abstract
app
area
art
background
bacteria
badge
banner
bio
biohazard
biological
black
button
caution
circle
concept
creative
danger
dangerous
design
epidemic
flat
geometric
graphic
hazard
icon
illustration
isolated
lab
label
mark
paper
protect
protection
quality
risk
science
seal
security
shadow
shape
sign
stamp
symbol
token
toxic
virus
white
zone