abstract
alarm
alert
ambulance
background
beacon
black
building
bulb
business
danger
door
doorway
emergency
equipment
escape
evacuation
exit
factory
fire
japan
lamp
light
lighting
office
panel
police
red
rescue
safety
security
sign
siren
sound
speaker
staircase
stairs
stairwell
subway
train
train station
wall
warning
way
white