abstract
alert
atom
atomic
business
caution
circle
classic
clean
clear
danger
design
element
energy
graphic
grunge
hazard
icon
illustration
isolated
logo
modern
multimedia
nuclear
pollution
power
professional
radiation
radioactive
radioactivity
ray
reactor
rubber
safety
science
shape
sign
signage
simple
stamp
studio
symbol
technology
template
uranium
warning
warning sign
web
yellow