Thread by @DrJwalaG

THREAD on Masks & Respirators

Which mask types are effective against Covid-19?

Face masks of different types have been in demand ever since the coronavirus outbreak became a global Pandemic

Lot of people have started wearing face masks
#CoronavirusPandemic #Covid_19 1/n

Apart from health workers, security officers and cashiers in supermarkets, regular commuters and blue-collar workers who take public transport have started wearing face masks in public. 

Some masks are effective for days, some are for hours.

MASKS 

Some FACTS regarding the different type of masks. 

1.What are the common types of masks

Cloth mask
Surgical mask

2. What are the Respirators

N- 95
N- 99
N- 100

3.Difference between mask & respirator

Mask has loose fit, it doesn't seal nose and mouth snugly.

During respiration air moves along the edges of the mask, while respirator has tight seal and most of the times air passes only through its material after filtration.

4.Are all respirator masks are same

No, respirators are graded according to their filtration efficiency.

According to the used filter type
According to the type of materials used 
And additional features
They are of different types.

5. what is the efficiency grading
According to the efficiency of filtration these are usually graded as-

95, 99 and 100

Means these respirator masks are capable of traping 95%, 99% and 99.9% of particles, smaller up to the 0.3 micron size.

This grading can also be done as
P1 (FFP1) - 80%
P2 (FFP2) - 95%
P3 (FFP3) - 99.95%
Face Filtering Piece (FFP) 
They are equivalent to N95 in Europe.

FF1 type is the lowest level mask for the protection. Generally, people who have respiratory diseases use FFP1 to avoid being affected by dust and similar substances. It can't keep the coronavirus at bay, however, as it is exclusively meant to be against toxin-free dust.

The medium level mask, FFP2, provides additional protection from chemically-laced air particles and dust. It's uncertain whether it can provide full protection from Covid-19.

When it comes to FFP3, It is the most effective mask against the coronavirus.

what is the N,R or P meaning written over mask
N - not oil proof
R- oil resistant
P- oil proof

(Example. N 95 is not oil proof).

Few respirator masks have valve, what is that?
That valve is nothing but a simple exhalation port with one way valve mechanism

it reduces effort of expiration, reduce heat inside the mask, dissipate humidity and reduce co2 the amount of from the  dead space of mask. (Dead space is a whole different topic that requires a Deep explanation ,I'm skipping )

When to use surgical masks.

Surgical mask or procedure mask is the most common mask used by health workers. 
It is not designed to protect wearer from inhaling the air born bacteria & viruses.
 It is used to block only large particle droplets, splashes, sprays or splatter

It also reduce the exposure of wearer's saliva and respiratory secretions to  others. Surgical mask also remind wearer not to touch their mouth/nose which could otherwise transfer virus/bacteria after having touched a contaminated surface.

what is the filtration capacity of surgical mask

It can vary between 10-90% according to the manufacturer.

how one can assure about the quality of mask

Mask should be certified by the
NIOSH (National institute for occupational safety and health)
Or

NPPTL (National personal protective technology laboratory)

Is cloth mask effective?
Cloth is a wooven material thus pore size is bigger than surgical mask which is made up of non wooven polypropylene material thus cloth mask is less effective than surgical mask in filtration

Does extra layer improve efficacy of cloth mask?

No, it's not advisable. Each extra layer adds only 2% of extra protection on the cost of comfort .

Can surgical/cloth mask be used routinely
Yes these can be used routinely.

Few studies done on normal population concluded that the use of simple mask can decrease the incidence of flu up to 75%.

Few east asian countries following this practice of routine use of mask

Can mask be reused?

Ans. -Cloth mask can be reused after washing

-Surgical mask should be discarded after single use or after soiled

-Respirator mask should be discarded when resistance of breathing get increased or get solied.

Viruses/bacterias can grow and flourish inside the reused mask.

What are recommendations for using masks?

We feel it is probably safe to wear one. In fact the US are advocating people should wear masks whilst in public. 

Sick person should wear the surgical mask to prevent spread.

Any person who is taking care of sick person should also wear the mask preferably the N95 mask. 

- N 95 mask should be used by health workers all the time as they have the potential to get exposed with the respiratory secretions of the infected patient

example - During the Endotracheal intubation, CPR, Ventilation, Bronchoscopy and Tracheostomy etc.
The N95 respirator reduces the wearer's exposure to tiny, invisible particles in the air, including bacterias and many viruses.

All FDA-cleared N95 respirators are labeled as "single-use," disposable devices. If your respirator is damaged or soiled, or if breathing becomes difficult, you should remove the respirator, discard it properly, and replace it with a new one

Facial hair and N95 masks: What you need to know

N95 masks require shaving beards to ensure a good fit.

abcnews.go.com/Health/beards-…

surgical mask, also known as a procedure mask, medical mask or simply as a face mask, is intended to be worn by health professionals during surgery and during nursing to catch the bacteria shed in liquid droplets and aerosols from the wearer's mouth and nose.

They are not designed to protect the wearer from inhaling airborne bacteria or virus particles and are less effective than respirators, such as N95 or FFP masks, which provide better protection due to their material, shape and tight seal.

CDC Recommends Cloth Face Coverings for Use by the General Public
N95 Respirators Not for Use by the General Public
The Centers for Disease Control and Prevention (CDC)

The design of the surgical masks depends on the mode; usually the masks are three-ply (three layers). The coloured side of the mask faces outwards, with the metallic strip uppermost. The strings or elastic bands are positioned properly to keep the mask firmly in place.

Here's pictures of different masks
N95 N99 N100 Respirators .
The 4th image is in detail .plz zoom in & read .
#COVID__19 #Masks #respirators

Difference between Face masks & N95 Respirators .

NIH study validates decontamination methods for re-use of N95 respirators

Three methods effectively sanitized masks for limited re-use.

nih.gov/news-events/ne…

This is a very good info showing you about the surgical masks & respirators thewirecutter.com/blog/face-mask…

This is the source of information .
trtworld.com/magazine/which…

There's lot more in detail about masks & respirators but for a layman this much info is enough .
I request all to read it once .
Reading is a good habit & especially in times of Pandemic such things you should be updated .
#coronavirus #Covid_19

Recommended Guidance for Extended Use and Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings

#Coronavirus #Covid_19
cdc.gov/niosh/topics/h…