alert
area
attention
background
beware
black
careful
caution
chemical
danger
dangerous
design
electromagnetic
energy
hazard
hazardous
high
icon
illustration
ionizing
isolated
lab
label
laboratory
medical
medicine
non
nonionizing
nuclear
protection
radiation
radio
radioactive
radiotherapy
ray
restricted
risk
safety
security
sign
signal
sticker
symbol
toxic
treatment
triangle
warning
yellow
zone