Guidance from an Expert on Picking the Best Face Mask

As UMass prepares for the spring semester, environmental health scientist Richard Peltier offers some guidance on face masks, which are required to be worn inside all campus buildings.

Peltier, who conducted crucial research in his UMass Aerosol Lab at the start of the pandemic on the reusability of medical-grade N95 respirators by health care workers, explains in his Substack newsletter, Up in the Air, that masks function by filtering particles from the air. Masks filter droplets heading to the mask wearer and also emitted from the mask wearer’s nose and mouth. “The best ones work when there is a close, air-tight fit around the edges of the mask to your face. And this is the hardest part to achieve,” Peltier writes.

UMass is urging people on campus to use a certified, high-grade mask, such as an N95, KN95 or KN94 – or to double-mask with a close-fitting surgical mask and a cloth mask over it. 

Peltier explains that the codes of certified masks refer to standards of different countries. The U.S. certifies N95 masks only. Peltier points out that any certified high-grade mask, such as KN95 or KN94 – evaluated respectively by Chinese and Korean government standards – works well at filtering the smallest particles and providing a tight fit.

To avoid buying fraudulent “certified” masks, which are rampantly advertised, Peltier suggests reviewing tips from the CDC, Project 95 or the Mask Nerd. “And watch out for deceptive certifications – ‘M95’ looks an awful lot like ‘N95,’ but is not a mask that is certified by the government,” Peltier says.

In his newsletter, Peltier also lays out the strengths and weaknesses of different types of masks, and how to best choose which type of mask to use in different situations.

“Public health is about protecting yourself and those around you. Consistent mask wearing and widespread vaccinations offer us the best chances to reduce our risk of contracting COVID-19 – both on campus, and off,” he adds.

With the continuing increase in Omicron infections across the U.S. and globe, it is more important than ever to remain vigilant. Masking is a relatively easy way to reduce exposures to infectious droplets and particles that might transmit COVID, Peltier notes.

“Public health is not a zero-sum competition; no one loses when we take preventive measures,” Peltier says. “But everyone can lose if we don’t.”