Even without scientific proof of their effectiveness in combating the novel coronavirus, disinfection structures (chambers, booths, or tunnels) continue to proliferate across the country and, in some cases, are even required by city governments in high-traffic areas such as shopping malls, commercial buildings, and bus terminals. “Anvisa itself acknowledges that these structures are not effective for inactivating the virus. Worse than that, some sprayed products can be harmful to health,” explains Paulo Engler, executive director of the Brazilian Association of the Household and Institutional Cleaning and Sanitizing Products Industry (Abipla).
Abipla has been analyzing these structures since they first appeared in Brazil. In April, for example, it issued a joint statement with the Federal Council of Chemistry (CFQ/CRQ) questioning the effectiveness of this equipment. ANVISA's response came in May through Technical Note 38/2020, in which the health agency states that the equipment is not recommended by any of the world's major health regulatory agencies. “No recommendations were found from bodies such as the World Health Organization (OMS), the US Food and Drug Administration (FDA), or the US Centers for Disease Control and Prevention (CDC) regarding the disinfection of people in the fight against Covid-19 through tunnels or chambers. Likewise, there is no recommendation from the European Chemicals Agency (ECHA) to that effect,” the text states.
Even with ANVISA's warning, many public places have been receiving the equipment and, in some cases, making it mandatory under local legislation. “We have sent official letters to various municipalities that started using such tunnels and booths, but most have ignored our recommendations and ANVISA's Technical Note. The City Council of São Paulo, for example, has already issued a legality opinion on Bill 365/20, which authorizes the use of this equipment, even making its installation part of the legal requirements to obtain an operating license,” states Engler.
Why doesn't it work?
Even though the products used in these structures are approved by Anvisa, the exposure time – generally 20 to 30 seconds – does not allow the disinfectant to complete the disinfection process, as some require up to 10 minutes of direct contact with the surface to be effective. “An additional problem is that the use of these structures may give people a false sense of security and, consequently, lead to the relaxation of social distancing practices, frequent hand washing with soap and water, surface disinfection, and other prevention measures,” states the Anvisa Technical Note.
Furthermore, sanitizing products have been approved exclusively for surface cleaning. Therefore, some of them can cause allergic reactions and even reduce the human skin's natural ability to fight harmful microorganisms if they come into direct contact with hands and mucous membranes. “Sodium hypochlorite, for example, is a corrosive product. It can cause skin and eye injuries, as well as respiratory problems. Other products that have been used, quaternary ammonium compounds, although not corrosive, can cause allergic reactions. As we have warned since the emergence of these structures, sanitizing products approved by Anvisa are totally safe as long as they are used correctly—that is, they must be applied to fixed, inanimate surfaces such as countertops, floors, walls, and objects, but never directly on humans,” says Engler.
source:
CIPA
