After completing her master's degree, she stayed on at UCG as an assistant in the chemistry department for two years. In 1939, due to World War II, she changed paths to industrial chemistry and became chief chemist at the farm chemical manufacturer Hygeia Ltd in Galway. At Hygeia she was responsible for developing alternative sources for chemicals that were unavailable due to the war. During this time, she was also chief chemist at Cold Chon Ltd, a manufacturer of
bituminous binders and
road surfacing materials. Philbin was subsequently promoted to assistant lecturer in 1949 and college lecturer in 1955. She began to publish on flavonoid chemistry in earnest in 1952, working on the
Wessely-Moser rearrangement and
Baker–Venkataraman rearrangement in relation to flavonoid compounds. She earned her Ph.D. in 1956, then had a brief stint as a visiting fellow at the
Eidgenossische Polytechnikum Zurich with
Vladimir Prelog, working on flavonoid
stereochemistry. In 1958, she was awarded a doctorate of science (DSc) from the
National University of Ireland in recognition of her contributions. Philbin was one of the first women science professors at UCD when she became an
organic chemistry professor in 1962. In 1963, she took over as head of the chemistry department following the death of Wheeler, the previous department head. She continued to work on flavonoid stereochemistry and the compounds' role as potential anti-cancer agents through collaborations with researchers including Hugh Ryan and
Elias James Corey. She retired from teaching in 1979 from her professorship, but continued to conduct some research. Philbin became the first woman to chair the National Science Council, was the first female senior vice-president of the
Royal Irish Academy, and was the first woman president of the Institute of Chemistry in 1966. Since 2007, the
Institute of Chemistry of Ireland Annual Award for Chemistry lectures series has been named in her honor as the Eva Philbin Public Lecture Series. Philbin's interests ranged beyond science, taking a strong interest in the treatment of those with learning difficulties, leading her to take up the chair of the Consultative Council on Mental Handicap as well as becoming honorary treasurer of the National Association for the Mentally Handicapped of Ireland. == Personal life ==