A controlled explosion of school lab supplies has taken place in Dublin's St Stephen's Green.
It's after Nitric Acid became unsafe at a nearby school.
Gardaí and the Army bomb disposal team were called to the scene at 5am.
The acid is found in school science departments around the country.
It deteriorates over time and becomes unsafe if it crystallizes.
The army says it carries out about 10 controlled explosions on the substances each year.
It says this morning's operation was routine and there are no safety concerns for pupils.
