First, since Missouri fails to have full state pre-emption regarding OC, you'll have to personally check if the area you wish to OC in has any ordinances forbidding it. I suggest Sullivan Publications, or Municode. However, it's possible your city isn't listed, so I would then trot down to the local courthouse and ask to see a copy of local ordinances.
I would NOT call or ask the local law enforcement as the answer you'll almost always get is, "No, it isn't legal" or "Don't do it anyway because it will only cause problems.". Either answer has the likelihood of being true as if you would have simply guessed for yourself in the first place.
There are very few places that outlaw OC outside of St. Louis or some places near K.C. that I'm unfamiliar with.Cape Girardo is one.