Pupils and staff were evacuated from a school amid fears that acid in a science lab had become potentially explosive.
Gardai were alerted by authorities at Colaiste Lorcain in Castledermot, Co Kildare when picric acid in the lab was discovered to have crystallised.
An Army bomb disposal team arrived at the school shortly after midday yesterday and removed the acid to a safe location where it was destroyed in a controlled explosion.
Picric acid is commonly used in science labs in schools and colleges and in commercial laboratories as a substance to help chemical reactions. The acid is normally safe in liquid form but if it is found to have crystallised, it can explode.
The school was declared safe at 3pm.
A Defence Forces spokesman told the Herald that Army experts had been called out "at least five times" last year and this year to deal with the problem of picric acid crystallisation.
Unusually, Army ordnance experts were also called to the regional veterinary laboratory in Kilkenny yesterday morning to deal with another picric acid find. This was also dealt with by a controlled explosion and the area was declared safe after 35 minutes.
The bomb disposal teams are trained to deal with chemical compounds in addition to weapons, explosives and munitions.
Last November, army bomb experts were called in to deal with a quantity of unstable picric at a Teagasc facility.
Gardai called in the Army to deal with the acid at the Teagasc site in Oak Park, Carlow town. The bomb disposal team later destroyed the acid in a controlled explosion.