surgical mask capabilities are much lower than most realize

Most people never think about wearing a mask until they suddenly discover that something they’re breathing is bothering them. Often times, the first thing that people will reach for is a surgical mask, because they are easy to find in any drugstore. Unfortunately, surgical masks capabilities are limited, and people often discover this the hard way.

There is a whole science of respiratory protection that most of the public knows little about. This science considers factors such as particle size, filtration ability, absorption, the ability of a filter to absorb certain gases, and adequate fitting to the face. But no layperson thinks about these things until they feel the need to protect themselves. In the best cases, people will realize that the a surgical mask is ineffective for their needs. In the worst case, people wearing surgical masks might expose themselves to toxins the mask can’t protect against, and make themselves sick in the process. This is another good time for me to reference this blog’s disclaimer about medical advice.

Surgical masks

Title: “Meeting Richmonders Abroad.” Photo originally posted on Flickr  by kitty meets goat under Creative Commons

The most common surgical mask seen in clinics and hospitals is the earloop surgical mask–named for how it’s secured to the face, not what it protects against. (Those toxic earloops!) This is basically the same one available at pharmacies. Medical staff will often wear them in hospitals. Clinics often insist that patients who are potentially contagious to wear them as well.

The main purpose of the mask is to keep contagious people from spreading their germs. That is what they are most effective for. They are less effective at protecting against other people’s germs, though the surgical mask is better than nothing. Frequently, the masks are pretty good at filtering out some types of dust. But those of us with allergies have often discovered that they are ineffective when it comes to our allergies.

One weakness of surgical masks is that they don’t often form an effective seal over the face. This seal is necessary to ensure that substances don’t find their ways around the edge of a mask. Inhaled and exhaled air tend to pass through the points of least resistance. Since a mask filter provides some resistance, some of that air will try to find a way around that resistance.

Surgical masks will often have gaps in three areas where air can easily pass through—along the sides of the mask by the cheeks, the area around the nose, and the area by the chin and jaw. Most surgical masks have a bendable piece of metal at the top to conform the mask to the nose. Even then enough air pressure can still easily push or pull air between the nose and the edge of the mask. You can see in the picture above that the wearers above didn’t conform the mask to their nose in this way, and that’s often true of many people new to wearing such masks. Gaps in the cheeks are often quite big, as is also noticeable in the picture above. If the masks are too big for the face, there can often be a large gap between the mask and the chin. These gaps can undermine the protective value of the mask.

Some surgical masks on the market are explicitly designed to protect against germs in addition to preventing their spread. Curad puts out a mask that has coatings that “inactivate” specific types of viruses and germs, and the box specifies which germs they will impact. The mask is a little thicker and its design is a little less likely to create gaps. In other cases, surgical respirators protect the wearer much more effectively by providing a tight seal and a more impermeable filter. Medical staff working around people with dangerous diseases or an immune suppressed person who absolutely must avoid germs might be seen with these masks.

For people with allergies and chemical sensitivities, there are a number of websites that offer a variety of masks to help control symptoms. Many of these are more effective than surgical masks. One such website,, even has a mask buying guide that is useful.

I certainly don’t mean to pick on the poor surgical mask.  It is good at doing what it’s designed to do–the problem is that most people don’t know what it is really designed for. If a surgical mask is the only mask available, and it’s not possible to get away to fresher air, it is sometimes better than no mask at all. But it is important not to have a false sense of security. An informed consumer needs to have accurate information about what mask works best under which conditions. Always read the product information on the mask’s packaging.  In any case, it is important to notice the smell and taste of the air you’re breathing—even if you have a mask on—and notice whether you are indeed avoiding what you need to avoid.