magnetic field hazard posted in a laboratory; warning posted: `caution; magnetic field may exceed 5 gauss; do not loiter

accelerator alert america attention beware california caution danger dangerous exceed experiment field gauss hazard hazardous horseshoe icon info information international lab laboratory loiter magnet magnetic magnetism magnets may message not notice particle pictogram posted protection restriction risk rule safety science scientific security shape sign signage signboard states strong symbol triangle united usa warning