You're fire extinguisher will be fine as long as it is functional. Check the cooks handbook if there is one for whatever sanctioning organization the event is being held under.
22" WSM & Kettle
Former owner: Jambo, Klose BYC, Med. Spicewine, Pitts & Spitts, XL & (2) Med. BGE's, (2) 18" WSM's