Question

What is hazardous waste?

Answer 1

Waste that is useless and only continues to cause harm to the environment or system.

Explanation:

Nuclear power plants are good examples of hazardous waste.

Once nuclear fuel is used, the waste material is then useless for anything else, but it is still radioactive and dangerous, so it needs to be disposed of in a safe way.

You can also get hazardous waste within an organism, once a biochemical reaction has happened and there are certain substances left over that will only cause harm, such as ammonia or carbon dioxide.

In human respiration we produce `CO_2`, which we can't then use further, and so we need to rid ourselves of it by exhaling. This is another example of hazardous waste in a different context.