Face Masks - The Facts
In the face of the ongoing pandemic, face masks have become an ubiquitous item. Many types of face coverings are seen on the street, in the shops and in healthcare environments.
But what are the different types of face masks and how do they protect us from infection?
Read on to discover the latest science on face masks….
Why do we wear face masks?
Face masks help to prevent the wearer from inhaling or exhaling harmful particles and droplets and hence help stop the spread of bacteria and viruses.
The SARS-CoV-2 virus itself is tiny – about 0.1 microns in diameter. But it has to hitch a lift on droplets to spread – and they can range from around 0.2 to several hundred microns in size, though usually between 1-10 microns. So, to be effective, face-masks need to stop these droplets.
In addition, face masks may also prevent you from touching your face with your hands, reducing the risk of infection from bacteria and viruses entering your body.
There are many types of face masks and they offer different levels of protection for different settings. Here are the facts you need to know....
Although homemade masks may be useful in some public areas, they have usually not been tested for their filtration efficiency and the wearer should be aware of their limitations.
However, to get maximum benefit from cloth masks they should be multi-layered (ideally 3-4) and made from plain woven cotton or polycotton, at least 100 threads per inch…like heavy, good quality t-shirt or tea-towel material.
They should fit as well as possible, perhaps incorporating a metal strip or pipe-cleaner to allow moulding around nose and stitching that prevents the material stretching which opens up gaps between threads.
The CDC recommends that you wear a cloth face mask when you're around people who don't live with you and in public settings when social distancing is difficult.
Wash or sanitise your hands before putting on your mask.
It needs to cover nose and mouth…..not just sat on or under the chin!
Tie it behind your head or use ear loops and make sure it's snug.
Don't touch your mask while wearing it.
If you accidentally touch your mask, wash or sanitise your hands.
If your mask becomes wet or dirty, switch to a clean one. Put the used mask in a sealable bag until you can wash it.
Remove the mask by untying it or lifting off the ear loops without touching the front of the mask or your face.
Wash your hands immediately after removing your mask.
Regularly wash your mask with soap and water by hand or in the washing machine. It's fine to launder it with other clothes.
Don't use face masks as a substitute for social distancing.
MHRA Regulatory Advice
Face coverings intended for use by the general public in the community are not classified as PPE or medical devices. As such they do not carry a CE mark and should not be sold or donated as PPE or medical devices. Cloth face coverings are which are sold or donated with particulate material 2.5 filters or other hygiene filters, should not claim to give protection against COVID-19, or they will need to comply with the PPE Regulations.
Sale of face coverings or supply to others outside household or family, requires they meet the General Product Safety Regulations 2005 (GPSR).
Surgical (medical) masks
These masks are classified by international standards according to the bacterial filtration efficiency and level of protection they offer in specific environments.
These products are certified under the European Medical Devices Regulation as a Class I device, so they must be CE marked, EN 14683:2019+AC:2019. MHRA-regulated.
these masks should only be used to reduce the risk of spread of infections and are not intended for use by healthcare professionals in medical settings.
Type II, Type IIR: these masks are mainly intended to be used by healthcare professionals in an operating room or other medical settings with similar requirements.
Type IIR masks are certified as splash resistant which means that the wearer is protected against infection from fluid transfer from coughs and sneezes.
MHRA Regulatory Advice
These are mainly intended for health care staff to wear to protect patients during surgical procedures and other medical settings and are Class I medical devices. They must meet the design and safety requirements of the Medical Device Regulations (MDD/MDR) and be CE marked to be sold in the UK.
Protective (PPE) face masks:
Protective masks, unlike surgical masks, are designed to protect the wearer from inhaling infectious agents or pollutants in the form of aerosols, droplets, or small solid particles.
The wearer should be free of facial hair and be fit tested to ensure they provide a sealed fit. A good seal means that pretty much all the air you breathe goes through the filter – you don’t get protection if air enters around the sides of the mask.
However, these masks may not stop the wearer from spreading infection to others.
The EN 149 standard defines three classes of filter efficiency for these masks;
FFP1: ≥80% filtering efficiency
FFP2: ≥94% filtering efficiency
FFP3: ≥99% filtering efficiency
In the current COVID-19 situation, the NHS is stipulating FFP3 in high risk areas and FFP2 in lower risk areas. Masks are classified as single shift use only (marked NR on the product) or as re-usable i.e. more than one shift (marked R on the mask).
These products must comply with the European Personal Protective Equipment (PPE) Regulation. They are a Category III product under the PPE Regulation, so they must bear the CE Marking and a four-digit number identifying the Notified Body certifying it. MHRA-registered.
Mayo Clin Proc 2020 Oct Forgotten Technology in the COVID-19 Pandemic: Filtration Properties of Cloth and Cloth Masks-A Narrative Review Catherine M Clase et al.