area
attention
background
bacteria
bio
biochemistry
biohazard
biologic
biological
biology
black
caution
chemical
contagious
danger
dangerous
element
environment
epidemic
flat
forbidden
genetics
glyph
graphic
hazard
icon
illustration
isolated
lab
laboratory
logo
medical
medicine
protection
risk
safety
science
scientific
security
sign
signal
silhouette
simple
solid
symbol
threat
toxic
virus
warning