N95 respirators are forms of face-covering respirators used by individuals to cover their faces to protect against some kind of toxic airborne particles that, if breathing enters the human body, can be detrimental to human health. Several public health organizations that work to test medical products to ensure the safety of human beings have approved N95 masks.
N95 masks are manufactured or made up of different protective layers that make the feature more powerful. The N95 mask is made of non-woven synthetic fiber that can philter approximately 95 percent of the harmful particles in the air.
The use of polypropylene became more and more popular in a number of consumer and industrial applications and it was gradually discovered that this type of plastic showed potential as a textile as well.
Polypropylene fabric is a textile that is nonwoven, which means that it is made directly from a material without the need for weaving to spin.
This attribute enables moisture to evaporate much more quickly when wearing a polypropylene garment than it would with a moisture-retaining garment.
Considerations of CDC about Masks:
The CDC suggests that people wear masks in public spaces, such as public and mass transit, at festivals and meetings, and wherever other people are around them.
Masks can help avoid the spread of the virus to others by individuals who have COVID-19.
When they are commonly used by individuals in public environments, masks are most likely to minimize the spread of COVID-19.
Masks should NOT be worn by children under the age of 2 or someone who is unconscious, incapacitated, or otherwise unable to remove the mask without help if they have difficulty breathing.
To help prevent the person wearing the mask from transmitting COVID-19 to others (source control), masks with exhalation valves or vents should NOT be worn.
Polypropylene is effective because it can hold a static charge that repels particles. While a N95 mask is made to hold that charge for the life of the mask, by ironing the polypropylene or rubbing it with a plastic glove for 20 seconds, you can generate a charge with a homemade filter.
What’s so special about polypropylene?
" The material used in masks made from N95 is the same," Chu says. The N95 mask is used by medical professionals and filters up to 95% of the particles that are airborne. But Chu cautions that there are differences between store-bought polypropylene and the type used in medical-grade N95 that consumers need to be aware of.
" The quality of N95 polypropylene is calibrated and designed for a standard specific level of filtration," she says. Two layers of Spun bond polypropylene can approach, although not duplicate, the protective qualities of a single layer of medical quality mask filters. Two layers of Spun bond polypropylene can approach, but not duplicate.
Polypropylene makes N95 masks most effective:
Polypropylene is effective because that can hold a particle-repelling static charge. While a N95 mask is made to hold that charge for the life of the mask, by ironing the polypropylene or rubbing it with a plastic glove for 20 seconds, you can generate a charge with a homemade filter. The Chu says the charge will last for approximately 12 hours or until it's washed.
There's an alternative that virtually anyone can use if polypropylene isn't available. Simply stuff four sheets of Kleenex into the mask pocket (or two sheets folded in half). The Kleenex gives you good particulate blocking and breathability efficiency, "Chu says."
Obviously, when they're available, medical professionals choose an N95. But what is the Chu doing when it's time for a cloth mask to be worn? "I'm wearing a mask made locally," says the Chu. " These are two polypropylene layers pocketed by cotton in the front and back”
A breathable mask with a safe filter, coupled with social distancing and hand washing, can slow the spread of the virus, reducing infectious droplets that come from the mouth of a person. The Chu says, " That's why masks are perfect." " We know that's exactly what works."
Can non-woven polypropylene be harmful to breathe?
In both N95 and medical masks, non-woven polypropylene is used. It's not supposed to shed fibers, says James Scott, a professor and head of the division of occupational and environmental health at the University of Toronto's Della Lana School of Public Health.
Even if it did shed, he estimates that "higher than I would ever expect from a shedding mask" is the allowable exposure to such fibers.
He added that when they are cleaned between uses with gentle hydrogen peroxide without damaging the filter material, N95 masks can be reused up to 10 times. He does not know, though, how durable non-woven polypropylene is at home after repeated laundering.
Meanwhile, in our homes, so many other things are made of synthetic materials that you probably already breathe in plenty of polypropylene fibers in the dust around you anyway. A 2016 study by French researchers found that 33% of the fibers found in indoor air were synthetic and that the predominant material was polypropylene.
For masks, filtering layers of non-woven polypropylene are recommended:
Dr. Theresa Tam, Canada's Chief Public Health Officer, updated the recommendations for non-medical masks in early November. Instead of two, she now recommends that the masks be at least three layers and that the third layer be a filter-type fabric, such as a polypropylene non-woven fabric. She said, however, that you don't need to throw your two-layer masks out.