Immediately after the declaration of war in August 1914, emergency classes were organised in the college in various branches of military operations and also in first aid. By 1915 the college had two Voluntary Aid Detachment (VAD) Red Cross groups (one for men and one for women), who met hospital ships from the Western Front at Dublin’s North Wall and were active in giving aid to casualties of Easter Week 1916. The college building housed the central sphagnum moss collection depot for Ireland, organised and managed by the women’s VAD. This moss had been used for centuries as a safe and reliable dressing for wounds. As war casualties mounted, the demand for field dressings increased. By the time the centre closed in 1919 over 900,000 sphagnum moss dressings had been sent to hospitals in various theatres of war.
The RCScI laboratories were employed in research for the war effort, and staff were also involved in various wartime committees for food and fuel. The resources of the college were used for the testing and manufacture of fuse caps and adapters for use with high explosive shells, and airplane turnbuckles were manufactured for the air force. Others were employed in this work in addition to college staff. A significant number of voluntary workers came in at night and at weekends, including barristers, solicitors and court officials from the Four Courts Munitions Association.