‘Bio’ is short for biological and biohazards are hazardous substances which can injure or kill people or animals. The most common types of biohazards are linked to medicine and to hospitals or laboratories in particular. Medical waste is a prime example of a biohazard. People are most likely to be affected when a biohazard liquid is spilt and comes into contact with their skin. That is why rubber gloves, special protective glasses and lab coats or similar are worn by people working in these situations. Such protective clothing greatly reduces the possibility of injury or illness.
Biohazards are not all the same. While all are hazardous some are more hazardous or dangerous than others. Low level biohazards can cause symptoms similar to those caused by food poisoning. More serious biohazards can cause diseases such as measles, mumps and even influenza but because millions of childhood vaccinations have been given, the danger of these biohazards is still relatively low.
When humans are required to work with bacteria associated with SARS, malaria and TB, the work environment is sealed and full protective clothing is worn. In addition modern medicine has antidotes for these biohazards should they cause an infection.
Finally some biohazards can cause injury and death to animals though not to humans. Bird flu and Ebola are two examples of the possible consequences of some biohazards. But the average person will rarely if ever find themselves in a situation where such biohazards are present.