alarm
alert
attention
beware
bio
bio hazard
biohazard
biologic
biological
biology
black
careful
caution
chemical
covid19
damaged
danger
dangerous
death
disease
element
epidemic
flu
forbidden
grunge
hazard
hazardous
icon
illustration
infection
isolated
mark
notice
pandemic
pictogram
pollution
protection
restricted
risk
safety
science
scientific
security
sign
signal
symbol
toxic
virus
warning