Hey guys, is really not because your storeroom is near toilet or not. In Singapore our moisture level are specially high, any wood will absorb moist and grow mold on it overtime, even if you open your storeroom door always, it's not helping. Mold smells and are toxic, it produce mycotoxins, toxic substances that cause health problems in some people. If you have wood cabinet or shelve you will have to constantly clean them and remove the mold. If you still have a choice, replace them with metal shelves, those that do not rust. Check out this company specialize on storeroom rack. StoreRoomRack.com