A<unk>  or biohazard is an organism, or substance derived from an organism, that poses a threat to (primarily) human health. This can include medical waste, samples of a microorganism, virus or toxin (from a<unk>  source) that can impact human health. It can also include substances harmful to animals.  The term and its associated symbol is generally used as a warning, so that those potentially exposed to the substances will know to take precautions. There is also a biohazard HCS/WHMIS logo which utilizes the same symbol.
In Unicode, the biohazard sign is U+2623 (☣).
Biohazardous agents are classified for transportation by UN number:
UN 2814 (Infectious Substance, Affecting Humans)
UN 2900 (Infectious Substance, Affecting Animals)
UN 3733 (Diagnostic Specimen or Clinical Specimen or<unk>  Substance, Category B)
UN 3291 (Medical Waste)
Biological hazard
Moral hazard
Vaccine controversy
Disequilibrium causes
Off-label use
Bedwetting laboratory findings
Drug resistance
Opportunistic infection