alarm
alert
area
arrow
attention
beware
careful
caution
construction
danger
dangerous
death
do
electric
electrical
electricity
graphic
hand
hard
hazard
high
icon
illustration
industrial
industry
information
label
not
power
precaution
prohibition
protection
radiation
restriction
risk
safety
secure
security
shock
sign
stop
striped
symbol
touch
typical
unauthorized
voltage
warning
zone