explosion
attention
beware
bio
biohazard
biology
caution
chemical
chemistry
circle
contaminated
danger
deadly
environment
epidemic
gas
hazard
icon
lab
laboratory
medical
medicine
nuclear
poison
power
prohibition
protection
radiation
radioactive
reactor
reflection
risk
safety
science
security
set
sign
square
symbol
toxic
triangle
virus
warning
waste
yellow
zone