 |
| An excerpt from “Simple Respiratory Mask”, page 1033 |
With
the current concerns over the COVID-19 and shortages of masks, and with the
sincere hope that you never need this information, I am writing this article. I am not an alarmist, I haven’t bugged-out for the woods...yet, laugh
out loud! I like to read about prepping
though, my
Father says that I would stop to read soup labels and he’s probably right. I am also not a doctor and I don’t even play
one on TV. I just read a lot and I found
this article several years ago and thought that I would pass it on to you.
I
am not saying that you need to stockpile N95 masks or make homemade, simple
respirator masks because of the coronavirus, however “forewarned
is forearmed”1 and it never hurts to know how to do things. A simple homemade respiratory mask,
equivalent to a N95 mask, made with locally available materials, which can be
washed and sterilized with methods available worldwide, “...may be a
solution if commercial masks are not available”2.
However,
before I begin I need to share the opinions and disclaimers of the CDC with
regards to this article, since it was published on their web site: “The
conclusions, findings, and opinions expressed by authors contributing to this
journal do not necessarily reflect the official position of the U.S. Department
of Health and Human Services, the Public Health Service, the Centers for
Disease Control and Prevention, or the authors' affiliated institutions. Use of
trade names is for identification only and does not imply endorsement by any of
the groups named above”3.
So, draw your own conclusions from the material below, I am not offering
medical advice and I do not represent, endorse, guaranty or warranty this
information: it is simply provided for your continuing education and
enlightenment.
 |
| Photograph by the author. |
There
are two types of face masks, and the air purifying respirator masks like the N95
masks offer more protection than a simple disposable medical face mask or a
surgical mask, both of which are generally loose fitting.
Disposable
face masks simply create a barrier between your nose and mouth and splashes or large
particles and droplets. They cannot
filter out the very small particles or droplets that are created when people
talk, sneeze or cough. They also do not
fit tightly around your face and therefore, they allow air to leak under the
mask and into your mouth and nose. This
type of mask, by definition, is disposable and if they become damaged, dirty, soiled
or stained they should be disposed of and replaced with a new mask.
The
U.S. Department of Labor recommends air purifying respiratory masks, either
N95, N99 or N100 masks for workers working with victims of viruses. Remember viruses like the corona virus,
COVID-19, spread when infected people sneeze, cough or talk, spewing droplets
containing the virus into the air and possibly into the eyes, mouth, nose,
throat or lungs of a nearby person. The
greater the N-value of a mask, the greater the protection a properly fitted
mask provides: N95 respiratory masks are 95% efficient at filtering the 0.3µ (micron)
particles created when people talk, sneeze or cough. Another thing to know about N95 masks is that
they can be fatiguing to wear, the authors of a “Simple Respiratory Mask”,
noted that while the testers wore this mask for an hour without any difficulty,
they could not comment on what it was like to wear while performing strenuous
work or in adverse environments.
 |
| Photograph by the author. |
To
make this simple respiratory mask you will need a heavy-weight T-shirt. The authors of this study used a Hanes
Heavyweight 100% cotton T-shirt made in Honduras, I used a Gildan Ultra Cotton,
100% pre-shrunk T-shirt, made in Nicaragua.
You will also need a pair of sharp scissors and a ruler or tape-measure,
and a magic marker doesn’t hurt.
Before
beginning, boil the T-shirt for ten minutes and then air dried it, this
maximizes shrinkage and sterilizes the cloth: this method of sterilization is
available worldwide.
 |
| An excerpt from “Simple Respiratory Mask”, page 1033 |
Step
One: The Outer Layer
To
make the outer layer, you need a piece of T-shirt that is 14-½ inches tall to
just over 28 inches long (37 cm tall by 72 cm long). I found that if I cut upwards to the bottom
of the sleeve and then around the back of the T-shirt to the bottom of the
other sleeve and then another 5 inches (about 13 cm) further around towards the
front of the shirt, I would end up with a piece of cloth with the correct
dimensions.
 |
| Photographs by the author. |
Step
Two: The Inner Layers
In
this step you will make the eight inner layers for the simple respiratory mask
from pieces of T-shirt that are 7 inches tall by 7
inches long (18 cm tall by 18 cm long). I
found that I was able to cut out three of the inner layers from the material on
the back of the shirt between the sleeves.
The other five pieces came from the front of the shirt.
If
you have a wide face, the authors of this study, suggested that you make and
use inner layers that are larger than 7 inches square (18 cm by 18 cm square),
so that you will have less air leakage when you wear the mask.
 |
| Photographs by the author. |
Step
Three: Making the Ties
This
step is the easiest. First, I assembled
the inner layers; two layers cross-grain, two layers straight, or lengthwise-grain,
two layers cross-grain, and finally two more layers laid straight-grain.4 I placed the assembled inner layers onto the
bottom center of the outer layer.
 |
| Photographs by the author. |
Next,
I measured down 5-½ inches (14 cm) from the top edge of the outer layer and
then made a 9 inch (23 cm) long cut in towards the center of the outer layer, I
did this on both sides This creates tie
“A” which is then rolled down, in a roll that is about 1-¼ to 1-½ inches wide
(32 to 38 mm), stopping at the top edge of the inner layers. Measure up from the bottom edge of the outer
layer by 6 inches (15 cm) and then cut in toward the center on both sides, making
a cut 9 inches (23 cm) long; and these two cuts create ties “B” and “C”
 |
| Photograph by the author. |
Step
Four: Making the Nose Slit
 |
| An excerpt from “Simple Respiratory Mask”, page 1033 |
 |
| Photographs by the author. |
Make
a “nose slit” for the bridge of your nose in the center of tie “A”. Measure in from either edge about 14 inches
(36 cm) and make a slit about a ¼ inch (64 mm) from the top and bottom edge of
the 1-¼ to 1-½ inches wide roll that is tie “A”. This slit should be 1 inch long (25mm) and
penetrate through no more than three layers of tie “A”.
 |
| An excerpt from “Simple Respiratory Mask”, page 1033 |
Now
that the mask is made it is time to put it on.
I found that it is easier to put the mask on in front of a mirror. Start by putting the “nose slit” in tie “A”
over the bridge of your nose and then tie, tie “A” below the back of your
neck. Adjust the fit around your nose
and cheekbones to eliminate any air leakage.
If the seal is not tight and there is air leakage, the authors of a “Simple
Respiratory Mask” suggest that you push the rolled fabric of tie “A”, up or
down on your cheekbones until the leakage stops. If the seal is still not tight the authors further
suggest that you push extra T-shirt material under tie “A”, between your cheekbones
and your nose. I cut out an extra 7 inch
by 7 inch (18 cm by 18 cm) piece of T-shirt to use as an air leakage cloth.
 |
| Photograph by the author. |
Next
tie, tie “B” over and on top of your head.
If the ties are too short, knot extensions to each end of tie “B”. I cut out extensions which were 3 inches wide
by 9 inches long (8 cm wide by 23 cm long) from the remains of my T-shirt. These are about the same dimensions as tie
“B” and should give you plenty of length to knot this tie over your head.
And
the last step in putting on this mask, is to tie, tie “C” behind your head and
voila, you are masked.
 |
| Note the roll of cloth, just visible on the bridge of my nose, tucked under my mask to stop air leakage |
 |
| Photographs by the author. |
The
authors of a “Simple Respiratory Mask” noted that commercially available N95
respirators required a fit factor of 100 against aerosol contaminants to be
considered adequate in the workplace.
The homemade mask featured in the “Simple Respiratory Mask” study,
achieved with one author, a fit factor of 67 and a fit factor of 13 and 17,
with the other two authors, who had larger faces. The authors felt that this homemade N95
respiratory mask would have a lower fit factor and therefore be less effective
than commercially manufactured N95 respiratory masks. They felt that this would be especially true
when these homemade masks were made by amateurs. Additionally, they thought there might be
problems due to variations in locally available materials, cultural practices,
facial structures, beards, etc. It
should be noted that when using any respirator, you need to be clean-shaven...sorry
guys! The authors of this study did not
recommend using this homemade mask in place of a commercially manufactured N95
mask, however they did feel that this homemade mask provided a good fit and a
measurable level of protection from aerosol contaminants. In the end it comes down to “something is
better than nothing”.
I
hope that you continue to enjoy The Woodsman’s Journal Online and look for me
on YouTube at Bandanaman Productions for other related videos, HERE.
Don’t forget to follow me on both The
Woodsman’s Journal Online, HERE,
and subscribe to BandanaMan Productions on YouTube. If you have questions, as always, feel free
to leave a comment on either site. I
announce new articles on Facebook at Eric Reynolds, on Instagram at
bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.
That
is all for now, and as always, until next time, Happy Trails!
Notes
1
“Forewarned is forearmed” means that you can be appropriately prepared
if you know something in advance. Knowledge
in advance enables one to be prepared in advance. This expression originated as
a Latin proverb, Praemonitus, praemunitus, which was translated into
English by the early 1500s as “forewarned, forearmed”, and it has a
similar meaning to the saying “a word to the wise”. From the Free Dictionary by Farlex, https://idioms.thefreedictionary.com/forewarned+is+forearmed
and The Phrase Finder , https://www.phrases.org.uk/meanings/forewarned-is-forearmed.html
2 Virginia M. Dato, David
Hostler and Michael E. Hahn, “Simple Respiratory Mask”, page 1033
3 CDC,
Center for Disease Control and Prevention, Emerging Infectious Diseases
4
According to the web site, The Spruce Crafts, “What Is a
Fabric's Crosswise Grain?”, cross grain is “The crosswise grain of a
piece of fabric is a term that describes the threads that run perpendicular to
the length of fabric as it comes off the bolt”, this grain runs across the
width of the cloth. Therefore, straight
or lengthwise grain of a fabric is the term that describes the threads that run
parallel to the length of the fabric as it comes off the bolt.
Sources
CDC, Center for Disease Control and
Prevention, Emerging Infectious
Diseases, June 2006, Volume 12,
Number 6, https://wwwnc.cdc.gov/eid/article/12/6/05-1468-f1, accessed March 5, 2020
Dato, Virginia M.,
Hostler, David, and Hahn, Michael E. “Simple Respiratory Mask”, Emerging
Infectious Diseases, June 2006, Volume 12, Number 6, p. 1033-1034. https://dx.doi.org/10.3201/eid1206.051468, accessed March 5, 2020
Kekatos,
Mary; “Mask mania”, February 27, 2020, Dailymail.com, https://www.dailymail.co.uk/health/article-8051799/Can-face-mask-really-protect-against-coronavirus.html,
accessed March 5, 2020
Wickell,
Janet; The Spruce Crafts, “What Is a Fabric's Crosswise Grain?”, https://www.thesprucecrafts.com/what-is-a-fabrics-crosswise-grain-2821571,
accessed March 10, 2020
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