Sejwal, who won two gold and three silver medals in the previous edition of the event, left for the Championship in the wee hours.
Sejwal has been in good form and bagged four gold medals at the National Games in Kerala earlier this year. The Championship in Dubai is, however, his first international outing since the Asian Games in Incheon last year.
Sejwal became only the third Indian in the last 28 years to grab a medal at the Asian Games, when he clinched the 50m breaststroke bronze.