Safe sex can be bad for the environment — if you don’t dispose of your condoms correctly.
It’s one of the larger problems for sewage plants around the world: lovers who toss their used condoms in a toilet instead of the trash. Condoms cause problems by clogging sewage drains around the world.
From London’s infamous “Johnnyberg” to an Austin, Texas, clog that led to a prostitution bust, the latex that protects you from STDs and unwanted pregnancies is costing taxpayers millions a year to unclog from pipes and sewers.
But condoms aren’t solely to blame for sewage backups and overflows. Many things clog sewers, which can lead not only to pricey repairs, but the resulting gunk can also overwhelm treatment plants and get washed out to our waterways and oceans.
Here’s a list of just a few things that experts say not to put in the toilet, along with some alternatives to just flushing it all away.

Grease

If you really want to be terrified of the sewer, don’t just look for Pennywise. Look up “fatberg” on Google.
This is your trigger warning.
“Fatbergs” are fairly common. A 2014 study found that 47 percent of the 36,000 sewage overflows in the U.S. occurred because of fat clogs in sewers. And it happens because the fat you pour down the drain mixes with calcium in the drain pipes and it all globs together like…a big sewer-clogging glob. Ultimately, that buildup can cost thousands of dollars to repair, not to mention that oil and grease from our sewer systems damages our beaches and oceans.
As an alternative: Throw that bacon grease in the waste bin. Or, if you use a lot of vegetable oil when you cook, you can turn your beater into a greaser.

Dental Floss

Typically, what goes in your mouth will end up in your toilet. But there’s a caveat to this rule: dental floss.
Dental floss is made of nylon or teflon and doesn’t biodegrade easily. Eventually, what it turns into is a big ol’ ball of yuck.
“When [floss gets] into the wastewater system [it ends] up balling up into these big clumps and getting the workings of our system stuck or broken,” Andrea Pook, spokeswoman for the East Bay Municipal Utility District, tells the Huffington Post.
As an alternative: Try biodegradable silk floss or a water flosser.

Toilet 2
Small household items that we flush down the toilet add thousands of tons of waste to our oceans.

Tampons

Despite their small size, tampons don’t do well in sewage systems. Their absorbent qualities and the string attached to them makes it difficult to break down in sewage systems.
The best way to dispose of them is just to toss them in the garbage.
“It’s best to simply wrap a used tampon in toilet paper and toss it in the garbage, or, if you’re in a public washroom, place it in the waste receptacle for feminine hygiene products,” Playtex, a company that makes tampons, says on its website.
As an alternative: Try using a menstrual cup like the silicone Diva Cup, which can last up to 10 years.

Medicine

Wastewater treatment plants aren’t designed to filter out medicines. As a result, only half of the drugs people throw down the toilet are actually filtered out by sewage treatment.
In 2002, the US Geological Survey found that 80 percent of stream waters studied were contaminated to some degree with pharmaceuticals or hormones. In a more recent survey, 118 pharmaceuticals were found in 25 treatment plants across the states.
In the Great Lakes, six chemicals were detected frequently and had a low rate of removal in treated water, including an anti-seizure drug and an herbicide.
As an alternative: Stockpile your medicines and then turn them in on Oct. 27 during the National Prescription Drug Take Back Day (the website also has a handy collection site locator tool).

Contact lenses

Contacts might just be little bitty things, but when you figure that more than 45 million people wear them in the U.S. alone, and collectively throw away around 14 billion lenses annually, that adds up to a lot of plastic getting flushed down the john. Making matters worse, contact lenses — like most plastics — don’t biodegrade easily, and tend to break down into microparticles that float into the ocean and add to the 93,000 to 236,000 metric tons of microplastic current in our oceans.
As an alternative: Extended wear lenses…or just get glasses. If you do go disposable, TerraCycle and Bausch + Lomb have partnered to create a free recycling program for some lenses and packaging.