The rapid spread of the omicron variant means that are urging Americans to adopt better masking protocols to protect themselves and others from the spread of Covid-19. Masking best practices have changed since the beginning of the pandemic, and confusion still abounds about which mask to wear and in what circumstances. However, medical experts are in agreement: Masks are a crucial component in stopping the spread of all variants of Covid-19, and the National Institute for Occupational Safety and Health (NIOSH)-approved .

Although a simple is better than no face covering at all, are now widely available — much more so than in March 2020, when Centers for Disease Control and Prevention guidance about whether masking was even necessary for Covid-19 prevention vacillated.

And since the appears to , masking is a critical tool in helping prevent the spread, particularly in areas where Covid-19 cases are high. Here’s what to know about masking and omicron.

How mask usage should change with omicron

Mask-wearing guidance has changed a lot over the course of the pandemic, and omicron presents more changes — as well as more opportunity for confusion. With the high transmissibility of the omicron variant, experts say, masking is particularly important. Omicron is estimated to be about among inoculated people than the , which rapidly became the world’s dominant strain last summer. While many people are experiencing milder cases with omicron, , even in highly vaccinated areas. Its ability to dodge antibodies created by the available Covid-19 vaccines means that additional prevention measures — like masks — are now back in the spotlight. As Abraar Karan, an infectious diseases doctor at Stanford University, explained to in December, cloth masks and face coverings don’t filter aerosols — the particles through which the coronavirus spreads — particularly well; they can escape from an infected person and easily be inhaled if both parties are wearing cloth face coverings. That means surgical masks and N95 masks are the way to go in 2022, as a illustrates. N95 respirators in particular are much better at blocking these particles, , due to the filter’s structure and the electrostatic charge that attracts and traps the tiny aerosol particles. Just as critically, the filter’s fit over the wearer’s mouth and nose is far better than a cloth mask or face covering, which can leave large gaps on the sides — giving infectious particles ample opportunity to escape.

How can you get the right mask?

The N95 has been the gold standard for masks since the start of the pandemic, and they provide the most protection against Covid-19, including the omicron variant. Now that they’re no longer in critically short supply, they’re also the best option for day-to-day use.

, the N95’s complex, irregular webbing allows for superior filtration which traps 95 percent of aerosol particles — hence the “95” in N95. KN95s similarly filter out 95 percent of particles; the K denotes that they are . When used in a medical setting, N95s are generally single-use, but for average people in lower-risk settings, they can be a limited number of times. N95 availability was scattershot at best in the beginning of the pandemic, even for health care workers. Now, nearly two years later, are much more readily available. Cost is still a potential barrier, however, as N95s generally cost a , and counterfeit respirators pose an additional problem, as Anne Miller, executive director of the nonprofit Project N95, explained to in December. Nonetheless, Miller said, there are some failsafe ways to ensure that the model you are purchasing was manufactured by a reputable company and has passed NIOSH filtration tests. Specifically, N95 masks should have a TC number; TC, followed by a series of five total numbers, then a lot number. KN95 respirators operate under a similar protocol; all models should have GB 2626-2019, followed by a space, then KN95, printed on them if they are produced by a reputable company. According to Miller, lack of a brand name on a mask or a claim on the mask’s packaging that it’s FDA-approved or registered with the FDA are major warning signs; those claims are essentially meaningless. However, high-quality respirators that have been tested for fit and efficacy , and doing a few basic tests on masks yourself can help you weed out ineffective models. For one, , you shouldn’t be able to see light through the mask when you hold it up to a light source, nor should you be able to blow out a flame when wearing the mask. And in terms of fit, the sides should collapse when you breathe in, showing that your mask has an effective seal. If air escapes around the sides of the mask, you need a tighter fit, since aerosols can still flow in or out of the barrier. If you can’t find an N95 or KN95, a surgical mask is quite effective as well, given its multiple layers and irregular weave, which is better at intercepting particles than the regular, uniform weave of cloth masks. Surgical masks aren’t quite as effective as N95 respirators, but they use the same filtration mechanism. Fit is also crucial, since surgical masks don’t have the same structure as N95 masks and don’t mold as well to the nose and mouth area. However, fit can be improved by or twisting the side loops before placing them over your ears for a closer fit. Despite still-existing barriers like cost and confusing messaging, it’s easier now in 2022 to buy an effective N95 or KN95 respirator that’s comfortable and fits your face. And in combination with Covid-19 vaccines and boosters, which provide , a good quality, well-fitting mask is one of the best steps you can take to protect yourself as case numbers .