Biohazards Definition



Biohazards are defined as any biological or chemical substance that is dangerous to humans, animals, or the environment. This can include body fluids, human tissue and blood, and recombinant DNA. Because biohazards have the potential to infect anyone who is exposed to them, all human waste should be properly handled and disposed of.

When many of us think of biohazards, our minds automatically wander to the horror movie we watched last weekend – scenes of panic, disease outbreaks, and contamination. Biohazards are not restricted to the movies, however, and can exist almost anywhere: In the food we eat, the water we drink, the air we breathe, even in the blood pumping through our veins.

The 4 Levels of Biohazards Defined

Biohazard symbolThe Center for Disease Control (CDC) groups biohazards into 4 distinct groups:

  1. Biohazard level 1: Agents that do not generally cause disease in healthy humans. An example of a level 1 biohazard would be bacillus subtilis, a soil bacterium that can sometimes cause illness in individuals with weakened immune systems.
  2. Biohazard level 2: These agents can cause severe illness in healthy humans, but can only cause infection through direct contact with infected material or through ingestion. Examples of a level 2 biohazard are HIV, salmonella, and hepatitis B.
  3. Biohazard level 3: Pathogens that cause serious diseases and can become airborne. An example of a level 3 biohazard would be tuberculosis, a lung disease that can be passed from person to person through the air.
  4. Biohazard level 4: Pathogens that cause diseases for which there are no treatments. An example of a level 4 biohazard would be marburg virus, a fatal form of hemorrhagic fever that is transmitted through direct contact with infected body fluids or contaminated objects.

How to Protect Yourself: The best way to prevent illness is to eliminate your exposure to biological agents. Under normal circumstances this can be as simple as washing your hands often, staying up to date on your vaccinations, and regularly sterilizing surfaces in your home and at work.

However, if an extreme circumstance presents itself (a co-worker is involved in a traumatic accident, a friend commits suicide, a loved one falls victim to a violent crime) and you find yourself faced with the cleanup, you should turn to a professional for help.

Aftermath professionally handles blood cleanup, communicable disease decontamination, and specialty sanitization 24 hours a day, 7 days a week. Check out our FAQs to learn more.