Face mask requirements: Can stores make you wear a mask? Do kids have to wear masks?

Businesses can require consumers to wear shirts, pants and shoes – but what about masks?

Conflicts at businesses and viral videos of shoppers' tirades have erupted in recent weeks as coronavirus cases surge in 40 states and at least 21 states pause reopening plans.

During the COVID-19 pandemic states have varied on mandates and some cities and counties issue their own requirements.

Last week, a woman without a mask at a California Trader Joe's called employees and shoppers "Democratic pigs" and screamed profanities because she said she felt threatened when a fellow customer cursed her out for not wearing a mask.

In Fort Worth, Texas, a woman was recorded spitting on a 7-Eleven counter Monday after the cashier refused to ring up her purchase because she was not wearing a mask.

Frontline workers, including grocery store employees, who fought for measures such as masks at the onset of the pandemic, are having to fight for the measures again, said Susan Hernandez, a longtime employee at a California Food 4 Less and UFCW 770 member.

“We urge shoppers to think of themselves, think of their families, and think of us when they are at the store. Please wear a mask," Hernandez said, noting when a customer “gets aggressive, we try to deescalate the situation.”

To protect workers, some retailers won't confront shoppers who enter without a mask.

"Walgreens encourages customers to wear face coverings but out of concern for employees’ safety, advises against confronting customers about the policy or trying to keep them from entering stores," the drugstore chain said in its COVID-19 frequently asked questions.

If you're planning to shop, know the answers to these FAQs:

Can stores and restaurants require masks?

Yes. Local governments can decide what safety measures to impose on businesses but individual businesses can institute further restrictions. Many governors are instituting or renewing orders requiring people to wear face coverings in public. Most of the orders require people to wear masks in both indoor and outdoor public spaces where social distancing isn't possible, but some apply to only specific places or age groups.

What stores require masks at all locations?

Stores requiring shoppers wear masks at all locations include Costco Wholesale Club and Apple. Other stores, such as Best Buy and Trader Joe's, strongly encourage masks.

Whole Foods and Wegmans are following local ordinances on mask requirements. Texas-based H-E-B started requiring all customers wear a face mask or covering when shopping in all its stores July 1, reported the Corpus Christi Caller Times, part of the USA TODAY Network.

Best Buy says on its website that "where face coverings are mandated by government order, customers will not be allowed into the store without one; small children and those unable to wear a face covering for health reasons may still enter.”

Do ride-shares require masks?

Yes. Both Uber and Lyft say drivers and passengers have to wear face masks. Uber has announced it was extending its mask requirement indefinitely throughout the U.S. and Canada.

“Extending our 'No Mask, No Ride' policy is the right thing to do," Uber said in a statement. "We want to send a clear message to everyone using Uber that we all have a role to play to keep each other safe.”

Are people wearing masks?

According to a recent Pew Research Center survey in June, 65% of U.S. adults say that they have personally worn a mask in stores or other businesses all or most of the time in the past month, while 15% say they did this some of the time. The survey also found 9% of adults said they hardly ever wear a mask and 7% said they never wore a mask in the past month.

Wearing a mask is a best practice widely agreed upon by scientists. Masks, even homemade or ear-loop masks, help slow the spread of the virus, according to studies. Yet while it is not a medical debate, it has become a politically charged one. According to a new report from nonprofit Media Matters for America, over the past month posts about masks from right-leaning Facebook pages earned more than 5.5 million interactions with the posts promoting skepticism about the efficacy of face coverings earning the most interactions.

What does the CDC say about face coverings?

The Centers for Disease Control and Prevention recommends that people wear cloth face coverings in public settings and when around people who don’t live in your household, especially when other social distancing measures are difficult to maintain.

"COVID-19 can be spread by people who do not have symptoms and do not know that they are infected," the CDC states on its website, where it also notes "wearing cloth face coverings may not be possible in every situation" or for some people and "may exacerbate a physical or mental health condition, lead to a medical emergency, or introduce significant safety concerns."

Can masks cause low oxygen levels?

The American Lung Association said in a June 18 blog that "masks are designed to be breathed through and there is no evidence that low oxygen levels occur" and that there is "absolutely no scientific evidence that mask wearing or physical distancing weakens the immune system." People with preexisting lung problems should "discuss mask wearing concerns with their health care providers," the association said.

USA TODAY previously fact checked claims on whether wearing a face mask for prolonged periods of time would cause someone to experience significant reductions in oxygen intake level, resulting in hypoxemia. The fact check found there was no evidence to support this as both cloth and surgical masks are unlikely to cause a dangerous drop in oxygen intake because they are not tight fitting.

"In general, if your breathing condition is well enough to allow yelling or being outside without oxygen, you can wear a mask medically," Dr. Jennifer Ashton, ABC News' chief medical correspondent, said when discussing the California Trader Joe's incident on Good Morning America June 29.

Face mask exempt cards? Not real.

While social media posts on "face mask exempt cards," claim the holder is exempt from wearing a mask due to health reasons, they are fake. The Americans with Disabilities Act website warns of "fraudulent facemask flyers."

An anti-mask group called the Freedom to Breathe Agency is believed to have created the face mask exempt cards, which according to images of the card posted on social media note "steep penalties" are threatened if a business owner does not act accordingly.

Are people with disabilities required to wear masks?

According to the Southeast ADA Center in Atlanta, which provides training and guidance on disability access, if “a person with a disability is not able to wear a face mask, state and local government agencies and private businesses must consider reasonable modifications to a face mask policy so that the person with the disability can participate in, or benefit from, the programs offered or goods and services that are provided.”

Reasonable modifications listed included allowing customers to order with curbside pickup, offering appointments and face shields instead of face masks, the center said in in a June 12 disability issues brief. However, businesses may not have to offer services if it is a fundamental change in the business model, it creates an undue burden or if a person poses a direct threat to the health of others.

“The requirement to modify a policy, practice, or procedure does not include individuals without disabilities, as they are not protected under the ADA.”

Should kids wear masks?

According to the CDC, cloth face coverings should not be worn by children younger than 2. Older children can and should wear masks, experts say. Schools across the nation are considering mask requirements when classes resumes. Like masks for adults, different areas have different requirements by age.

Wisconsin-based Menards, which in early April said it would no longer allow children under 16 to be in any of its stores due to the pandemic, is now allowing children again. "Children are welcome. Masks or face coverings are required on children unless in arms or seated in shopping carts," Menards said on its website.