Do Masks With Breathing Valves Prevent Coronavirus Spread? Doctors Say No

Face masks fitted with breathing valves do not provide adequate protection amid the coronavirus pandemic, experts said.

One-way valves fitted in certain masks provide more comfort to the wearers by allowing air to easily pass when they exhale. However, this function -- though convenient to users -- also allows the virus to spread if they happen to have an infection, doctors said.

Dr. Kai Singbartl, chair for infection prevention and control at Arizona's Mayo Clinic, said such masks defeat the purpose of containing the spread of the virus.

"They are unfiltered, those valves are the path of least resistance so to speak, it's easier to exhale and get rid of the heat and moisture," he said. Worst of all, viral particles and droplets can also go through the valves, he added.

Dr. Singbartl said they do not allow patients wearing valve masks inside the Mayo Clinic. If they wish to enter, they are asked to replace the face coverings with a different type of mask. He also admitted seeing some health care professionals who do not work at Mayo Clinic using masks with valves.

The same no-valve-mask policy is in place at the Camelback Dermatology and Skin Surgery clinic. "In a sterile field they're absolutely banned because it allows unfiltered, 'exhaled air in,'" Kristine Romine, one of the facility's doctors, told USA TODAY.

A spokesperson for Maricopa County in Arizona explained their face-covering mandate prohibits the use of masks with valves. The mandate declared valve masks do not comply with the mask requirements of the county. The order further stated the county's prohibition is based on guidance by the Centers for Disease Control and Prevention (CDC) which recommends against the use of masks with valves in healthcare settings.

In an email sent to members of the press by the Maricopa County spokesperson, she clarified Maricopa County Public Health is "not an enforcement agency." She further stated in the email that individuals and businesses should contact the non-emergency number of their local law enforcement agencies in case unresolved issues, such as those pertaining to masks, arise. The spokesperson recommended everyone should learn more about the masks.

Mask policies in other counties, however, do not include specific limitations against valve mask use. Other counties that prohibit valve masks do not always appear to enforce them, USA Today reported.

Dr. Singbartl also stressed everyone should use masks that cover the nose and mouth while researchers learn more about the bug. He said the wearers should make sure the masks fit snugly on their faces to stop virus particles or droplets from escaping or entering.

"In general, the more layers, the better," Dr. Singbartl said. Thread count is also an important factor as the higher the count, the more efficient their function will be as filters, he added.