alarm
alert
ambulance
art
attention
background
badge
building
caution
contour
danger
department
emergency
equipment
escape
exit
fire
firefighter
fireman
flame
flasher
forbidden
hat
hazard
helmet
icon
illustration
isolated
label
ladder
light
line
linear
lineart
medical
no
outline
police
prohibited
prohibition
protection
rescue
risk
safety
sign
siren
staircase
uniform
warning