Amidst the sudden increased use of masks and respirators, it is often easy to lose track of what is being used as what. This can be an issue as not all masks can be termed as respirators. For example, a common misconception that has mystified this difference between masks and respirators is the use of surgical masks.
What are surgical masks used for?
Surgical masks were designed to be used by medical professionals and not for regular public use. But these masks were still readily available over the counter along with other medical equipment. Recently the increased demand for masks and respirators, especially N95 respirators has led to increased production of all types of the mask due to the current pandemic situation at hand. A surgical mask is designed especially to stop the transfer of water droplets from the facial region such as mouth and nose. This is effective to a certain point in controlling the transfer of germs and infection from a medical professional to a patient, especially during surgery. This was the previous intended use of surgical masks was before the pandemic crisis.
Do they differ?
At this given situation, it is necessary to understand how a surgical mask works to know what the difference is between a surgical mask and a respirator. Most surgical masks come with a fluid repellent layer which is to be worn outward. The other layer, the absorbent one, is supposed to be worn inward. This would be effective in stopping the transfer of water droplets. But the question is if this is enough to stop bacteria and viruses from travelling. The answer would be a simple no. This mask is not designed to stop particulate matter like viruses and bacteria from travelling inside humans. The sole purpose of this mask is not built around the fact that it stops bacteria and viruses from travelling but instead just the water droplets.
Types of surgical masks
There are various types of surgical masks and not all of them are manufactured to be worn during surgery. There are four most common types, dental, medical procedure, surgical and isolation masks. But none of these act as respirators. Besides droplets and aerosols, surgical masks can protect against large respiratory particles. There is leakage around the edge of the mask which makes it inefficient in preventing the entrance of small particulate matters.
The working mechanism of surgical mask and respirators
Respiratory filters that can collect 95% particulate matter are assigned with the number 95, as seen in an N95 respirator. Those respirators which can collect 99.7% particulate matter are given a rating of 100. N, R and P designation is allotted to respirators which are capable of protection against oil-based aerosols.
Comparison of filtration efficiency
There have been multiple studies to find the difference of filtration that can be carried out by surgical masks and respirators. It has been observed that the filtration rate in surgical masks can widely vary depending on the type of surgical mask and its quality which further depends on the manufacturer. It has been observed that the efficiency of collecting particulate matter in surgical masks can vary from 90% to 10%. This is a very wide range of variation which is why its use in the pandemic for protection against the virus has been questioned again and again.
Filtration of respirators
Respirators are required to have a higher standard of collection and filtration than surgical masks; it is only after that they receive their certification as a respirator. The fit of a respirator is also equally important to prevent the entry of germs to a higher percentage. This offers a lot more protection as surgical masks are prone to leakage at the edge. Respirators are expected to not only have a higher standard of filtration rate but also a tight fit edge. Respirators vary depending on the coverage area of the face which is also deemed as equally important. It is hence not only for the higher filtration and collection rate that respirators are more suitable for preventing entry of bacteria, viruses and other particulate matter but also the area of coverage and the good quality fit of the equipment.
Working principle of respirators
Respirators work in two different ways, positive pressure and negative pressure. The positive pressure respirator creates positive pressure inside the respirator. This is done by pushing clean air through a compressor within the respirator. In comparison, a negative pressure respirator works by having the wearer breathe in air through the chemical cartridge or the filter into the mask or facepiece. There is still a chance of inward leakage in a negative respirator which is why a positive respirator offers more protection than a negative respirator.
The fit on surgical masks and respirators
As mentioned earlier the fit is a big deal for differentiating efficacy of surgical masks and respirators and to differentiate among the two. Firstly the surgical mask has multiple entry points of germs but may fit better and is more easily breathable according to many. This makes the work of a respirator quite challenging. The respirators are hence manufactured to have a tight yet subtle fit on the chin and mouthpart otherwise it couldn’t be qualified as a good quality respirator. It is hence necessary for a respirator to avoid being too tight on the face yet has the mouth, chin and nose part covered to the best possible effect. This is the basic difference between a surgical mask and a respirator besides the difference in the quality of filtration. The quality of filtration is what has proved respirators to be more effective in providing protection in a pandemic than a surgical mask.