Gov. Ned Lamont’s recent announcement of a possible $100 fine for not wearing a mask has re-ignited the debate over face coverings, with some wondering whether they actually offer protection against COVID-19.

But health experts are fairly united in believing that face coverings, with a few notable exceptions, are essential to stopping the spread.

“Masks — along with physical distancing, self-isolation if you feel sick, and proper hand-washing — is one of the most effective measures we currently have to limit the spread of COVID-19 and allow us to move past the pandemic,” said Michael Urban, director of occupational therapy at the University of New Haven. “The fines proposed by Gov. Lamont only reinforce the need for us to change our behaviors and wear a properly fitted face mask.”

Michael Parry, chief of infectious disease at Stamford Hospital, echoed those thoughts. He said masks are more effective at preventing an infected person from spreading the illness to others, than they are at protecting someone from breathing in the virus.

“But the combination is what you want,” he said. “You want the infected person to wear the mask and the uninfected person to wear a mask, so you can have additive protection.”

However, not all masks are equal. A Duke University study, published Sept. 2 in the journal Science Advances, compared 14 different kinds of masks, based on their ability to filter out the droplets expelled from a person’s mouth when speaking.

Participants were asked to say the phrase “Stay healthy, people,” five times — first while wearing no mask, then while wearing each of the masks in the study. They were recorded and a computer algorithm was used to count the particles in each video.

The researchers found that a fitted N95 mask did the best job of keeping droplets from spreading. N95 masks have long been touted as the most effective. A three-layer surgical mask was deemed next most effective at containing droplets, with multiple variations of fabric masks were ranked below these.

A gaiter-style neck fleece did the worst job of containing droplets, with double-layered bandanas and knitted masks rounding out the bottom three.

Urban also advised against wearing a plastic face shield without a mask underneath. But, in general, he and other experts said some sort of face protection is better than none.

“Face coverings of nearly every kind help reduce aerosols when speaking or interacting with others,” said Summer McGee, associate professor of public management at the University of New Haven. “In short, face coverings work and successfully can mitigate COVID-19 spread”