This comes after workers at the Johannesburg RAF offices were allegedly exposed to harmful working conditions.
In September a fire in the CBD resulted in extended power cuts, which meant the air conditioning units were not working at the RAF building.
The union said eight workers fainted from the heat, caused by working in a windowless environment.
"The building has poor sanitation exposing workers to potentially dangerous illnesses and infections,” said Numsa.
The union on Tuesday said it has lodged a grievance with the Commission for Conciliation, Mediation and Arbitration (CCMA).
"We felt that the management at RAF in
"They did not care that workers were suffering and did nothing to ensure that working conditions are safe.”
Numsa also said the management of the RAF continues to be in shambles.
The union said workers at the Menlyn branch have been forced to share workstations because the computers in the Litigation and Determination Department were seized by the sheriff.
Although the CCMA has granted Numsa the right to strike over this issue, the union said it wants to avoid a strike and settle the dispute amicably.
This would entail suspending the employee relations manager and general manager.
- BUSINESS REPORT ONLINE