Greyhound is appealing to workers protesting at their sites to stop blocking the entry and exit of other staff and vehicles.
Members of SIPTU, who work at the waste collection company, are striking over working conditions and wage cuts.
Greyhound says serious health and safety issues have arisen over the past two weeks at the gates of their depots.
The company is calling on the striking workers to abide by their High Court undertaking not to impede or obstruct people from going in or out of their premises.