Caution signs point to potential hazards that can result in minor or moderate injuries. Caution signs have a standard yellow background with black lettering. These are used only for hazards that will not cause life-threatening hazards. “Slippery When Wet,” “Work Overhead,” and “Slow—Construction Traffic.” These are just a few of the signs construction sites need. They should be installed around the area of the potential hazard including high-traffic areas and around ongoing work.