There are a lot of ways to stop the spread of the coronavirus. Social distancing measures and the use of proper hygiene (like hand washing) have proven to be somewhat useful. But it seems the most important measure used to combat the spread of this virus is masking up. Masks have been proven to slow the spread of coronavirus considerably and are a surer bulwark against the virus than any measure.

We all know that coronavirus spreads through droplets released during coughing or sneezing. While some studies say that coronavirus could also be spread through gaseous release, there has been no evidence that this is an important medium through which the virus is spread. Face masks stop the spread of the majority of these droplets, and they also prevent these droplets from landing on the face of others. These facemasks are more effective in preventing the droplets from leaving the face of the infected. So, for the most part, you wear facemasks to stop yourself from infecting others. 

This year has seen a surge in the importance of masks to the everyday person. In fact, this year may have seen the highest sale of masks worldwide. Every country, every state, and every municipality is ordering them by the bucketload. It doesn't look like that would stop anytime, either. 

Since the beginning of the coronavirus pandemic, masks (of different kinds) have become more critical than they've ever been. More of them have been sold and produced than perhaps anytime in our history. But the race to get masks (or to get masked) also has an important aspect. 

There are a lot of different mask types. And some are better than others. It's no surprise that the question of which masks should be used and when they should be used arose.

Several kinds of face masks have been used by people. Some people have used bandannas. Others have used homemade face masks, while some have used the highly rated ASTM level three masks. In this article, we'll be looking at what these face masks are, what level of protection they provide, and finally, the difference between the ASTM level three masks and other kinds of masks. We'll also be comparing the ASTM level 1 vs 3 masks.

Before we go on, you should know that People can get ASTM level 3 face masks online. 

Types Of Facemasks 

T-Shirt Mask

If you go online, you will find many tutorials teaching you how to turn old T-shirts into masks. And this may seem smart. After all, the t-shirts are cheap, and almost everyone has an old cotton T-Shirt at home. 

 But exactly how effective are these masks? Well, the answer is not very useful. According to a 2013 study, t-shirt masks are only one-third as effective as disposable surgical masks. If this is so, why do people continue to use masks made from t-shirts? Well, they are very comfortable, for one. The slightly stretchy material fits around the face in a relatively relaxed way, and it looks good. 

Many people have tried going down the rabbit hole of making t-shirt masks more effective, but they've not found a lot of success. The 2013 study discovered that adding another layer to the mask didn't do too much to prevent bacteria— however, it made it even more difficult for the wearer to breathe. 

Store-Bought Clothes Mask

Different kinds of store-bought masks, and the effectiveness of this kind of mask mostly depends on its construction. 

According to several health institutes, you should look out for masks that have three layers of fabric, and  they should be constructed from tight-weave 100% cotton cloth. These kinds of masks may offer up to 50% protection. Sadly, that's as high as cloth masks can offer. If you want better protection, you would have to buy surgical masks that offer higher level protection.

Homemade Cloth Mask

A single layer cloth mask may only provide about 1% particle filtration. However, a two-layer cotton mask may filter up to 35% of small particles. Asides that, these masks can reduce the reach of droplet sprays from 8 feet to 2 1/2 inches. 

Like store made masks, the effectiveness of homemade cloth masks depends on how they are constructed. According to John Hopkins Medicine, the best materials for these kinds of masks are densely woven cotton fabrics. Additionally, single layer fabrics are less effective than double-layered fabrics. Double layered fabrics may also be less effective than double layer fabrics.

It's important to note, though, that filtration isn't the only factor to consider when choosing a mask. There are other important factors, and one of them is breathability. 

Disposable Surgical Mask

Disposable surgical masks are those paper-like masks that are usually white and light blue. According to a 2013 study, these masks are more effective than regular face masks and may filter up to 60% of small particles. These masks were made to stop droplets, splatters, and sprays from touching the face. Many studies have shown that wearing this mask in public places can significantly reduce catching respiratory infections like Covid-19. 

The thing about these masks is that they are not meant to be used more than once. They need to be disposed of after single use.

ASTM Level three masks and other respirators

First off, what are ASTM level three masks? These masks are masks that reach level three of the ASTM mask standards. 

ASTM is a private nonprofit organization that publishes consensus technical standards for a wide range of systems, materials, products, and services. And one of the products that ASTM publishes standards for is face masks. Before the FDA approves any face mask, it has to meet and be classified according to ASTM standards. ASTM has three mask standards, and they are level one, level two, and level three. 

Level one masks provide short-term or low-level protection against bacteria, viruses, and fluids. These masks are the general standard for both procedural and surgical use. 

Level two masks offer moderate protection against aerosols, sprays, or fluids. And Level three masks provide the highest level of protection against these substances. 

Level three ASTM masks offer up to 98% protection against different aerosol levels, sprays, or fluids. These masks offer the highest form of protection that can be found anywhere. That's why they are usually worn by most people at the front lines of managing epidemics like doctors and nurses. They are often worn during surgeries as well because they protect from high-pressure sprays. 

Surgical Masks Vs. Homemade Face Masks

Of all these face masks, two are very common, and they are surgical masks, and homemade face masks. How do these two masks compare in terms of effectiveness? 

The first thing to know is that both surgical masks and homemade masks offer some level of protection from germs. They do this by stopping the spread of germs by the wearer of the masks. Surgical masks have standards that they must meet (the ASTM standards, for example) and thus are better designed for protection, breathability, and fit. 

Homemade masks are not like this. They have a different structure, are made with other materials, and, most importantly, they don't have to meet any standards. 

Homemade masks are especially good at giving some level of barrier protection against large droplets. Thus, they also offer the wearer some protection— even if it's only against droplets that are too big to pass through the mask. This mask's real defense is that it stops sick people (or asymptomatic people carrying the virus) from spreading it. If a Covid patient is wearing a homemade mask, they won't be able to spread the virus quickly— even when they are coughing. 

What Standards Are There For Surgical Masks

One of the most critical differences between surgical masks and homemade masks is that surgical masks have standards that they must meet. These standards are published and set by the ASTM, a private organization that publishes safety standards for all sorts of products. Any mask that must be approved by the FDA must reach standards set ASTM.

The ASTM has three set levels that masks must reach before they are approved. These are the level one, level two, and level three stages. With these classifications, it's easy to understand the level of protection that a certain mask can offer, and it would be easier to understand what conditions to use it. 

How Does The ASTM Level Three Mask Compare To Other Masks

Simply put, ASTM level three masks offer the highest level of protection that can be gotten from masks. That's why doctors usually use these masks in operating rooms or on the front lines of fighting infectious diseases. 

ASTM level three masks have to go through five types of testing in order to be certified. The tests are as follows.

  • Fluid Resistance
  • Particulate Efficiency
  • Flammability
  • Biocompatibility
  • Differential Pressure
  • Bacteria Filtration Efficiency

Fluid Resistance

The fluid resistance test measures the mask's ability to stop or outrightly minimize the fluid level that can pass through the mask's construction. The testing is carried out with synthetic blood sprayed at different levels of pressure. The first level is at 80 mm Hg, which is just about the blood pressure of the venae cavae. Level two is pumped at 120 mm Hg, which is the arterial blood pressure. And level three is sprayed at 160 mm Hg which happens to correlate with the potential high-pressure spraying that could occur during surgeries that require high-pressure irrigation. Level three masks must be able to withstand fluid sprayed at 160 mm Hg

Particulate Efficiency

The Particulate Filtration Efficiency Test measures how well the mask can filter through extremely small particles. These particles are at the sub-micron level, and are meant to be a good test of how the mask can filter viruses. The higher the percentage of the particles that can be filtered (or stopped), the better the mask. ASTM level two and three masks must have 98% particulate efficiency while ASTM level one masks must have about 95% efficiency. 


All ASTM masks must be made with class one inflammable material. 


All ASTM rated masks, regardless of level, must be biocompatible with human skin. The material used in making the masks must be harmless to the wearer. 

Differential Pressure

Differential pressure, as known as Delta P, measures the breathability of the mask. No matter how great a mask is, it must be breathable to have any use. The Delta P of any mask is measured in units of mm H2O/cm2. In this test, the lower the value, the more breathable the mask is. ASTM standards specify that level one masks must have a Delta P of around 4.0, while level two to level three masks must have a Delta P of about 5. 

You may be wondering why ASTM level two and three masks have to reach lower standards than level one masks. That's because level 2 and 3 masks have more robust construction, and as such, will not be as comfortable as level one masks. Since level one masks aren't that strong construction-wise, they are meant to be more comfortable. 

Bacteria Efficiency Test

This test is used to measure how well the mask can filter bacteria. To test this, the mask in question is challenged with bacteria-containing aerosol. All masks must have a minimum 95% filtration rate to even be called surgical masks, and level two and three masks must have a 98% filtration rate. 

These stringent testing and certification methods are precisely what stands ASTM level three surgical masks out from other kinds of masks. These masks cannot offer the level of absolute protection that ASTM level three masks provide.