Covering the nose and mouth has been used traditionally to
prevent contraction of contagious diseases in a sanitary matter of sense.
However, the use of face masks as we know now is a more modern approach.

As per history, face masks were first invented to prevent
the dangers of human exhalation as causes of surgical wound sepsis. These masks
were made mostly from gauze. Their effectivity was increased by increasing the
layers of gauze. Later on, face masks were then provided to patients to prevent
them from spreading their illness, such as, infantile paralysis and also to
protect their caregivers. At this point masks sterilization after single use
and the avoidance of using bare hands on masks was promoted.

These gauze medical masks were
replaced by disposable ones which were made from synthetic material in the
1930s. In the 1960s, new kinds of disposable filtering masks made using
non-woven synthetic fibers started getting used. The introduction of disposable
masks came in to promote the ‘total disposable system’ of syringes, trays,
needles and even surgical instruments. This was as an effort to not compromise sterility.

In 1975, it was somehow concluded
that reusable masks, made using muslin and four-ply cotton was better than
disposable paper masks and synthetic respirators. Some studies have even
suggested that washing reusable masks may tighten their fibers even increasing
their filtering efficiency.

As is evident from this brief
history, face masks have been here awhile and they have adapted to different
ranges hence the range of face masks kindly available and their different

Currently, the range of face masks
available include:

1.       Respirators
such as:


N95/FFP3/FFP2 respirators.


2.       Surgical

3.       DIY/Homemade

Note the difference:



Most masks as we know them do not
necessarily protect the wearer but the people he comes across. Hence the
respirators. This rating also refers to particulate matter or pollution
particles in the air.


N95 is the most common respirator
this is partly managed by the CDC under an American standard managed by the
National Institute for Occupational Safety and Health (NIOSH). In Europe, they
use the “filtering face piece” (FFP) score under the EN standard 149:2001.

What’s the difference in these

As is evident, the N100, N99 and
FFP3 and P3 offer the best protection at 99.97%, 99%, and 99.95% respectively.
In comparison, the N95 is equivalent to the FFP2/P2 at 95% and 94%



The Chinese KN95 is equivalent to
the N95.

However, since KN95 are held in
place by ear loops unlike the N95held on the back of the head by a headband.
The result might be a weaker seal by the KN95.

Due to counterfeits and regulation
challenges, most KN95 might not meet the required Chinese standards.

Its specification is known as the
GB 2626-2006 or the updated GB 2626-2019, which is written on the respirator.


These percentage standards only
specify the minimum percentage of particles the respirator filters. For
example, the N95, it is 95% of particles that are 0.3 microns, which is the
most penetrating particle size (MPPS) or larger in diameter.

Some respirators also differentiate
with the aspect of having a valve or not. Respirators with valves allow for
easier exhaling. Because of this, they are more comfortable and have less
moisture build-up inside the respirator. However, they do not filter the
wearer’s exhalation. Hence it is risky for people around the wearer. Hence it
is not recommended for hospital use. It is more appropriate for construction
and DIYs. Putting a surgical mask on top of the Valve having respirator in a
hospital situation is thus recommended.


In addition, we also have surgical
and non-surgical respirators. These range in the afore mentioned respiratory
category while also being fluid resistance. These are mostly used in surgery.

N95 Respirator 3M Model 8210

Surgical N95 Respirator 3M Model 1860

Surgical N95 Respirator 3M Model 1870+

Designed to help protect the wearer from exposure to airborne
particles (e.g. Dust, mist, fumes, fibers, and bioaerosols, such viruses and




Designed to fit tightly to the face and create a seal between the
user’s face and the respirator




Meets NIOSH 42 CFR 84 N95 requirements for a minimum 95% filtration
efficiency against solid and liquid aerosols that do not contain oil




Cleared for sale by the U.S. FDA as a surgical mask




Fluid Resistant – Meets ASTM Test Method F1862 “Resistance of Medical
Face Masks to Penetration by Synthetic Blood” which determines the mask’s
resistance to synthetic blood directed at it under varying high pressures [1]

                                           120 mm Hg

                                          160 mm Hg

to the 
3M website

The ASTFM F1862 is a standard testing method testing the
resistance of medical facemasks to penetration by synthetic blood

The procedure for this test
specifies that a mask or respirator is conditioned in a high-humidity
environment stimulating human use.


1.       Not
fitting or not wearing it well.

2.       Always
touching the front which catches viruses.

3.       Unnecessary
exposure risks due to the false confidence it gives.

How to put on a respirator:



These are three-layer designs
(3-ply) having two sheets of non-woven fabric sandwiching a melt-blown layer in
the middle that provides the filtering capability.


Surgical mask passes the
standardized methods ASTM F2100 EN 14683 or any equivalent. This helps avoid
low quality products.

The test looks like the table


Normally, surgical masks are
primarily for protecting vulnerable patients from medical professionals. They
also don’t have a tight seal like respirators. However, standard surgical masks
have a stiff bendable edge on the top side to create a faux-seal.

That said, they are still a good
option than having nothing.

to put on a face mask

Clean your hands with soap and water or hand
sanitizer before touching the mask.

Remove a mask from the box and make sure there
are no obvious tears or holes in either side of the mask.

Determine which side of the mask is the top. The
side of the mask that has a stiff bendable edge is the top and is meant to mold
to the shape of your nose.

Determine which side of the mask is the front.
The colored side of the mask is usually the front and should face away from
you, while the white side touches your face.

Follow the instructions below for the type of mask you are using.

Face Mask with Ear loops:

Hold the mask by the ear loops. Place a loop around each ear.

Face Mask with Ties:

Bring the mask to your nose level and place the ties over the crown of
your head and secure with a bow.

Face Mask with Bands:

Hold the mask in your hand with the nosepiece or top of the mask at
fingertips, allowing the headbands to hang freely below hands.  Bring the mask to your nose level and pull
the top strap over your head so that it rests over the crown of your head.  Pull the bottom strap over your head so that
it rests at the nape of your neck.

Mold or pinch the stiff edge to the
shape of your nose.

If using a face mask with ties:

 Then take the bottom ties, one
in each hand, and secure with a bow at the nape of your neck.

Pull the bottom of the mask over your mouth and chin.

to remove a face mask

Clean your hands with soap and water or hand
sanitizer before touching the mask. Avoid touching the front of the mask. The
front of the mask is contaminated. Only touch the ear loops/ties/band. Follow
the instructions below for the type of mask you are using.

Face Mask with Ear loops:

Hold both of the ear loops and gently lift and remove the mask.

Face Mask with Ties:

Untie the bottom bow first then untie the top bow and pull the mask
away from you as the ties are loosened.

Face Mask with Bands:

Lift the bottom strap over your head first then pull the top strap over
your head.

Throw the mask in the trash. Clean your hands with soap and water or
hand sanitizer.


These are currently endorsed in order to spare the surgical masks and
respirators for healthcare practitioners.

The table below shows the effectiveness of various household items as
face masks:

REF: Cambridge University Study.

Items such as pillowcases and cotton
t-shirts are good materials for homemade face masks. They have a good filter
efficacy and breathability. They can also be sown or modified. They do not
protect against much of viral or bacterial particles but are good in limiting
the spread of aerosols and droplets to contain infection spread.









Face masks are an integral part as protective equipment that reduce both
transmission and contraction of droplets, aerosol transmitted infectious
agents. If used properly, they stop us from touching our nose and mouth
limiting contraction.

DIY/ Homemade masks and single use masks which are mostly one layered
are mostly effective against dust particles but are not as useless either way.

Surgical masks can trap up to 0.1-micron particles.

While respirators capture great than 90% of virus sized particles.

It is also key to note that mask standards vary by region and required

All in all, masks are necessary but it is important that the right mask
is used for the right purpose.

Compiled by:

Powell Omolo