Masks are integral part of personal protective equipment (PPE) and during the season of Pandemic everyone is wearing it, it’s for sure. Masks like surgical mask , N-95 et c, we hear it on media to wear it to stop the spread of corona virus. But what does N in N-95 signify?
Has anyone wondered, well today we will talk about it , what are the types of masks?, what does first letter in the name mean ? what is the significance of number in the name.
But, First let’s talk about kinds of masks.
There are 3 kinds of masks based on their resistant property.
N TYPE OF MASKS
Here the N means NOT RESISTANT TO OIL , yes it is not resistant to oil, that clearly means, oil droplets can pass through it, if they are present in the environment.Now, what does number signify in the name. It means percentage of number of air born particles gets filtered through it.Example:- The 95 number in N-95 indicates 95% of air borne particles get filtered through it.
R TYPE OF MASK
These types of masks are resistant to oil. These types of masks are classified into R95, R99, R100. Here the numbers indicate 95%, 99%, 100% filtration efficiencies respectively.
P TYPE OF MASK
These types of masks are completely oil proof. These are also further classified into P 95, P 99, P 100. These types of masks are effective against air pollution, helps in protection against petroleum based contaminants (such as petrol, diesel), P M 2.5 particles, dust, cigarette, automotive smoke.
HEPA stands for High Efficiency Particulate Air Filter. It filters 99.97% of Airborne particles. These types of masks are used in Neurosurgery operation theatre, and other operation theatre.
BASIC STRUCTURE OF N-95 MASK
It’s outer layer is spun bound and is made up of Non- woven Polypropylene, which basically blocks droplets and water.It’s second and fourth layers are made up of Melt blown Non- woven fabric, which protects and holds the third layer between them.Now, it’s third layer is made up of PTFE (Poly tetra Flouro Ethylene).