top of page

Choosing the right mask to protect against Coronavirus (COVID-19)

Updated: May 18, 2020


Coronavirus (COVID-19), unfortunately has impacted our lives and the world at least for now and near term future. But do all of you know how the virus spreads? I thought I did. But living in New York City, I decided to learn more about the virus.

In this article, I want to share what I learned on how Coronavirus spreads and how we can best protect ourselves. Because together, is the only way we can beat this virus.

How does Coronavirus spread?

First, let's look at what's already known based on info from WHO:

  • The disease spreads primarily from person to person through small droplets from the nose or mouth, which are expelled when a person with COVID-19 coughs, sneezes, or speaks.

  • These droplets can land on objects and surfaces around the person such as tables, doorknobs and handrails. People can become infected by touching these objects or surfaces, then touching their eyes, nose or mouth.

  • This is why it is important to wash your hands regularly with soap and water or clean with alcohol-based hand rub.

What about airborne? Can Coronavirus spread as airborne aerosol (spread through air in smaller particle than droplets)? Droplets are fluids when somone sneezes, coughs, or speaks. In a scientific brief published by WHO on March 27th indicated that there is not sufficient evidence to suggest that COVID-19 is airborne. However, experts say that to gather unequivocal evidence will take years.

Recently, the New England Journal of Medicine, the most respected medical journal in US, published a study by researchers at Ecology and Evolutionary Biology department at Princeton showed that Coronavirus can spread as airborne aerosol. Note that the study is still preliminary, and needs to go through extensive peer reviews.

I think the ambiguity is reasonable. Coronavirus is a new disease, and we are still learning about the virus. For example, just 3 weeks ago, we found that the virus can be asymptomatic, and are just starting to observe the virus in our pets. But what does this mean for us just trying to protect ourselves? Dylan Morris, one of the researcher in the study said it well, “It's now clear that aerosol risks are not negligible for everyday people, particularly in poorly-ventilated indoor areas”.

The right mask:

Now that we understand that there is risk that the Coronavirus can be airborne, let’s understand the different types of masks. The masks, ordering by level of protection from most to least: Respirator mask > surgical mask > non-medical mask >= cloth self-made mask.

Respiratory mask

According to (The Center for Disease Control & Prevention) The difference between respirator mask and medical mask are:

  • Respiratory mask can filter out airborne particles and large droplets while surgical mask can only filter out large droplets. Most large droplets are body fluids from sneeze and cough.

  • Respiratory mask are fitted tightly, while surgical mask has a loose fitting.

Respiratory masks such as N95 (US), FFP2 (European), KN95 (China) can filter out 95% of airborne particles, hence the 95 designation. They are considered equivalent products as long as their standards are met. A technical bulletin issued by 3M indicates:

The difference is that they are tested and approved by agencies in different countries. N95 by US NIOSH (National Institute Occupational Safety and Health), FFP2 by EN (European Standard), and KN95 by GB (Chinese national standards issued by the Standardization Administration of China). The same document also indicates the details of each standard and how similar they are. For example, both N95 and KN95 needs to have a filter rate of higher or equal to 95% at flow rate (air flow) of 85. While FFP2 needs to have a filter rate of 94%, but it's tested flow rate is higher at 95:

As a matter of fact, the testing requirements for N95 and KN95 seems to be very similar. You can check out the full document here.

Surgical mask

Surgical mask is approved by FDA. It's designed to be worn by health care professional during surgery or other medical task. Its main purpose is to prevent contamination by liquid droplets from patients. A key requirement is to prevent liquid penetration, even at high pressure, such as human artery puncture during surgery. Hence medical mask can’t prevent airborne disease.

Other mask

Non-surgical mask or self made mask are not tested or approved by any organization. Covering our mouth and nose is certainly better than no cover at all for exhaling or inhaling droplets, but its effects will vary, and its effects definitely less than surgical mask.


Now, let's put it all together. Hopefully, it hasn't been difficult to follow along. While there are studies that showed that Coronvavirus can spread as airborne aerosol, more studies are needed to confirm. Here is my personal opinion:

  • Since you can't rule out the risk of COVID-19 being airborne, if you are going into a crowded closed space, you should consider wearing a respiratory mask.

  • Since you are already going to bear the discomfort of wearing a mask, you might as well go for the one that offers the most protection.

  • Perhaps I am acting on the side of caution, but I would rather do that than feeling sorry later. The risk is just too high. I can't start to imagine the tolls both physically and emotionally that people go through dealing with COVID-19, and hope never have to.

Since N95 are still in high demand, and should be saved for healthcare professionals in the US, here at, we focus on selling N95 equivalent respiratory masks. Our masks meets both European Standard (FFP2 EN149-2001) and KN95 standards (GB 2626-2006). More importantly, because we believe that protecting ourselves is such a basic human right, we are selling these quality masks at the LOWEST price we can. We will also be donating one mask for every 5 sold (You can check out our mission here). If you know any first responders that needs mask, please contact us.

Thank you, I sincerely hope that you have learned to better protect yourself. TOGETHER, we will get through this. Please be safe.

68 views0 comments

Recent Posts

See All


bottom of page