The biohazard symbol is an image that warns people of possible exposure to biological substances that are harmful to living organisms. These biohazards can be viruses, toxins or medical waste.
The biohazard symbol was created by Charles Baldwin in 1966. At the time, Baldwin was an environmental engineer working for Dow Chemical. More than 40 designs were submitted when Dow was working to develop the symbol.
The Centers for Disease Control has four levels of categorization for biohazards. Level one poses the lowest risk to humans, while level four is extremely dangerous. Labs that handle level-four biohazards must be equipped with state-of-the-art protocols to ensure that no accidental contamination spreads from the lab to the general public.