biohazard danger exclamation point fire flame lightning pictogram radioactivity sign skull symbol warning contamination graphic green illustration logo pollution radiation radioactive shape splatter toxic communication electricity power red safety security symbolic voltage volts white wording air direction flag helicopter roof sky storm tempest vane weather wind beware black call phone prohibition ring round suppression talk telephone board drive move ride skate skateboard cinema cinematize film movie screen shot appearance Flags jolly-roger pirate-flag pirates skull-and-crossed-bones traditional art attention icon lettering octagon post simple start stop traffic vandalism alcohol beverage drink glass pottle tipple wine cup hot pot steam warm