To this day we have all become experts (or almost experts) on a topic that is always on everyone's lips, masks. They are already part of our daily lives and we use them mainly to protect others & prevent the spread of germs.
Today we will explain the different types of masks that we can find and, in particular, we will talk about valve masks.
Hygienic Masks: Designed to protect from the inside out by preventing the transmission of infectious agents. They are "solidarity masks" because if everyone wears them, it prevents the spread of the virus. They can be reusable or non-reusable.
Reusable ones, such as Ubik, can be made of polyester/cotton, 100% cotton or polyamide. To be certified, they must offer bacterial protection greater than 90% and breathability below 60 PA/cm2. These masks can be washed at a temperature between 60 degrees and 90 degrees.
Surgical Masks: Like hygienic ones, they protect from the inside out and also partially from the outside inward. Generally speaking, they should not be worn longer than four hours. There cant be reused.
N95 Masks - are a type of respirator and protect more than a surgical mask because, when inhaling, they can filter large and small particles. They are designed to block 95% of particles of very small size. Some have valves that make it easier to breathe through them.
Self-filtering masks: also known as PPE (Personal Protective Equipment) (PPE) with European CE marking. Its use is intended primarily for professionals and vulnerable groups by medical indication. They aim to filter the inhaled air avoiding the entry of polluting particles into our body.
The latter have different filtering capabilities. Therefore, and according to the protection index, we can divide into three groups the high efficiency FFP masks (and in the case of FFP2 and FFP3 we can also find them with valve):
- FFP1: have a 78% minimum filtration efficiency and 22% outward leakage.
- FFP2: filter around 92% & 8% outward leakage.
- FFP3: filter around 98% & 2% outward leakage.
This type of masks can be reusable and not reusable. And we can differentiate them by the presence of the letters “R” or “NR” respectively.
How do valve masks work?
Valved masks are those that have this element to improve the ergonomics of those who wear them because it prevents moisture and heat accumulating inside the respiratory protector.
The valve has an internal membrane to allow outside air to enter when inhaling, thus protecting us from possible external viruses and bacteria. But on exhalation, the membrane moves outwards leaving an opening that releases CO2 and moisture from the inside, getting the temperature down.
In this way, the masks that use a valve prevent moisture and heat from forming inside the mask by releasing hot air from our body and thus avoiding sweats and irritations on the skin.
Why is it not recommended to use masks with exhalatory valve
Both masks that have exhalation valve, and those that do not, protect the user. And with regard to bacterial filtration effectiveness (EFB), the presence or absence of valve in this type of mask is not relevant. Because with an effectiveness of 92%, the outward filtration is identical.
However, the percentage of virus spread outward varies considerably.
In face masks without valve it is 8% but in face masks the ejected air is not filtered, so the virus can spread equally.
The valve masks only protect from the outside in. That is, the wearer could not be infected, but could be infect others. The valve filters only the inhaled air, and the infected exhaled drops are not filtered and pass outside. Another added problem is that the person wearing this type of mask, on exhalation, concentrates the air at a specific point. So, someone close to us can be infected.
Who can use valve masks and in what situations?
The goal of including a valve that closes when inspired and opens when exhaled is to make them more comfortable for the worker who uses them. Because, by allowing air to flow out, the valve helps to regulate the temperature by preventing condensation and moistening the fabric.
These one-way valves are designed to be used for long periods of time and can help us not to inhale smoke from a fire or sawdust from a woodworking shop, because they protect us from these elements. In this way, they are useful for construction workers or people who are working in a workshop or in a dusty place.
On the other hand, they can be used by health workers to create a barrier with potential infected people. However, hospital staff cannot use them in environments where air needs to be sterile because they do not filter out the exhaled air.
Finally, they can also be used by vulnerable population groups having been recommended for use by doctor's prescription in advance.
But in no case can infected people wear valve masks because they do not protect the people around them.
What are the best masks for the general population?
For the general population and infected people, surgical (single-use) and hygienic masks, such as Ubik, are recommended, which can be reused if they are UNE 065 or 064
In the case of health care, caregivers and population at risk, FFP2 and FFP3 are considered to be the most suitable, recommending the use of FFP2 in activities with low or moderate risk, leaving FFP3 to high-risk circumstances.
However, in no case is it recommended that valve masks be used by the general population, because they only protect the person wearing it and not the others.
We hope that this article was useful to you.