Members of Dublin Fire Brigade fought a blaze at the pharmacy department of Trinity College Dublin yesterday evening.
There were fears that the fire would reach a solvent store on the roof of the three-storey building.
Five units of Dublin fire brigade went to the scene, which broke out on the third floor of the Smurfit Institute of Genetics. Firefighters wore the highest form of protection: chemical suits worn over breathing apparatuses, because of the risk from "unknown chemicals", according to the emergency services.
Although it took some time to locate the fire and set up a decontamination unit for the firefighters, the fire was put out in some 30 minutes.
It is believed that organic solvents such as ether and ethanol and other flammable chemicals typically found in university laboratories were on the premises.
The alarm was raised at 6.40 p.m. when the building's smoke alarm was activated.
Some 50 students and members of staff were evacuated.
There were no injuries.