NEW YORK (AP) — The In-N-Out burger chain will bar employees in five states from wearing masks unless they have a doctor's note, according to internal company emails leaked on social media.

In the memo announcing new guidelines for Arizona, Colorado, Nevada, Texas and Utah workers, the fast food chain pointed to “the importance of customer service and the ability to show our Associates' smiles and other facial features while considering the health and well-being of all individuals.”

The policy, which goes into effect Aug. 14, applies to all In-N-Out employees in those states, except for those who need to wear masks or other protective gear for job duties that require it, like painting. Employees could face disciplinary action, including being fired, if they do not comply, the memo says.

California and Oregon both have laws in place preventing employers from banning masks.

It is not the first time that the chain, based in California, has clashed with health experts over safety measures that were first put into place as deaths from COVID-19 skyrocketed during the pandemic. In October 2021, several In-N-Out locations in California faced fines or were temporarily closed because the burger chain refused to enforce COVID-19 vaccination rules.

A company customer service representative confirmed the accuracy of the new mask guidelines with The Associated Press Wednesday. In-N-Out’s press contact did not immediately respond to requests for comment.

The new guidelines are facing pushback from public health officials like infectious disease specialist Dr. Judy Stone.

“Requiring a doctor’s note is also a burden in terms of time and money. Many people don’t have a primary care physician or one who is readily available," Stone wrote in a column for Forbes this week. “And requiring proof of a disability might be considered a violation of the Americans with Disability Act, depending on how one interprets masking as a request for accommodation.”

Stone also pointed to statistics from the Centers for Disease Control and Prevention — which notes that 6 in 10 adults have a chronic disease, increasing their risk for severe COVID-19.

In-N-Out workers in California and Oregon also have new mask guidelines set to go into effect Aug. 14, according to a separate leaked company memo. But in contrast to the other states, California and Oregon employees will still be able to choose to wear a mask in stores.

Those masks must be a company-provided N-95 mask, the memo says — adding that employees who wish to wear different masks must provide “a valid medical note."

Both memos note that policies are subject to local health regulations, and that the company will continue to evaluate accommodation for its guidelines.