https://www.gov.uk/government/publications/how-to-wear-and-make-a-cloth-face-covering/how-to-wear-and-make-a-cloth-face-covering
I didn't go looking for it it was sent in a document by the Care Home company I work for. My issue with it is, neither the Government or the Care Home Company added any information as to the efficiency or not of masks made out of T-Shirts. Nor as to the density of the fabric that should be used. Will we see string vest type masks? I know that's going to the extreme but we've already had people wearing G-Stings as masks. This scant information does nothing to dissuade that.
My other point is, this information is now being disseminated within Care Homes. This could lead to workers believing that this type of basic mask is as efficient as a medical mask. You might think that's ridiculous but there is no information to say otherwise. And it's official, it's on the Government web site, people have a habit of believing such information without investigating much.
Personally, I think it's irresponsible to put up such information without at least a line saying something like "Health Care workers should always use the correct PPE and not homemade versions, unless as a last resort."
Research on T-Shirt masks is scant but I've pulled out some conclusions and comments from Scientific reports and articles below. Obviously read the full document to see the full reports. Scientific reports at the top running down to media-based reports.
In summary, the answer to the question "Do T-shirt masks work" seems to be
- It's better than nothing.
- Doesn't protect the wearer.
- May have some benefit in protecting others if in confined spaces. (Like the tube)
- May have some benefit in protection others if you are coughing or sneezing. (In which case you shouldn't be leaving your house)
- Need to be put on and taken off correctly.
- Need to be washed after each use at temp over 60 degrees. But general detergent will kill the virus.
- Store used face coverings in a sealed plastic bag until they can be washed.
- There are a lot of maybe's and possibles.
The Government webpage says
You should wash a face covering regularly. It can go in with other laundry, using your normal detergent.
Every other piece of information I've read says you should only use a face-covering once before washing it.
Another thing that irritates the hell out of me is conflicting information from Government sources, but hey ho, on we go.
https://www.ncbi.nlm.nih.gov/pubmed/24229526
CONCLUSION:
Our findings suggest that a homemade mask should only be considered as a last resort to prevent droplet transmission from infected individuals, but it would be better than no protection.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7108646/
Conclusion
A protective mask may reduce the likelihood of infection, but it will not eliminate the risk, particularly when a disease has more than 1 route of transmission. Thus any mask, no matter how efficient at filtration or how good the seal, will have minimal effect if it is not used in conjunction with other preventative measures, such as isolation of infected cases, immunization, good respiratory etiquette, and regular hand hygiene. An improvised face mask should be viewed as the last possible alternative if a supply of commercial face masks is not available, irrespective of the disease against which it may be required for protection. Improvised homemade face masks may be used to help protect those who could potentially, for example, be at occupational risk from close or frequent contact with symptomatic patients. However, these masks would provide the wearers little protection from microorganisms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.
https://bmjopen.bmj.com/content/5/4/e006577
Conclusions This study is the first RCT of cloth masks, and the results caution against the use of cloth masks. This is an important finding to inform occupational health and safety. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.
https://bmjopen.bmj.com/content/5/4/e006577.responses?
Critical shortages of personal protective equipment (PPE) have resulted in the US Centers for Disease Control downgrading their recommendations for health workers treating COVID-19 patients from respirators to surgical masks and finally to home-made cloth masks. The study found that cloth mask wearers had higher rates of infection than even the standard practice control group of health workers, and the filtration provided by cloth masks was poor compared to surgical masks. At the time of the study, there had been very little work done in this space, and so little thought into how to improve the protective value of the cloth masks. Until now, most guidelines on PPE did not even mention cloth masks, despite many health workers in Asia using them.
Health workers are asking us if they should wear no mask at all if cloth masks are the only option. Our research does not condone health workers working unprotected. We recommend that health workers should not work during the COVID-19 pandemic without respiratory protection as a matter of work health and safety
It is important to note that some subjects in the control arm wore surgical masks, which could explain why cloth masks performed poorly compared to the control group. We also did an analysis of all mask wearers, and the higher infection rate in cloth mask group persisted.
Finally for COVID-19, wearing a mask is not enough to protect healthcare workers – use of gloves and goggles are also required as a minimum, as SARS-CoV-2 may infect not only through the respiratory route, but also through contact with contaminated surfaces and self-contamination.
Governments and hospitals should plan and stockpile proper disposable products such as respirators and surgical masks to ensure the occupational health and safety of health workers. This appears to have been a failure in many countries, including high income countries.
An improvised face mask should be viewed as the last possible alternative if a supply of commercial face masks is not available, irrespective of the disease against which it may be required for protection. Improvised homemade face masks may be used to help protect those who could potentially, for example, be at occupational risk from close or frequent contact with symptomatic patients. However, these masks would provide the wearers little protection from microorganisms from others persons who are infected with respiratory diseases. As a result, we would not recommend the use of homemade face masks as a method of reducing transmission of infection from aerosols.
The evidence from these laboratory filtration studies suggest that such fabric masks may reduce the transmission of larger respiraory droplets. There is little evidence regarding transmission of small aerosolized particulates of the size potentially exhaled by asymtomatic or presymtomatic indivuidulas with COVID-19.
Can face masks help prevent the spread of coronavirus disease 2019 (COVID-19)?
Yes, face masks combined with other preventive measures, such as frequent hand-washing and social distancing, help slow the spread of the disease.
So why weren't face masks recommended at the start of the pandemic? At that time, experts didn't yet know the extent to which people with COVID-19 could spread the virus before symptoms appeared. Nor was it known that some people have COVID-19 but don't have any symptoms. Both groups can unknowingly spread the virus to others.
https://www.sciencenews.org/article/covid-19-can-fabric-cloth-masks-stem-coronavirus-spread
In one study, a mask that used 16 layers of handkerchief fabric was able to filter out 63 percent of 300-nanometer-sized particles. (The coronavirus is between 50 to 200 nanometers in diameter.) But that mask was harder to breathe with compared with thick, tight-fitting N95 respirators, often used in hospitals, that can block minuscule particles. Wearing a cloth mask with that many layers would be uncomfortable and may “cause some to pass out,” the researchers wrote in the letter.
https://www.bbc.com/future/article/20200504-coronavirus-what-is-the-best-kind-of-face-mask
A cotton bandana was the least effective, followed by a woolen scarf, but a 600-thread-count pillowcase folded four times could filter out around 60% of the particles.
Other researchers have found that while pulling a t-shirt up over your nose and mouth will block less than half of the aerosols coming towards it, doubling and even tripling the layers of a cotton t-shirt fabric can dramatically improve things in an emergency. Other fabrics such as silk and polyester were also found to be surprisingly effective. Cotton flannel, felted wool and quilting cotton have been found to be particularly good at blocking ultrafine particles, and one study suggested that a single sock, when flat and pressed tightly against the nose and mouth, could also serve as a good emergency mask substitute.
Much like the disposable N95 and surgical masks, homemade varieties like these are really only good for one use before they need to be disinfected if you want to maximise their potential. The US CDC recommends routinely washing homemade masks. Hot water alone may not be enough – one recent study found the Sars-CoV-2 virus can survive temperatures of at least 60C. Fortunately, the oily envelope that encases coronaviruses can be pulled part by soap and household detergent.
But Mueller warns that all these alternatives cannot be seen as replacements for an N95 mask. “There is a very important question – for health officials to interpret from the data that we are collecting – about what level of particle filtration is 'safe enough'? It is unfortunate but true that in some cases people may be choosing between multiple imperfect options.”
What about homemade masks?
As NPR has previously reported, some research has shown that cotton T-shirt material and tea towels might help block respiratory droplets emitting from sick people — though it's not clear how much protection they provide.
Another study, of health care workers in Vietnam, found that use of cloth masks resulted in greater infection than either those wearing surgical masks or a control group, some of whom also wore surgical masks.
https://www.bbc.co.uk/news/health-51205344
The World Health Organization (WHO) currently says only two groups of people should wear protective masks, those who are:
Sick and showing symptoms.
Caring for people suspected to have coronavirus.
It says medical masks should be reserved for healthcare workers.
Masks are not generally recommended for the public because:
they can be contaminated by other people's coughs and sneezes, or when putting them on or removing them.
Frequent hand-washing and social distancing are more effective.
They might offer a false sense of security
But that doesn't mean they have no benefit at all for the general public - it's just that the scientific evidence is weak.
Homemade cloth face-coverings can help reduce the risk of transmission in some circumstances - they might help stop the spread of coronavirus by people who are contagious but have no symptoms (known as asymptomatic transmission).
The most protective mask is an FFP3 or, alternatively, an N95 or an FFP2. NHS staff in lower-risk situations can wear a surgical mask. This includes healthcare workers within one metre of a patient with possible or confirmed Covid-19. These staff may be in hospitals, primary care, ambulance trusts, community care settings and care homes.
OTHER LINKS
