Different face masks explained

• Folded Masks are lightweight in design and offer a close fit to the face using elasticated head straps, usually clipped over your ears or tied at the back of the head, but they do not provide a perfectly flush fit.

• Moulded Masks offer the closest fit of all mask types and fit snuggly to your nose and mouth covering the chin. These are the most effective style of mask as they minimise the risk of particles arriving in your respiratory system.

• Unvalved Masks have the filtration system built into the fabric of the mask which makes the masks lightweight, comfortable and easy to wear for long periods of time.

• Valved Masks tend to be slightly bulkier than unvalved masks but the valve allows air to pass out of the mask safely which can make them more breathable and comfortable (less sweaty) over time.

Grading of face masks

Below we've highlighted the information you need to help you decide which face masks to buy as it can be confusing with all of the different types and ratings.

Face masks generally fall into three categories;

• Single Use Face Mask (normally one layer, very thin) are typically effective at capturing larger dust particles, but can do so fairly well and should meet the Bacteria Filtration Efficiency Standard (BFE) which means they should capture >95% of microns 3.0 or larger. They are not suitable for blocking particles of 0.1 microns. We are not currently supplying these masks from this website.

• Surgical Face Mask standards have higher requirements for capturing virus-sized (0.1 micron) particles, however the ratings vary by region. Our surgical face masks meet the following standards for EN14683 / ISO13485 / CE which fall into 3 categories, namely;

• Type I  3.0 microns >95% 0.1 microns no rating
• Type II 3.0 microns >98% 0.1 microns no rating
• Type III 3.0 microns >98% 0.1 microns no rating

• Respirator Face Mask typically capture >90% of virus-sized particles and  their ratings vary by region. The ratings for Europe EN149: 2001 (FFP2) require a very slightly different level of performance than the ratings used for China/USA. As an example a KN95/N95 mask is tested to block >95% of 0.3 micron particles vs an FFP2 mask which is tested to block >94% of 0.3 micron particles.

What are the different ratings for Respirator face masks?

The ratings for face masks for Europe conform to EN149: 2001 and are graded FFP1, FFP2 and FFP3. This reflects a number of tests the masks must pass to reach the differing grades. These include the quantities of particles/size of particles that are allowed to pass through them.

The ratings for face masks in China conform to standard GB2626 and are graded KN95, KN99 and KN100 whilst the US uses the N grading i.e. N95, N99, N100.

What other tests and ratings are there for face masks?

There are other tests including flow rates and leakage test that mask manufacturers have to pass and our research shows the KN95 test for China is a little stricter in terms of the volume of particles passing through them than the tests for N95 rated masks, however on the flip side flow rates for KN95 rated masks are lower. Flow rates affect the breathability of the masks and N95 masks have slightly stricter requirements for pressure drop while inhaling.

That means they’re required to be slightly more breathable than KN95 masks. N95s also have slightly stricter requirements for pressure drop while exhaling, which should help with breathability.

N95s and KN95s are both rated to capture 95% of particles, although only KN95 masks are required to pass fit tests. N95 masks have slightly stronger requirements for breathability.

In addition the Chinese government requires manufacturers to run mask fit tests on real humans with ≤ 8% leakage required for the KN95 rating. 

Conclusion

The advice for which type of masks you should wear is very mixed. It is understandable, after all governments want to protect their health service staff first, and rightly so in our opinion. To do this they have to ensure that enough medical grade masks reach frontline staff.

This means masks for key workers and care staff by default becomes a lower priority. Equally the use of medical grade masks for members of the puiblic by default becomes an even lower priority. This does not mean members of the public should not waer them, or they are not effective, it just means governments cannot make them a priority for the public right now.

Our advice is you must draw your own conclusions and do what is right for you and your loved ones. Whilst we appreciate the need to make the NHS a priority, care workers and other key workers should be a priority too.