alert

area

attention

background

biohazard

biological

black

caution

chemical

chemistry

control

danger

dangerous

destructive

disease

door

doors

environment

epidemic

harmful

hazard

hazardous

health

hospital

icon

illustration

infection

information

isolated

medical

pandemic

pollution

protect

protection

risk

safety

scientific

sign

sticker

substance

symbol

toxic

triangle

virus

warn

warning

waste

weapon

yellow

zone