Edith Humphrey, thought to be the first British woman to obtain a doctorate in chemistry, was his younger sister.

After graduating from college, Humphrey was employed for four years by Heenan & Froude at their Newton Heath iron works before joining Brunner Mond in Northwich as the engineering manager of their refined bicarbonate and crystal department.

Ultimately only ten Humphrey pumps were built for commercial operation, however some continued in service into the 1960s.

[5] After the war, Humphrey returned to consultancy and was associated with Imperial Chemical Industries until his retirement in 1941.

In 1945, Hebert Humphrey moved to Hermanus, Cape Province, Union of South Africa.