What is a biohazard?

A biohazard is defined as a biological substance that poses a threat to health, which includes a wide range of microorganisms such as bacteria, viruses, and other pathogens that can cause illness or disease in living organisms. This categorization emphasizes the potential risk these biological agents represent, particularly in contexts where humans could be exposed, such as healthcare settings, laboratories, or areas where biological research is conducted.

Understanding biohazards is critical in industries dealing with biological materials because it informs the necessary precautions, safety protocols, and regulations to prevent exposure and infection. For instance, biohazardous waste requires specific handling, storage, and disposal methods to mitigate risks to public health and the environment.

The other options focus on different types of hazards. Chemical substances that are toxic and physical hazards present in work environments address other forms of risk, while radioactive waste involves a completely different category of hazards related to nuclear materials. Each category has its own concerns and safety measures, but only the biological substances outlined in the correct choice are classified specifically as biohazards.