Given all of the potentially confusing or contradictory information about Personal Protective Equipment (PPE), the difference between a mask and a respirator is a fairly common question. Typically, all N95 devices are technically respirators, however there is a difference between the N95 respirator and the surgical N95 respirator. While they may all appear to be “masks” in some shape or form, they are not essentially the same thing. However, if given the designation of N95, it is considered to be a respirator.
In this article we will go over the differences between masks and respirators. A mask (in most cases) will typically refer to a “surgical” mask; these look different and have a different purpose than do respirators.
The easiest way to understand the difference is to recognize that a surgical mask is designed to protect others from infection or exposure to airborne particles, including various liquids and bodily fluids. Respirators will also protect others from these elements but are also designed to protect the wearer from inhaling small particles.
The “95” in the N95 designation refers specifically to the percentage of particles that the respirator is designed and tested to protect from and against. In other words, an N95 respirator should protect the wearer from approximately 95% of all airborne particles.
The factor that defines a surgical respirator is that it is designed to filter both inhaling and exhaling activity. All air movement, including any particles that may be in the air will be forced to go through the outer fabric; the device is designed to fit close against the face of the wearer.
Masks, on the other hand, tend to be looser fitting, and much can be breathed through openings on the side. They do not force respiration to occur through the fabric of the mask. As a result, they are more comfortable to wear (breathing is easier) but they are less effective at filtering out various materials.
Differences between surgical masks and N95 respirators
First of all, let us look at how they are similar. Both use a fabric that is created by a melting/blowing process.
However, the real differences lie in three areas:
- Attachment Method
- Fluid resistance (as determined by different testing agencies)
Any mask which provides any form of fluid resistance, must be approved in the U.S. by the Food and Drug Administration (FDA). Those that do not provide fluid resistance (such as those manufactured out of cloth fabric) are considered to be masks but are not considered to be Personal Protective Equipment (PPE). For all FDA approved masks, they must be tested by the American Society of Testing and Materials (ASTM). These are rated on five different measurements.
ASTM Level 1 face masks should be able to filter at least 95% of .1-micron particles, as well as a wide range of bacteria. There should be some level of fluid resistance to these masks, such as blood at the pressure of 80 mmHg. For higher levels of masks, particularly ASTM levels 2 and 3, these must meet several requirements such as flame resistance, and still make it possible for a wearer to breathe comfortably through them. Typically, these masks will include a range of filtering layers to protect against airborne particles. These masks will also often have a metal nose clip to help provide a seal with the face of the user, but they are not considered to be airtight. Because of this, they are not generally considered to be adequate protection from airborne vapors or viruses.
There are a few basic facts that we need to understand about what constitutes a mask that is not considered to be a respirator. They may have labels which designate them as medical, surgical, or dental masks. They are designed to be used to protect against exhalation, and not inhalation – they are designed to protect patients and not those wearing these devices.
They may serve to protect the wearer at a minimal level against exposure to bodily fluids or large air particles, but because of their lack of tight fit, they are not considered to be ideal as PPE devices.
They fit loosely over the mouth and nose of the wearer and are not sized for individual users. They are approved by the FDA, but not NIOSH (The National Institute for Occupational Safety and Health).
We need to reiterate that surgical masks are not designed to fit closely over the face. As we have mentioned previously, they are designed to help prevent the spread of exhaled particles, and people within the vicinity from being exposed by contaminants that a wearer may (knowingly, or otherwise) be carrying. There are some tighter fitting surgical masks, however these will still have some gaps between the mask and the face of the wear, so they are not designed to fully protect wearers.
Respirators of this type are regulated by a separate agency. As they are designed more for safety of the wearer than those around the wearer, they are managed by the National Institute for Occupational Safety and Health (NIOSH).
The N95 mask must have a filtration capability of at least 95% of 0.3-micron particles (non-oil based). To be designated an N95 respirator, it must have elastic straps which will hold the mask tightly against the face of the wearer and must be fitted to individual users. It is worth noting that the particle size with which these devices are tested are larger than that which is used for surgical masks.
0.3 microns is what NIOSH considers to be the size of the type of aerosol which is most likely to penetrate and are considered to be the worst-case scenarios faced by mask wearers. The reason for this size of particle is because N95 filters do not use a net-like function for capturing particles, but instead capture them using diffusion. In other words, these masks are constructed with a maze-like pattern of fibers which makes use of normal random airflow to cause contaminants to be trapped within the fibers. This is considered sufficient for capturing particles which (within the .3-micron size limit) are difficult to trap.
The basic features of an N95 respirator are as follows:
- They are designed to reduce exposure to most airborne particles. They are not sufficient to completely eliminate the risk of exposure and will not work on oil-based aerosols.
- They designed fit securely over the mouth and nose of the wearer
- They follow the Occupational Safety and Health Administration (OSHA) standard known as 29CFR 1910.134
- For N95 respirators without exhalation valves, they may help prevent some contamination by the wearer to others in their immediate environment
- They are NIOSH certified
- They are not considered to be fluid resistant.
Surgical N95 Respirators
Surgical N95 respirators are a subset of N95 respirators, which have also been approved by the FDA under the guidelines of surgical masks, and also provide some resistance against fluids.
The Surgical N95 respirator has the following features:
- They are designed to reduce exposure to most airborne particles but are insufficient at eliminating all risk of the wearer being exposed to airborne contaminants. They serve to reduce risk but are not guaranteed to protect against illness.
- Like the standard N95 respirator, it is designed to create a tight seal over the nose and mouth of the wearer.
- They follow the same OSHA guidelines as regular N95 respirators (29CFR 1910.134)
- There are a set of requirements and warnings that come with them when being used in medical or healthcare environments.
- They are certified by NIOSH
- They do provide some levels of fluid resistance and are measured using a liquid with a similar viscosity as blood.
The difference between N95 Respirators and Surgical N95 Respirators
Now that we’ve covered some of the high-level regulatory information, let’s compare the following three types of PPE side by side: N95 Respirators, Surgical N95 Respirators, and Surgical Masks.
Surgical masks are approved by the FDA, and N95 respirators are approved by NIOSH. However, it is important to understand that NIOSH and FDA both approve Surgical N95 respirators, which are considered to be a subset of N95 Respirators.
The primary difference between the N95 Respirator and the N95 Surgical Respirator is associated with its ability to handle any sort of fluid resistance. In other words, the regular N95 is suitable for construction environments (or any place where the wearer might be exposed to fine particulates) but does not necessarily handle saliva, blood, or other liquid substance.
There are many functions that healthcare workers perform which provide a good deal less risk than others, such as the likelihood of exposure to or generation of high-pressure liquid streams. These functions are generally not considered to be surgical procedures. In these cases, the N95 respirator may considered to be sufficient for the adequate protection of healthcare workers, and will protect against the most common forms of normal contamination, such as those caused by coughing or sneezing of a patient
Let us look at the functions and uses of each:
- N95 Respirator – Reduces particles inhaled by the worker
- N95 Surgical Respirator – reduces particles both inhaled and exhaled by the wearer
- Surgical Mask – reduces particles exhaled by the wearer
- N95 Respirator – used primarily for respiratory protection when a wearer is exposed to particles
- N95 Surgical Respirator – used during surgery where both the wearer might be exposed to airborne particles, as well as particles which might be exhaled or expelled which might contaminate a patient, or if any resistance to fluid is required.
- Surgical Mask – used during surgeries or other tasks designed to protect patients from further contamination
Length of Wear
While there is likely to be some variation in policies between different institutions and facilities, the following is a set of guidelines regarding the length a person should wear a protective device.
- Surgical Masks – these should generally be discarded after each use; they are typically only worn for specific procedures where a patient may be exposed to potential bacteria or viruses.
- Surgical N95 and industrial N95 respirators – these may be donned and removed in an area that is external to any area that is contaminated. They should never be removed when within a contaminated area, and this can immediately put the wearer at risk of exposure to hazards. This will, of course, vary depending on the nature and circumstance of wearing of these materials.
Difference between N95 and KN95 Masks
When searching for PPE online, one may see both N95 and KN95 respirators available for sale.
While both may have the same protective qualities, they are approved according to different standards. The N95 is approved by US regulatory agencies (NIOSH, and FDA for the N95 Surgical Mask), and the KN95 is approved by Chinese regulatory agencies.
Both of these masks are made using polypropylene and plastic polymer layers and are created to be fit tightly over the nose and mouth of the wearer. In both cases there are usually straps behind the ears or head of the wearer to help keep it in place. Approval in both cases requires that 95 percent of materials larger than 0.0 microns be filtered and captured.
The two masks are quite similar in pretty much every aspect, and the two regulatory agencies have almost identical guidelines for what is a sufficient mask (though there have been some reports of non-compliant KN95 masks from some factories in China, in many cases these masks are just as good, if not better than the N95). It is important to note that just because a mask is designated as N95 does not mean that it was manufactured in the U.S. Many N95 masks are manufactured in other countries as well; the designation refers specifically to the regulatory agency which approves them.