alert
atomic
attention
background
black
caution
chemistry
contamination
danger
dangerous
emblem
energy
environment
error
flat
gold
golden
harmful
hazard
hazardous
icon
illustration
industry
isolated
label
long
nuclear
power
protection
radiation
radioactive
radioactivity
reactor
restricted
risk
road
safety
security
shadow
sign
substance
symbol
technology
toxic
triangle
uranium
warning
yellow