With the corona virus outbreak in China, many people are understandably concerned about their health and safety. Masks offer a first line of defence for filtering out airborne particles – which may be particularly useful in crowded spaces such airports, hospitals etc.
In this post we’ll look at the difference between mask filtering standards such as N95 and FFP2/FFP3…
- 1 Masks vs Respirators
- 2 Respirator Standards
- 3 Fluid Resistance? Surgical Masks?
- 4 Reliable Brands?
- 5 Is Eye Protection Necessary?
- 6 Related Questions
- 7 Roundup
Masks vs Respirators
Before we go any further, lets just clarify on a technical difference between a “mask” and a “respirator”. In day to day language we often say mask, when referring to what are technically called respirators.
Uses for Masks:
- Masks are loose fitting, covering the nose and mouth
- Designed for one way protection, to capture bodily fluid leaving the wearer
- Example – worn during surgery to prevent coughing, sneezing, etc on the vulnerable patient
- Contrary to belief, masks DO NOT protect the wearer
- The vast majority of masks do not have a safety rating assigned to them (e.g. NIOSH or EN)
Uses for Respirators:
- Respirators are tight fitting masks, designed to create a facial seal
- Designed for two way protection, by filtering the air breathed in
- These DO protect the wearer (when worn properly), up to the safety rating of the mask
- Available as disposable, half face or full face
Whilst surgical style masks are not redundant by any means, they’re not ideal in the case of a highly transmissible airborn virus, because they don’t filter out small particles, such as viruses. To do this we need a respirator with adequate safety rating.
The US Center for Disease Control (CDC) cites the N95 respirator standard as part of the advised protective equipment in their 2019-nCoV FAQ and their SARS guidance (SARS being a similar type of Corona virus). Which suggests that N95 or better is acceptable.
N95 vs FFP3 & FFP2
The most commonly discussed respirator type is N95. This is an American standard managed by NIOSH – part of the Center for Disease Control (CDC).
Europe uses a “filtering face piece” score (FFP). This comes from EN standard 149:2001 – drafted and maintained by CEN (European Committee for Standardization). Let’s see how they compare:
|Respirator Standard||Filter Capacity (removes x% of of all particles that are 0.3 microns in diameter or larger)|
As you can see, the closest European equivalent to N95 is an FFP2 (also referred to as P2) rated respirator, which is rated at 94%, compared to the 95% of N95. Likewise, FFP3 (P3) rated respirators are most comparable to N100.
You could (over)simplify things to say:
Are N95/N100 better than FFP2/FFP3?
Actually, no. It’s important to note that these standards only specify the minimum % of particles that the respirator filters. For example, if a mask is FFP2 rated, it will filter at least 94% of particles that are 0.3 microns in diameter or larger. But in practice it will filter somewhere between 94% and 99%. The precise figure will often be quoted by the manufacturer in the product description.
N vs P respirators?
The CDC explains that in the USA there are 3 ratings for protection against oils; N, R or P:
- N = Not resistant to oil
- R = somewhat Resistant to oil
- P = strongly oil Proof
What this means in practice, is for industrial settings, where the air might contain a lot of oil particles, if the mask isn’t P rated, then over time the oil may degrade and reduce the filter performance.
For the vast majority of people trying to reduce exposure to 2019-nCoV, it won’t be necessary to protect against oils – this is primarily designed for industrial use settings.
Fluid Resistance? Surgical Masks?
Alongside “regular” respirators, there are also what are often referred to as “surgical” or “surgically approved” respirators. These carry the aforementioned ratings such as N95/FFP2, but are also approved for fluid resistance. A qualification governed by ASTM F1862 – which covers the edge case in which an artery is punctured, and high pressure blood is sprayed directly at the respirator. To pass the test, the mask has to withstand this spray without leaking fluid inside the mask.
You can see why this type of mask if important for surgery, but it’s not clear outside of that setting how much extra benefit it would provide. Regular N95/FFP2 masks will block things like coughs and sneezes.
The comparison table below shows how a regular N95 mask (8210), stacks up against 2 surgical N95 masks (1860 and 1870+).
Example of Surgical vs Non-Surgical Masks
See this comparison table below for the key differences (source: 3M website):
|N95 Respirator 3M Model 8210||Surgical N95 Respirator 3M Model 1860||Surgical N95 Respirator 3M Model 1870+|
|Designed to help protect the wearer from exposure to airborne particles (e.g. Dust, mist, fumes, fibers, and bioaerosols, such viruses and bacteria)||✅||✅||✅|
|Designed to fit tightly to the face and create a seal between the user’s face and the respirator||✅||✅||✅|
|Meets NIOSH 42 CFR 84 N95 requirements for a minimum 95% filtration efficiency against solid and liquid aerosols that do not contain oil||✅||✅||✅|
|Cleared for sale by the U.S. FDA as a surgical mask||❌||✅||✅|
|Fluid Resistant - Meets ASTM Test Method F1862 “Resistance of Medical Face Masks to Penetration by Synthetic Blood” which determines the mask’s resistance to synthetic blood directed at it under varying high pressures||❌||✅ 120 mm Hg||✅ 160 mm Hg|
According to the 3M wesbite:
 "ASTM F1862 is a standard test method for resistance of medical facemasks to penetration by synthetic blood. This test is required because during certain medical procedures, a blood vessel may occasionally be punctured, resulting in a high-velocity stream of blood impacting a protective medical facemask. The test procedure specifies that a mask or respirator is conditioned in a high-humidity environment to simulate human use and is placed on a test holder. Synthetic blood (2cc) is shot horizontally at the mask at a distance of 30 cm (12 inches).
Surgical masks and respirators are tested on a pass/fail basis at three velocities corresponding to the range of human blood pressure (80, 120, and 160 mmHg). The inside of the mask is then inspected to see if any synthetic blood has penetrated to the inside of the facemask. Fluid resistance according to this test method is when the device passes at any level."
In essence, all 3 of these masks should be adequate, as per CDC guidance on 2019-nCoV and SARS. As mentioned above, where the 1860 and 1870+ are superior to the 8210 is when faced with high velocity liquid spray - which is possible during surgery (e.g. punctured artery), but unlikely in day-to-day usage.
For those outside the UK or USA, look for brands that carry ratings appropriate to your country. For example in China they have a rating standard called LA, which I believe is based on specification in GB 2890-2009.
Is Eye Protection Necessary?
Whilst the coronavirus can’t penetrate skin, it can penetrate all exposed mucous membranes, which includes the eyes.
This is why you often see medical professionals wearing eye masks when in contact with infected patients.
That said, eyes are presumably a lower risk as a route of entrance, compared to the mouth, which is constantly breathing air directly into the lungs.
For eye protection, there are two routes you can go down; one is a disposable respirator and safety goggles, the other is a full face respirator. Safety goggles with a rubber air seal are preferential. Bollé make some minimalist models which include a rubber seal, and can be found on Amazon.
Why do we see Chinese wearing masks instead of respirators?
It’s not 100% clear why there have been so many pictures of Chinese wearing masks rather than respirators. If I had to guess I’d imagine it’s a combination of:
- Equipment access – early on there may have been shortages of respirators, so they resorted to what was available (masks)
- Education – it may have taken time for awareness to build up over the need for N95 or better respirators
- Comfort – masks are generally more comfortable to wear than respirators for long periods of time
Are surgical masks completely useless?
No. Whilst respirators are ideal, surgical masks still perform some useful tasks in the context of virus protection. Perhaps crucially, they block the ability to put our hands on our face (mouth and nose in particular). According to one study, we touch our face on average 15x per hour. Therefore if we can avoid picking up pathogens from the environment on our hands, then transferring them to our faces, that is a net positive.
Where surgical masks fall down is their ability to filter the air that we breathe in.
What else can you do?
Regular hand washing/sanitizing
– Especially after you’ve been out, and prior to eating.
Sanitize your phone
– Given how often we use our phones, this seems like the next logical priority to be sanitized. Using antibacterial wipes to clean your phone and other items is a good option. Look for wipes that claim to be able to kill the flu virus (H1N1) – as that’s a good sign they may be able to do similar for the coronavirus.
Sanitize other items you touch regularly
– This includes:
- Computer keyboard and mouse
- House and car keys
- Re-usable water bottles
- Car steering wheel
- Clothing pockets
- Door handles
Note that there will be a difference between a small amount of a virus that has been transferred to an item you touch, and spending significant time in the presence of someone who is actively shedding the virus. With the latter, the disease burden will be greater, and will make it harder for our immune system to defend against. But that doesn’t mean we should overlook the former either.
Reduce the amount of times you touch your face
– Whilst it’s easier said than done, being aware of how many times we touch our faces each day (discussed above) should help some way to reducing this.
Keep your immune system healthy
– This is a big topic on its own – but I do plan to write about it. Suffice to say this is also important, and we definitely don’t want to run down our immune system right now.
Hopefully if you’ve stumbled across this article, and you were confused about the difference between N95 and FFP2/FFP3 masks, this has cleared things up for you.
If you have any further questions, please leave them below in the comments.