accident
alert
attention
background
barrier
black
building
careful
caution
construct
construction
danger
dangerous
deep
engineering
equipment
excavation
fall
fence
forbidden
hazard
health
high
hole
industrial
industry
information
job
maintenance
notice
outdoor
precaution
project
protection
restriction
risk
rock
safety
sign
signage
site
slip
steel
structure
symbol
warn
warning
work
workplace
yellow