The purpose of a face covering is to protect the wearer’s airways from the airborne transmission of infectious diseases. However, it is crucial to remember that each face cover is designed with a specific application and that not all types of masks or coverings offer the same level of protection.
Three of the most common ways to protect your nose and mouth from airborne infections are the 3-ply disposable mask, the N95 (or KN95) mask, and the cloth mask. Find out more about the characteristics of each type, their differences, and their intended applications to determine the right face mask for you.
3-Ply Disposable Face Masks (Surgical Masks)
A 3-ply disposable face mask is a surgical mask designed for use in healthcare environments. It is a type of facial personal protective equipment (PPE) commonly employed by nurses, surgeons, and other healthcare workers.
The 3-ply design functions to protect the wearer from inhaling small particles and stops respiratory droplets from accidentally falling or being projected onto other surfaces or people.
Surgical masks are non-woven and do not use fabric in their construction. Instead, the primary material in these masks is fibers made of synthetic materials such as polypropylene (PP).
The “3-ply” term refers to the three layers of material used to manufacture each mask: one layer of melt-blown, 25-gsm PP (grams per square meter) sandwiched between two layers of spun-bond of 20-gsm PP. This manufacturing technique creates what the industry refers to as SMS material: Spun-bond, melt-blown, spun-bond.
Protection levels of surgical masks
Although surgical masks may appear identical at first glance, they may not offer the same level of protection from one brand or manufacturer to the next.
The American Society for Testing and Materials (ASTM) defines testing protocols and standards for face mask effectiveness in ASTM F2100-11.
These standards test masks for fluid resistance (measured in millimeters of mercury, or mmHg), bacterial filtration efficiency (BFE), particle filtration efficiency (PFE, particles measuring ~0.1 microns), and differential of pressure (ΔP or Delta-P, measured in millimeters of water per square centimeter, or mm H₂O/cm²). In addition, all ASTM-rated masks must meet Class 1 flammability specifications.
Depending on their performance during testing, disposable face masks may fall into one of three protection levels:
- ASTM Level 1 – Low: Minimum fluid resistance of 80 mmHg, minimum BFE 95%, minimum PFE 95%, and ΔP of less than 4.0mm H₂O/cm².
- ASTM Level 2 – Moderate: Minimum fluid resistance of 120 mmHg, minimum BFE 98%, minimum PFE 98%, and ΔP of less than 5.0mm H₂O/cm².
- ASTM Level 3 – High: Same as Level 2, but with a minimum fluid resistance of 160 mmHg.
A face mask must meet all minimums for a given level to be rated at that level. For example, a face mask offering 99% filtration efficiency for bacteria and particles (exceeding Levels 2 and 3 standards) may still only be Level 1 if its fluid resistance is less than 120 mmHg.
When to use surgical masks
For non-healthcare personnel in most applications requiring a mask, any surgical mask offers adequate protection as long as it is ASTM-rated. The protection differences between level 2 and level 3 are minimal and are typically only relevant to specific healthcare contexts, such as surgeries.
However, non-ASTM-rated masks offer no guarantee they will provide you with sufficient protection against airborne diseases. While it’s possible they may still be sufficient (for example, if they were tested and rated under non-American standards, e.g., EN 149 in the European Union), it is more convenient to use masks with a clearly labeled ASTM rating.
ASTM-rated masks give you the peace of mind that your mask was tested and approved for use in the United States by all relevant organizations, such as the Centers for Disease Control and Prevention (CDC).
An N95 respirator (full designation: N95 filtering facepiece respirator), also known as an N95 mask, is an air-filtering and purifying device designed to protect the wearer from hazardous airborne substances.
Although the term “respirator” includes devices commonly known as gas masks, the N95 respirator is a mechanical filter respirator that only protects against airborne particulate matter and microorganisms. Unlike a gas mask, an N95 respirator will not protect against harmful gases or vapors.
Like multiple-layered surgical face masks, N95 respirators use synthetic non-woven materials in their construction, such as electrostatic melt-blown polypropylene. Some models may feature a plastic valve, allowing the wearer to exhale (to breathe out) more easily.
N95 respirators can provide a greater level of protection than surgical face masks. However, they require some degree of training to wear correctly, and they may not be suited for all individuals. An improperly fitted respirator may not protect the wearer to their advertised protection rating, and even tight-fitting masks can put additional strain on the wearer’s breathing.
Before issuing N95 masks to personnel, it is essential to conduct a medical evaluation to verify they can safely breathe while wearing an N95 respirator. After being medically cleared, each wearer should undergo a fit-testing procedure before each use to ensure the mask is sufficiently tight-fitting and provides an efficient seal.
N95 mask standards
Although not a specific model name, a mask qualifies as an N95 if it passes the standards and certification process outlined by the National Institute for Occupational Safety and Health (NIOSH) in 42 CFR 84.
Each letter and digit in “N95” refers to a specific standard, making it suitable for use in a given range of work environments.
- N: NIOSH air filtration rating, Class N. The NIOSH Class N rating is reserved for respirators designated “Not resistant to oil.” N95 masks do not protect the wearers against oil particulates, such as dioctyl phthalate (DOP).
- 95: NIOSH efficiency rating of 95% at 0.3 microns. This number indicates that the mask will stop at least 95% of all non-oil particles liquid and solid particulates with a diameter of 0.3 microns or greater.
In addition to being NIOSH certified, an N95 respirator may also be FDA-approved for use as a surgical mask. These masks may come with labels such as “Surgical,” “FDA Surgical Approved N95 masks,” and “Surgical N95 masks.”
FDA-approved surgical masks offer a slightly higher protection level than an ASTM Level 3 mask, as follows:
- Minimum fluid resistance: 160 mmHg (same as ASTM Level 3).
- Particle filtration efficiency: At least 95% at 0.075 microns, higher for larger particles.
- Bacterial filtration efficiency: At least 99%.
What is a KN95 mask?
Although the name is similar, the “KN95” designation should not be confused with “N95.”
The term “KN95” refers to a type of respirator that has passed GB2626-2006 certifications, which is a Chinese equivalent of the NIOSH N95. Although they are typically made in China and certified by the Chinese government, KN95 respirators offer protection roughly equivalent to N95 masks.
Do I need an N95 respirator?
N95 respirators, and especially FDA-approved surgical N95 masks, are recommended for use only by healthcare personnel in close contact with patients infected with (or suspected to have) airborne diseases. Even if you do not work in the public health sector, your employer may require you to wear one for work. Ensure you have passed a medical evaluation and a fit test before use.
A cloth mask is a generic term for a non-surgical face covering that was not tested or regulated for protection against particulate matter and airborne disease. Cloth masks are typically made of standard woven materials, such as cotton or polyester.
The CDC has conducted studies regarding the effectiveness of cloth masks, concluding that while any face covering is better than none, each type of fiber is different, offering varying levels of filtration and protection. The only certainty regarding the protection level of a cloth mask is that it is always inferior to a surgical mask or N95 respirator.
Cloth masks offer a distinctive advantage over disposable surgical masks: They are washable and reusable. They can serve as a complementary cover (double-masking in conjunction with a surgical mask underneath) or simply as an everyday face covering for legal compliance. Various accessories designed to improve your cloth mask’s fit are available, such as nose wires, mask fitting straps, or braces.
The CDC recommends against using face coverings that meet any one of the following disqualifying criteria:
- Masks that let respiratory droplets out (thus protecting the wearer but not others), such as cloth masks fitted with “respirator holes” or one-way valves.
- Face coverings not designed to be used as masks, such as scarves, bandanas, T-shirts, etc.
- Masks made of materials that excessively restrict breathing, such as vinyl.
- Face shields with large gaps on the sides and under the face do not stop the transmission of airborne diseases. However, wearing a face shield in conjunction with a surgical mask is efficient and may help protect your eyes.
Source Your Face Masks from a Trusted Manufacturer
Whether you need surgical face masks or N95 respirators, you want to be sure you can trust your supplier to get the highest level of protection available.
ICU Production, Inc. is a leading supplier of CDC- and FDA-approved personal protective equipment, including 3-ply surgical face masks, N95 and KN95 respirators, and many other products. Please browse our website or message us through our contact form for more information on our PPE product lines.