A chemical leak at the Poolbeg Incinerator in Dublin needs to be fully investigated, according to Sinn Féin.
It saw 11 workers hospitalised after lime was accidentally released during testing on Wednesday.
The management company say the leak was contained and the plant is safe.
Sinn Féin's Environment spokesman Brian Stanley says Dubliners need reassurance that the facility is safe.
"I think the best way is not to create waste in the first place but to be honest we're stuck with this giant white element but at the very least what we need here is an EPA investigation and the Health and Safety Authority to carry out thorough investigations into what happened here, and indeed inspect the plant with a view to ensuring that it's safe as we move out into the future," he said.