The majority of his career was spent at Unilever, followed by Marrickville. He also served as a consultant for the New Zealand Dairy Board with a focus on pastry butter and for Abels, New Zealand with a focus on pastry margarine.
In retirement, Hyam focused on dry refining of oils using calcium hydroxide instead of sodium hydroxide. Hyam also had a number of patents awarded to him.
His legacy in the field of fats and oils will be remembered for generations to come.