N95 Respirators v/s Surgical face Mask – Effectiveness & Affordability

Today as we all live in unprecedented times of pandemic, it has now become more important than ever to comprehend what are the different types of safe breathing masks/respirators, their effectiveness, and at last, its affordability for the common man.

1. What is a homemade cotton mask?

Homemade masks can give some degree of barrier protection from respiratory droplets resulting from coughing or sneezing. Early reports show that the COVID-19 virus can live in droplets in the air for one to three hours after an infected individual has left an area. Covering your face will help prevent these droplets from getting into the air and infecting others. Homemade masks may protect others from you but offer little protection for you from others.

2. What are N95 respirators, and how do they work?

An N5 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles. Especially the edges of the respirator are intended to form a seal around the nose and mouth. The N95 mask filter medium contains a plastic made of polypropylene, and its fibre is similar to those used in our clothes like quick-dry shirts, rain jackets, yoga pants, or any stretchy fabric.

Besides the filter material, N95 masks can also include other materials, such as metal. The mask uses steel for the staples (which secure the straps to the mask) and aluminium for the bendable nose clip.

3. What is a Surgical Mask, and how do they work?

A surgical mask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. They are made of non-woven fabric, which has better bacteria filtration and air permeability while remaining less slippery than a woven cloth. Surgical mask are made up of a multi- layered structure different thicknesses and with different abilities to protect you from contact with liquids. These properties may also affect how easily you can breathe through the face mask and how well the surgical mask protects you.

Surgical masks, or sometimes called a medical cover, may also help reduce exposure of your saliva and respiratory secretions to others. A surgical mask on its own does not protect against “airborne” infectious agents, so it will not prevent the wearer from being potentially contaminated by a virus such as a coronavirus. However, according to experts, if everyone (infected people as well as healthy people) wears a surgical mask and respect hygiene and social distancing, it could be possible to reduce the transmission of the virus.  

4. When to use N95 Respirator, Surgical Mask, and homemade cotton mask?

N95 respirators should be certified by the National Institute of Occupational Health and Safety (NIOSH) to meet particular standards. They meet rigorous requirements for filtering efficiency of particles that are 100-300 nanometres in size. They protect the wearer from bacteria and viruses because they trap particulates in a complex of tangled fibres. N95 respirators should be reserved for frontline healthcare and other workers who need to use these masks as part of their job.

On the other hand, Surgical mask should be used by the common public when the infection rate and cases of coronavirus are high, which is currently the case in most of the countries. A surgical mask can also be recommended to healthcare professionals when N95 masks are not available. Surgical mask of good quality can provide >98 % bacteria filtration efficiency at 3.0 micron and > 98% particulate filtration efficiency 0.1-micron size.

The homemade cotton mask should be used in the low-risk situation and when there is no alternative available. In populated cities where maintaining social distancing is not possible at all the time, especially during visiting supermarkets, malls, salons, etc. or traveling by trains and buses, it is not recommended to use a homemade cotton mask. A cotton mask may be used in places or villages where there is the question of affordability or unavailability of a surgical mask and where the population itself is less.

5. When to discontinue using a mask and which is more affordable?

If your mask is damaged or soiled, or if breathing through the mask becomes difficult, you should remove the face mask, discard it safely, and replace it with a new one. To safely discard your mask, place it in a plastic bag, and put it in the trash. Wash your hands after handling the used mask.

Non-woven surgical masks are cheaper to make and cleaner thanks to their disposable nature, which are made with three or four layers.

 These disposable masks are often made with two filter layers effective at filtering out particles such as bacteria above 1 micron. The filtration level of a mask, however, depends on the fibre, the way it’s manufactured, the web’s structure, and the fibre’s cross-sectional shape. The middle layer of the surgical mask is made of melt-blown fabric that filters bacteria and viruses.

Another critical aspect of comparison is the price range. An N95 can cost from about 90 to 150 rupees per piece, while the surgical mask ranges from 10 to 16 rupees per piece. On a much practical approach, around ten surgical masks can be bought for a price for a single N95. For long term usage and affordability, it makes sense to use a surgical mask as it is economical and provides almost equivalent protection.

6. What is the degree of effectiveness of N95 respirators in comparison with a surgical face mask?

As per FDA regulation, surgical masks and surgical N95 respirators can be used differently based on their intended use.

N95 is made of 5 layers, while the surgical mask is made of 3 layers. Ideally, both of the masks are made of PP non-woven spun bond and melt-blown fabric, and additionally N95 may also have a cotton layer. The similarities between surgical masks and surgical N95s are:

• They are tested for fluid resistance, filtration efficiency (particulate filtration efficiency and bacterial filtration efficiency), flammability, and biocompatibility.

• They should not be shared or reused.

As per recent research, conflicting recommendations exist related to which facial protection should be used by healthcare workers to prevent transmission of acute respiratory infections, including pandemic influenza. A systematic review performed of both clinical and surrogate exposure data comparing N95 respirators and surgical masks for the prevention of transmissible acute respiratory infections indicated that there is no massive change in the degree of effectiveness. 

7. What is the ratio of use and reuse N95 mask in comparison with a surgical face mask?

Remember! Neither Surgical nor N95 should be reused. WHO and CDC both recommend that masks should not be reused as there are high chances of infection getting spread through reuse. Only in severe circumstances, a mask can be reused, and for that too, it requires passing through UV light, which cannot be found in any household. There are some other methods through which masks can be reused, but those are also very risky and tedious methods.

Wear a face mask & stay protected!!

References: 

·         JAMA. 2019;322(9):824-833. doi:10.1001/jama.2019.11645 & CMAJ 2016. DOI:10.1503/cmaj.150835