Dental floss may be good for our teeth, but it’s bad for our sewer systems—which is why you should never flush the stringy product down the toilet.

Home toilets are designed with our convenience and hygiene in mind, but some people have taken to using them as de facto trash cans, flushing wet wipes, paper towels, feminine products, and other items. While gone from your bathroom in the blink of an eye, these waste products don’t just disappear into some magical abyss: They end up mucking up our pipes and pumps, causing problems at wastewater treatment plants and, in some extreme cases, merging with congealed oils, grease, fat, and waste to form noxious blobs called fatbergs.

Meanwhile, some wastewater treatment plant employees claim to have discovered everything from baseballs to cash to underwear—indicating that people are flushing far more than just household and sanitary products.

Compared to the objects above, dental floss—which is made from thin strands of nylon or Teflon—seems like it should be the least of any sewage worker’s concerns. And as you ready for bed, it’s probably far easier to toss your floss into the toilet than to remember to regularly empty the tiny trash can under your sink.

But since dental floss isn’t biodegradable, it doesn’t dissolve in its watery grave. Instead, it can combine with clumps of hair, toilet paper, wipes, sanitary products, and other gross stuff to form large clumps that clog sewers and pumps, sanitary companies told HuffPost. These blobs can also combine with tree roots and grease, cause sewage spills, and harm the motors in septic systems.

These instances aren't just inconvenient, they're also costly, as they result "in the need for local agencies that own and operate sewer systems to spend more money on maintenance to keep the sewers and pumps clear,” a spokesperson for the Sanitation Districts of Los Angeles County told HuffPost.

We’re not saying you shouldn’t floss regularly, but from here on out, the only things you should be flushing down the toilet are human waste and toilet paper.

For a clear idea of what other kinds of things shouldn’t be going down our drains, check out the video below, which was created by the City of Spokane Department of Wastewater Management and shared in partnership with the Water Environment Federation.

[h/t The Huffington Post]