A passenger had the container in a carry-on bag and brought it on Monday's flight heading from Atlanta to Charlotte, N.C., said US Airways spokesman Todd Lehmacher.
The St. Louis County seat is smoke-free in most businesses and restaurants as of Thursday, though there are a few exemptions.
Beginning this month, schools are required to combat piracy or risk losing federal funds. The University of Missouri already prohibits the use of all peer-to-peer applications.
At least three shots were fired early Thursday afternoon, no one was injured.
The centerpiece of Missouri's special legislative session is intended to entice Ford Motor Co. to make its next generation of vehicles at the Claycomo assembly plant near Kansas City.