None of this is necessary for non-healthcare workers, since the virus will die off on a fabric mask in a few hours.
1) Not a single study has demonstrated that viable Sars-Cov-2 virus survives on porous materials in the real world
2) Even before Covid, it was known for decades (common medical knowledge) that human coronaviruses and flu viruses do not remain viable on porous materials for more than several hours.
That this common knowledge is not so common knowledge among the public is a failure of public health communication. The one or two alarmist studies showing that the virus "survives" X number of days don't reflect the real world because 1) the researchers literally directly douse or soak the surface with a huge viral load, and 2) the researchers usually only look for viral genetic material, not whether the virus can infect cells. Viability != detecting viral genetic material (same story for people - we shed viral genetic material long after we stop being contagious).
I could only find this study on Sars-Cov-2 that cultured the virus (still used a huge viral dose in a lab setting, not the real world). Even though they were able to culture the virus, only 1% of virus remains after 6 hours on a surgical mask, several orders of magnitude less for cotton clothing: https://www.medrxiv.org/content/10.1101/2020.05.07.20094805v...
This long post was originally meant to be a reply to someone asking for a citation; it's yet another example of how much effort is required to combat misinformation.
> On the other hand, transmission of novel coronavirus to persons from surfaces contaminated with the virus has not been documented. Recent studies indicate that people who are infected but do not have symptoms likely also play a role in the spread of COVID-19. Transmission of coronavirus occurs much more commonly through respiratory droplets than through objects and surfaces, like doorknobs, countertops, keyboards, toys, etc. Current evidence suggests that SARS-CoV-2 may remain viable for hours to days on surfaces made from a variety of materials. Cleaning of visibly dirty surfaces followed by disinfection is a best practice measure for prevention of COVID-19 and other viral respiratory illnesses in households and community settings
1) Not a single study has demonstrated that viable Sars-Cov-2 virus survives on porous materials in the real world
2) Even before Covid, it was known for decades (common medical knowledge) that human coronaviruses and flu viruses do not remain viable on porous materials for more than several hours.
That this common knowledge is not so common knowledge among the public is a failure of public health communication. The one or two alarmist studies showing that the virus "survives" X number of days don't reflect the real world because 1) the researchers literally directly douse or soak the surface with a huge viral load, and 2) the researchers usually only look for viral genetic material, not whether the virus can infect cells. Viability != detecting viral genetic material (same story for people - we shed viral genetic material long after we stop being contagious).
There is a reason the CDC has always said surface transmission is rare: https://www.nytimes.com/2020/05/22/health/cdc-coronavirus-to... there have been no documented cases of surface transmission: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si... Fortunately some in the media are catching on to the hygiene (security) theater: https://www.theatlantic.com/ideas/archive/2020/07/scourge-hy...
Citations for 1) and 2):
Most studies use unrealistic starting doses: https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099...
Other human coronaviruses don't survive long on porous surfaces (gone by 6 hours): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7134510/. A hospital randomly collected patient and real surface swabs (including non-porous surfaces) for original SARS, a minority were PCR positive, none of the swabs were infectious (viral culture): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7134510/. Same story for flu (virus can be detected for days, but inactive and not viable after a few hours): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222642/.
I could only find this study on Sars-Cov-2 that cultured the virus (still used a huge viral dose in a lab setting, not the real world). Even though they were able to culture the virus, only 1% of virus remains after 6 hours on a surgical mask, several orders of magnitude less for cotton clothing: https://www.medrxiv.org/content/10.1101/2020.05.07.20094805v...
This long post was originally meant to be a reply to someone asking for a citation; it's yet another example of how much effort is required to combat misinformation.