I'd clean it with PBW - start with HOT water and soaking for a few days, then do the sniff test landolincoln suggested.. Unless what was in it before was TOXIC, storing a dry product (like grain) should be OK. Storing any liquid in it might raise concerns.
On Tap: South River Shimmer - Belgian Dubbel; Saison du Rivage; How've You Bean? - Vanilla Porter; White Cap Wit Bier
Conditioning: Russian Imperial Stout;
In Bottles: Oatmeal Stout; Belgian Dubbel; Saison du Rivage; Brown Lager; White Cap Wit Bier; 2012 Merlot
In Fermenters - Amber Ale; 60 Minute IPA;Amarone della Valpolicella.
Next Brew: Fume Blonde