Halloween parties at work can be fun, but they can also expose your company to legal liability if not properly planned, says Chicago employment lawyer Michael Karpeles.

Karpeles suggests having employees participate in planning the Halloween celebration, to accommodate as many concerns and viewpoints as possible.

"For example, companies should show sensitivity to those employees who would be offended by the event because of religious or other beliefs," he says. "These employees should have the opportunity to opt out of the celebration."

Set ground rules in advance

"The company should clearly set the ground rules for the party, including proper behavior and appropriate costumes," Karpeles advises.

"You don't want an employee coming dressed as a commando carrying a toy assault rifle in this age of workplace violence. These kinds of costumes can be unsettling to other employees, and the company could hear about it later in the form of a lawsuit."

Halloween celebrations are different than other celebrations, says Karpeles: "When people put on a costume, they sometimes think they can get away with behavior that they wouldn''t consider otherwise."

"This is one office party where the company has to be vigilant in ensuring proper behavior," he says. "Remind employees in advance through friendly memos and e-mails of what is expected as far as behavior and dress. Review your company's policies for events and make sure the Halloween party you are planning is consistent with those policies."

Karpeles is a principal in the Chicago law firm of Goldberg, Kohn, Bell, Black, Rosenbloom & Moritz.