Wherever fireworks, smokeless powder, small arms ammunition, or small arms primers are stored, signs with letters at least 3 inches high on a contrasting background stating “FIREWORKS,” “SMOKELESS POWDER,” “AMMUNITION,” and/or “SMALL ARMS PRIMERS” appropriately identifying that type of material or materials involved, shall be conspicuously posted at any location within a building and at any location within an area outside a building where such materials are stored, and also at such other locations as may be required by the Chief.