warning signs

acid alert battery beam biohazard biological black cargo chemistry cold crane cross crossbones danger dangerous ears electric electricity falling field fire flame flammable freeze frozen general hand harmful hatch hazard hook ice icon iron irritant label laser leak lift light load loud loudly machinery magnet magnetic manhole mark material mechanical move noise nonionizing notice nuclear overhead pictogram protection radiation radioactive radioactivity rotate rotating set shock sign slide stairs stop symbol temperature toxic toxicity track trap triangle triangular warning waste yellow