They were protesting the board's support of legislation that would transfer about 22,000 university workers to a new UNC personnel system.
The news stirred up a heated debate among employees who are currently classified under the State Personnel Act.
Opponents said a consolidation could strip workers of various rights like severance pay, sick leave, and whistleblower protections.
UNC System officials said they need a personnel system that's tailored specifically to the higher education system to give them flexibility during tough times.
About 47,000 employees are currently managed by two different systems with differing rules and regulations.