Medicine
In comparison with the other examples, this one will not harm your drains, but the environment and even the ones around you. If you throw your medicine down the drain, your pipes won’t be at risk of being clogged, but the chemicals of the medication will enter the environment and represent a danger to others.
As the United States Geological Survey states, people, throw more than 4,000 types of prescription medicine, which can only affect the environment, pollute groundwater and soil, and hurt marine life.
On top of that, some chemicals might even be drunk by others. If you don’t know where to throw your medication, there are free drop-off sites for that, and if not… use the trash can.