Hulme clocked 55.37 seconds to finish fourth in the final, which was won by his Great Britain team-mate Luke Greenbank in 54.76.
Russia’s Filipp Shopin was second in 54.81, while Germany’s Mark Ulrich came third in 55.35.
Earlier in the day, Hulme had swam the heats of the 200m IM, where he clocked 2:07.09.
The 18-year-old will be in action again tomorrow when he competes in the 200m backstroke event.
He is ranked second in that event behind Greenback with a time of 2:00.65. Hulme will swim in heat three of four.
Fellow Plymouth Leander swimmers Tom Fannon and Laura Stephens will also be in action tomorrow.
Sprint specialist Fannon goes in the 50m breaststroke, while Stephens will compete in the 100m butterfly where she is ranked sixth out of all the competitors. However, the biggest challenge for her will be to make sure she finishes as one of the top two Great Britain swimmers.