Two people are being treated in hospital following an explosion at the Irish Oxygen plant on the outskirts of Cork city.
The roof and windows at the Cork plant at Waterfall were blown off when an acetylene gas cylinder exploded at around 11.20am.
Four people were working in the family-owned plant at the time.
The two who sustained injuries were taken to the decontamination unit at Cork University Hospital.
Their injuries are not said to be life threatening.
There were concerns initially that the plant's roof was made of asbestos and neighbours were warned to stay indoors as a precaution.
Emergency services personnel wore masks while they stabilised the situation at the plant.