Guidance on mask, which one should I buy? Everything you need to know!



  1. For a N95 mask to be qualified as “Protective Face Mask for Medical Use (医用防护口罩)” in China, both NIOSH N95 (USA) and GB 19083-2010 need to be complied with.  

  2. The N90 mask does not meet the standards of Chinese medical protective mask.



N95.  N95 filters at least 95% particles whose diameters are greater than 0.3 μm. Because the average diameter of coronavirus is 0.1 μm and the diameter of carriers (droplet) is 1-5 μm. The total diameter is greater is 0.3 μm. In this way, we say N95 can filter at least 95% coronavirus.  N95 is the general name of the product that complies US NIOSH standards and passes NIOSH review. Of course, the product form 3M is the most famous one.  KN95 masks must mandatorily complies China GB 2626-2006 standards which is equivalent to US NIOSH N95 standard. It is worthy to mention that the similar product in South Korea is  KF94 and it filters 94% coronavirus. In short, N95 is equivalent to KN95, is approximately equivalent to KF 94, FFP2 is equivalent to KF94.

NIOSH and GB2626-2006 also have other protection level standards. They are summarized in the table below along with standards from other common countries.

(Disposable) Surgical Mask / Medical Surgical Mask

As the name self explained, this mask is usually used in surgery and other environments where bodily fluids (including droplet spread) and blood splashes happen. It can block blood and bodily fluids passing through the mask that may contaminate the wearer. As shown in the following figure. It has three layers (three-ply). The outer layer protects against liquid splashes. The filter (middle) layer uses melt-blown electret non-woven material to stop microbes from entering or exiting the mask . And the inner layer absorbs moistures released by the wearer.  In China, surgical mask product must conform to YY0469-2011 standard and the statement of compliance must be shown on the packaging. You can check whether the producer has the compliance certification and if the product is qualified by looking up on the official website of China Medical Products Administration ( Since the surgical mask can block 95% bacteria, prevent spreading droplets and it's way cheaper than N95, it is recommended to use as a regular protection. 

(Disposable) Medical Mask / One-time Use Medical Mask

The medical mask have similar structure and outlook as surgical mask, except it has lower standard. The outer layer has very limited ability to protect against liquid splash. In China, it must comply with the YY/T0969-2013 standard. Medical mask products can also be checked on the National Medical Product Administration website (


Your top 10 FAQ:

Question 1: which mask should I wear?

In public areas where you're not in close contact with a patient who's be diagnosed, surgical mask is good enough.  No need to over-protect, not to mention that N95 is way more expensive. If you will be in close contact with patients, protective mask for medical use such as N95 is needed. If you don’t have surgical mask, a medical mask will also do the job. But masks without certification and unbranded masks are not recommended, unless you have no other choice. 

Question 2: The mask I bought have no producer nor product name. How can I check which category it belongs to?

This is an unbranded face mask. We have no way to check. Avoid these products unless you have no choice. 

Question 3: I don’t speak Chinese. How can I check whether my mask meets the standard or not?

Take a clear picture of your product and its packaging, email them to with the title “Face Mask Product Check”. I can check for you and reply within 24 hrs. 

Question 4: Is N90 better than surgical mask?

Since surgical mask can prevent 95% bacteria while N90 only prevents 90%, surgical mask is better for preventing coronavirus.

Question 5: Why is a mask claimed as medical mask or surgical mask doesn't state that it conforms to certain standards?

Then there is no guarantee for the protection. 

Question 6: Can I wear a mask all the time?

With N95 masks, the wearing time cannot exceed 4 hrs at a time. It may cause lung damage, emphysema or other problems if you wear it for longer than stated time. This is another reason to use surgical mask when you are not in close contact with patients.

Question 7: Choose N95 with valves or without?

Professor WANG Yuedan of the School of Basic Medical Sciences, Peking University, said in an interview that a mask with a vent valve is not recommended for the prevention of coronavirus, because it may cause the virus to accumulate locally. In addition, the contaminated exhalations cannot be blocked when a patient breathes out. However, a valve ameliorates the hardship of breathing when wearing N95.

Question 8: The mask I bought claimed that it meets certain standards, such as N95, medical mask, surgical mask, etc., but I don’t see them marking these standards on the packaging.

Then there is no guarantee.

Question 9: How about cotton mask, active carbon mask, sponge mask , paper mask?

They are not used for preventing the virus.


Repost from

Leave a comment

Please note, comments must be approved before they are published