The fire has been brought under control.
Eleven units of the Tipperary fire service have been fighting the blaze since 6.50pm yesterday.
Units from across North Tipperary are still at the scene of the major fire at TIPPO on the outskirts of Nenagh this morning.
Gardai say the alarm was raised at 6.50pm yesterday evening at the building in Nenagh.
Fire units from Thurles and Roscrea joined local crews from the town at the scene, while Gardai are also still attending.
The road, the R498 is closed from Ballinamona cross...Gardaí are at the scene and diversions are in place.
People that are travelling to Thurles from Nenagh are being advised to take the M7 to Roscrea and go via Templemore.
There are no reports of any injuries
TIPPO International Ltd is a supplier of PVC doors and windows, kitchens, and wardrobes for the Tipperary and wider Munster region.