An investigation is under way after a worker on the picket line at Greyhound Recycling in Dublin was injured.
The incident happened at around 10am yesterday morning at the depot on Knockmitten Lane in Clondalkin.
The man is being treated in hospital for injuries to his back.
Workers at the plant have been in dispute with management at the company since June.
Management are attempting to force workers to accept wage cuts of up to 35%.
Greyhound has said that workers will still be paid 10% above the industry average.