advice
alerts
art
biohazard
black
bone
buttons
chemical
computer
curve
danger
data
dead
death
dirty
electricity
fire
high
icons
illustration
internet
nobody
nuclear
office
organism
painting
poisonous
power
radiation
radioactive
religious
road
safety
set
shiny
signs
skeleton
skull
station
steel
substance
symbol
toxic
voltage
war
warfare
warning
yellow