alarm
alert
area
attention
black
button
caution
chemical
danger
education
emblem
explosive
fire
flame
flammable
forbidden
fuel
gas
hazard
heat
hot
icon
industrial
label
liquid
material
notice
nuclear
oil
packaging
precaution
product
protect
protection
radiation
reaction
red
restricted
risk
safe
safety
security
sign
simple
stop
symbol
warning
zone