Blue surgical masks are safe and recommended for the public to wear to help prevent the spread of COVID-19. Blue surgical face masks are made with non-woven fabric, which has been shown to have better bacteria filtration and airflow than woven cloth.

The material most commonly used to make these masks is polypropylene—a type of fabric made from a “thermoplastic” polymer (meaning that it’s easy to work with and shape at high temperatures). Blue surgical masks can also be made of polystyrene, polycarbonate, polyethylene, or polyester— all of which are types of fabrics derived from thermoplastic polymers.

It is not common practice for surgical masks to be manufactured using formaldehyde. However, some literature as well as reports from some surgical mask manufacturers have shown that blue surgical masks might include traces of formaldehyde and bronopol. These trace impurities of formaldehyde and bronopol have led to cases of contact dermatitis; however, these cases are not common, and have particularly been documented amongst individuals who are already susceptible to this condition either due to sensitive skin, allergies, or very long-term mask wearing (such as healthcare workers). 

Toluene—which is a toxic liquid used in gasoline—is not used to manufacture blue surgical masks and is not known to be found in surgical masks, even in trace amounts. On the contrary, toluene has been used to test how well different antimicrobial agents can filter out carbon and other pollutants when used on masks. 

Most surgical face masks also do not contain polytetrafluoroethylene (PTFE), the polymer that also makes Teflon, the brand name of a non-stick chemical coating commonly used on kitchen appliances such as pots and pans. If you do have a mask that contains PTFE, there is no evidence that wearing the mask would cause any flu-like symptoms or other negative outcomes when worn properly and normally. 

While some masks are sprayed with PTFE or have a PTFE filter, as PTFE has widely been used in the field of air filtration, it would take a mask with PTFE to 1) be heated to an extremely high temperature — 300 to 400 degrees celsius or 572 to 752 degrees Fahrenheit, 2) for fumes to be released, and 3) for those fumes to be breathed in, for any ailment to be caused.

To be completely sure of the safety of a surgical mask, it helps to know where it came from (that is, to be able to see and read the box). If you are concerned about any potential allergic reactions to surgical face masks, another great option is to purchase or create your own cloth mask, as long as it is made out of cotton or linen, has at least two layers of fabric, covers your nose, and mouth, and has ear loops.

Masks are a type of personal protective equipment (PPE), along with face shields, protective eye goggles, gloves, gowns, and other equipment. Proper use of PPE can help reduce the spread of COVID-19. Wearing PPE is a risk reduction measure, not a risk avoidance measure, so masks can help lower (but not completely eliminate) the chances of getting infected or infecting someone else. Maintaining hygiene, physical distancing, and other measures are still recommended.

There has been uncertainty around the safety of blue surgical masks and who should be wearing them. However, wearing surgical masks is safe and protective against COVID-19 when used properly.