As movie theaters come back to life across the country, the National Association of Theater Owners is helping to take the guess work out of safe operating practices in the era of COVID-19.

The trade organization is announcing a set of health and safety protocols Friday based on research and guidelines from the Centers for Disease Control and Prevention, the World Health Organization and the Occupational Safety and Heath Administration. Over 300 companies representing more than 2,600 theater locations in the U.S. have already signed on to the CinemaSafe program.

"In this new pandemic world, moviegoers need to know that there is a consistent, science and experience-based set of health and safety protocols in place no matter what theater they visit," said John Fithian, the association's president and CEO, in a statement. "This unprecedented industry-wide effort is a promise designed to meet that need."

The guidelines outline comprehensive mask policies, which are required for employees and patrons with a few exceptions for children under 2 years old and when consuming concessions — but only when approved by state and local health authorities. The rules state that masks should also be provided to employees who don't have them.

They also sketch out recommendations for reduced capacity screenings, air filtration optimization, cashless concessions, mobile ticketing, enhanced cleaning policies and employee health training about hand hygiene and the signs and symptoms of COVID-19.

The association has been working for months to develop the rules in consultation with epidemiologists and industry experts. The organization's executive board includes the leaders of the major exhibition chains, like AMC Entertainment, Cinemark and Cineworld/Regal.

Most indoor movie theaters shuttered in mid-March to help prevent the spread of coronavirus. This week, the major theater chains in the U.S. have started to slowly reopen locations. Although many have said they are complying with local mandates and generally accepted best practices, there was not until now a set of industry-wide guidelines. This lack of oversight led to situations like the mask backlash that resulted in all the major exhibitors reversing course to require face coverings.

The CinemaSafe protocols are voluntary. Companies complying with the guidelines can display a CinemaSafe badge on their websites and, eventually, at their locations so patrons are aware.

Dr. David F. Goldsmith, an occupational and environmental epidemiologist at George Washington University's Milken Institute School of Public Health, reviewed the CinemaSafe guidelines.

"These protocols, and the way they were developed, demonstrate a serious, comprehensive effort by movie theater owners to examine every aspect of their operations, identify potential risks, and reduce them," Goldsmith said.

Dr. Joyce Sanchez, an infectious disease specialist and director of the Travel Health Clinic at Froedtert & the Medical College of Wisconsin, said that the protocols address, "Two of the three general concepts that factor into activity risk: distance, dose and duration."

Sanchez said that duration can't be controlled but noted that movie runtimes are similar to that of a domestic flight or time spent at a restaurant.

"While every activity outside the home carries risks, these additional measures can help to mitigate them," she added.