A clogged toilet can quickly go from a minor annoyance to a costly plumbing problem. While a plunger can often clear small blockages, more serious clogs can lead to overflowing water, damaged pipes, and expensive repairs. Fortunately, most toilet issues are preventable. Knowing what should never be flushed is one of the easiest ways to protect your plumbing and avoid unnecessary repair costs.

One of the most common causes of toilet clogs is hair. Unlike toilet paper, hair does not break down in water. Instead, it tangles together and catches inside pipes, trapping other debris and gradually creating stubborn blockages. Baby wipes, makeup wipes, and even products marketed as “flushable” can also cause major problems because they are designed to remain strong when wet and do not disintegrate quickly after flushing.

Other everyday items, including paper towels, facial tissues, feminine hygiene products, cotton swabs, and dental floss, can also damage your plumbing. Paper towels and tissues are made to hold their shape when wet, while feminine hygiene products absorb water and expand, making them more likely to become stuck in pipes. Cotton swabs and dental floss can catch on rough surfaces inside the plumbing system, where they collect additional debris and contribute to difficult clogs.

If something unsuitable is accidentally flushed, acting quickly can help prevent an overflow. Turn off the toilet’s water supply, avoid flushing again, and use a proper toilet plunger. If the blockage remains, adding dish soap and hot—but not boiling—water may help loosen it. For persistent clogs, it’s best to contact a professional plumber. The simplest way to avoid plumbing emergencies is to remember that only human waste and toilet paper should be flushed, while keeping a small trash bin in the bathroom for everything else.