skip to primary navigation skip to content
Home

Studying at Cambridge

Respiratory Protection Engineering Task Force

 

Frequently Asked Questions 

Questions about Fabric Masks:

Fabric masks

What fabric works best for face masks?

Short Answer: Tightly woven cottons can be one good choice. Layering fabrics also improves the filtration of the mask.

Long Answer: Multiple studies suggest that tightly woven cotton is a good material for homemade face masks. Layering fabrics improve filtration. Make sure any materials you use are easy to breathe through. Using difficult-to-breathe-through fabric will encourage unfiltered air to come through gaps in the mask.

Read the original study
Fabric masks

Will a fabric mask protect me?

Short Answer: Yes - a fabric mask will provide you, the wearer, with some degree of added protection

Long Answer: No study has shown a fabric face mask that, when worn, provides the same degree of protection as an N95 mask. However, fabric face coverings do indeed protect the wearer in a variety of ways! Firstly, the fabric mask will filter some percentage of particles from the air. Our studies found fabric masks blocked upwards of 40% of particles from the air, with multilayered masks or masks with PM2.5 filters achieving over 70% filtration. This reduces the number of potentially harmful particles you are inhaling. With a fabric face mask, there is a reduced chance that the harmful particle be inhaled. Even if you inhale pathogenic particles, it is likely that you will inhale fewer of them. While it is only theory at this point, many doctors believe that the amount of virus or pathogen you receive impacts whether you get sick and, if you do get sick, how quickly and severely you get sick.

Questions about Clinical Masks:

Mask Types

Should I use clinical grade masks? 

Short Answer: Non-clinical grade masks are recommended for use by the general public. Fabric masks, surgical masks, and KN95 are all options to consider. N95 and FFP3 masks are only recommended for use by clinicians in high risk environments or for those who are extremely vulnerable. They should not be used by the general public as long as supply chain problems continue.

Long Answer: There are unprecedented pressures on the supply chains of N95 and FFP3 masks. They are recognised as having better fit and filtration efficiency than non-clinical grad face coverings, though they are also more expensive and require fit testing before use to provide high levels of protection. They are only recommended for use by clinicians or those who are extremely vulnerable. Fabric face coverings have been recommended by the UK government, US government and World Health Organisation. If you feel you need more protection, consider an FFP2 or KN95 mask. Read our study on testing the fit of KN95 and FFP2 masks.

N95 Masks

How can I be sure my N95 mask is legitimate?

Short Answer: There have been reports of counterfeit N95 masks being sold. Obtain your N95 mask from a reputable source and check the information printed on the facepiece to ensure it matches NIOSH records.

Long Answer: In the USA, N95 masks are regulated by the National Institute for Occupational Health and Safety (NIOSH). NIOSH conducts a series of tests on each respirator model to assess its fit, filtration efficiency, breathing resistance, and, if applicable, valve leakage. Based on the results of these tests, NIOSH certifies a face mask with a classification such as N95. A full NIOSH approval label should be contained in every box of face masks, with an abbreviated approval label printed onto the facepiece itself. Both will include the “fit and certification” testing approval number and manufacturer. You can look up the approval code on the NIOSH website to make sure it matches the mask’s design and make. There is always the risk a particularly devious manufacturer might illegally plagiarize a NIOSH approved mask.

Study at Cambridge

About the University

Research at Cambridge