[2] His scientific research in physical chemistry included contributions in calorimetry, critical-state phenomena, preparation and properties of pure hydrogen peroxide, properties of cellulose, and the chemical pulping of wood.

[1][3] In 1946, he was made a Commander of the Order of the British Empire.

[4] In 1947, he was named the director of the newly created DRB biological and chemical warfare research division.

McGill University's Otto Maass Chemistry Building, built between 1964 and 1966, is named in his honour.

[6] To this day there remains a plaque on the building dedicating it to Maass's excellent contributions to "science in defense of his country", widely interpreted as a euphemistic nod to his work on Fuel Air Explosives.