[2] During the Second World War, Ennor was engaged by Australian Chemical Warfare Research in top secret trials in northern Queensland of mustard gas protective clothing and other counter-measures.

He and fellow-biochemist J. W. Legge designed and oversaw the construction of a 100 cubic metre (3,500 cu ft) stainless-steel temperature-controlled gas chamber as part of these experiments.

[3] Ennor was the first professor appointed by the new Australian National University in Canberra in 1948.

[2] In February 1967, Ennor was appointed Secretary of the Australian Government Department of Education and Science.

[11] Ennor was made a Commander of the Order of the British Empire in January 1963 as a professor of biochemistry at the Australian National University.