Due to the ambiguous and conflicting nature of the little information we do have on the effectiveness of wearing a form of mask in order to reduce the spread of COVID-19, many food businesses have reached out to us with questions over the use of PPE in the workplace as employees start looking to return to work. There is little information on the efficiency and efficacy of masks regarding their ability to filter out respiratory virus particles, such as coronavirus; yet over 30 countries have made masks a legal requirement outdoors for the public. So this naturally begs a question: Is there a significant benefit in using some form of face covering for warding off this virus?
Firstly, in order to decide on their effectiveness, let’s look at the different types of commonly used masks and their intended purposes.
- Surgical Masks: A disposable, multilayer mask intended to act as a barrier to protect surgical personnel and general health-care workers, as well as patients from splashes of blood, body fluids and large droplets.
- N95 Respiratory Masks: Manufactured mainly for industries that expose employees to dust and other small particles, although some are designed for use in health care. As the name might suggest, this mask is designed to block 95% of very small particles, making them more protective than a surgical mask.
- Cloth Masks: Since medical masks are discouraged for public use so as to preserve the limited supply for medical professionals, many have come to make their own out of fabric. Said to be less effective due to their porosity and often found gaps between the nose, cheeks and jaw area.
- Plastic Face Shields: Used by many workers usually not used alone, but along with other forms of PPE.
Although there have been no significantly large scale clinical trials, studies have been made on different types of masks but neither tell us that masks are useful or just a waste of time. A certain study carried out in South Korea1 took four patients infected with coronavirus asking them to cough into separate petri dishes five times while wearing a sequence of masks along with no mask, each time. The result was that neither surgical nor cotton masks effectively filtered out SARS-CoV-2. It is worth noting that they did find greater contamination on the outer layer as opposed to the inner surface of the mask which may be due to air leakage around the mask’s edge which may have led to the outer layer’s contamination. Another study taken at the University of Edinburgh2 on 7 different face coverings including medical and homemade masks, proved that the surgical and homemade masks tested did help reduce the distance in which the micro droplets spread forward but did generate far reaching jets of air leakage to the side, behind, above and below especially in heavy breathing and coughing. Only the masks that formed tight seals around the face were found to prevent the escape of particles.
To sum up, due to the fact that most masks, especially homemade masks, are so porous and coronavirus particles so small, that while they may protect against larger droplets from a cough or sneeze, they do not act as a physical barrier. If you were to magnify under a microscope, the pores on a mask are as effective as chicken wire is to prevent dust particles from entering.
Advantages:
- Proper PPE can help protect others if you are infected.
- Studies show that the combination of wearing a mask and hand washing is more effective than hand washing alone.
- Surgical masks reduce the amount of seasonal coronavirus particles.
- Fabric masks may catch larger particles droplets such as from a cough or sneeze.
- Psychologically, it may provide a sense of security and peace of mind for some.
Disadvantages:
- No solid evidence to prove that it is significantly beneficial to wear.
- Masks are not likely to protect the wearer.
- It can increase your own risk of exposure because of possible mishandling of a contaminated mask.
- The most readily available masks, homemade masks, are a lot less effective.
- They MUST fit well with very few gaps in order to work well.
In summary, mask wearing may just be an extra add-on precaution. For some, they may just be helpful so as to provide a feeling of safety and security. Regular and thorough hand washing, as well as social distancing are still predominantly the best and most effective way of staying safe. There is no point in wearing a mask or another form of PPE if you are neglecting these most vital procedures. We cannot put our faith in face covering to get us back to normal. It is absolutely vital, more than ever, that proper and continuous hand hygiene is maintained during this time.
For help and advice on keeping you and your customers safe during this time, please contact us.
References:
- https://www.acpjournals.org/doi/10.7326/M20-1342
- https://www.ed.ac.uk/covid-19-response/latest-news/face-coverings-covid-19-transmission-risk