LAS VEGAS >> The union representing thousands of housekeepers in Las Vegas today said Caesars Entertainment has rejected a proposal to include language in a new contract that would protect workers if a “Do Not Disturb” sign has been hanging on a doorknob for more than 24 hours.

The Culinary Union said under its proposal, security would open a room before a housekeeper enters if a guest has refused housekeeping for more than 24 hours. The proposal comes as the hospitality industry adopts new room checking policies after a gunman in October broke windows in his Las Vegas Strip hotel suite and carried out the deadliest mass shooting in modern U.S. history.

“If a guest refuses entry to housekeeping employees for more than 24 hours the Employer’s security shall open the guest’s room for entry and service by housekeeping employees and shall remain in or next to the room as long as the Security Department deems it necessary to protect the safety of housekeeping employees,” the union said, wanting to include the words in the new contract.

The organization is currently negotiating contracts for thousands of members who work in Las Vegas, including those working at casino-resorts operated by Caesars Entertainment. The contracts of 50,000 union members, including housekeepers, cooks, bartenders and food and cocktail servers, expire at midnight May 31.

The company, one of the world’s largest casino operators, did not immediately return a request for comment. Caesars Palace, Flamingo and Paris are among the properties it operates in Las Vegas.

In February, it told The Associated Press that security would begin checking rooms every 24 hours, even if the sign is hanging on the doorknob. The company proposed having housekeepers do the checks, but changed its mind after opposition from a casino workers’ union.

Other gambling and hospitality companies have adopted similar policies requiring guest rooms to be checked periodically, even if a “Do Not Disturb” sign is in use, including Disney, Hilton, MGM Resorts International, Wynn Resorts and Boyd Gaming. The frequency of checks ranges from 12 hours to two days.

MGM, the owner of the Mandalay Bay casino-resort from which a high-stakes gambler killed 58 people and injured hundreds more, said it requires a room check after two days if a guest has not interacted in person or over the phone with housekeeping or other hotel staff. MGM said it also “reserves the right to enter the room if it is deemed appropriate to conduct a welfare check.”

Two Caesars employees represented by the union in a news release said they don’t feel safe when entering a room that has had the sign on for extended periods. Amalia Urciel, who works at Bally’s, said rooms that have had the sign for days make her “shaky.”

“I am constantly going into a room that staff hasn’t been in for four days and never know what I’m going to find when I open a door: It could be completely trashed room or a dangerous situation,” Urciel said in a written statement.