," it said.
It is also not recommended in healthcare and non-healthcare settings.
"If disinfectant was to be applied in indoor spaces, this should be done with a cloth or wipe that has been soaked in disinfectant," it said.
The Union government said spraying and fumigation of outdoor spaces such as streets and marketplaces is also not recommended to kill Covid-19 virus or other pathogens because disinfectant is inactivated by dirt and debris.
The response was filed in a PIL filed by Gursimran Singh Narula, a final law year student, who sought a direction for banning sanitisation tunnels.