ARMY BOMB DISPOSAL experts have made safe an unstable chemical after sealing off several streets near St Stephen’s Green in Dublin.

The military unit was called in to the Catholic University School on Lower Leeson Street, after a quantity of picric acid was found. The bomb disposal team removed the chemical to a nearby piece of open ground, then carried out a controlled explosion.

Traffic was stopped in the area as the unit arrived at 4.15pm. The scene was declared safe at 6.10pm.

According to the Defence Forces, the substance was discovered during a routine audit of chemicals held in the school’s science department. Picric acid is a reagent which is routinely used in laboratories, but over time it can crystallise and become unstable.

It has caused a number of alerts in recent weeks, including some at schools in Limerick and Celbridge, and the offices of the pharmaceutical regulator in Dublin. The Leeson Street incident is the 21st time this year that the unit has dealt with dangerous substances, and its 186th call-out since January.