Ok, ok, this may not the sexiest of topics but I was recently listening to a podcast about the pollution caused from flushing (either down the toilet or bathroom sink) and it really struck a chord. It’s so easy to toss things down the toilet or down the drain without really thinking about it but turns out, so much of what we harmlessly flush is contaminating our water. Here is what you shouldn’t flush down the sink or toilets along with why:

1. Contact lenses
Not only do they not biodegrade easily but they’re often made of plastic and are believed to be contributing to the growing problem of microplastic pollution.

2. Medicine
Pharmaceuticals are frequently flushed down the drain and are now found in our drinking water, streams, lakes, rivers and oceans – eeeeeeek! Wastewater treatment plants are not designed to filter out pharmaceuticals so please dispose your medicines properly by dropping them off at a pharmacy.

3. Wipes
Almost every disposable wipe package warns users not to flush these down the toilet because they are not bio-degradable. Almost all of them contain rayon or viscose and end up clogging pipes, pumps and littering sewage.

4. Floss
Seems so harmless but dental floss is made of nylon or Teflon and ends up wrapped around all sorts things once flushed down the drains.

5. Condoms
Again, wastewater treatment centers aren’t designed to filter out condoms and they often fill up with water/air creating bigger problems than the contamination of bodily fluids.

6. Tampons
I’ve literally been flushing tampons down the toilet my entire period-having life but it turns out you’re not supposed to and it even says so on the box. Why? Their absorbent materials, including the string, do not break down easily and can’t be processed by wastewater treatment centers.

7. Tissues/paper towels
Facial tissues might seem safe to flush because they look so much like toilet paper. But unlike toilet paper, facial tissues have been treated with a chemical binder that takes time to release and break apart when flushed.

8. Qtips and cotton swabs
Like above, cotton swabs and qtips are also formulated to stay intact and will eventually clog up the pipes.

Moral of the story: when in doubt, don’t flush it and throw it away in the trashcan. If it’s not toilet paper or human waste, it probably doesn’t belong down the drain.