National Marker Company sign with legend âCAUTION â TRIPPING HAZARDâ is mostly used at construction sites and other premises to mark potential tripping hazard zones like slopes, wet floors, and rocky territory. This caution sign displays the message in bold yellow text on black base and black text on yellow base to ensure better visibility in most lighting conditions and even from a distance. The rectangular caution signage complies with OSHA standards and has NMC Sign Muscle coating to protect the text against fading, scratches, scuffing, mold, and moisture.