They say they're "flushable" on the label, but if you do flush one of those wet wipes or moist towelettes down the toilet it could cause big problems.

Some things that may seam like they're safe to flush may cause major plumbing issues. (Ryan McVay, ThinkStock)

"They're not biodegradable so what happens is they clog pipes, they get hung up on bar screens, when they get hung up on bar screens they impede the flow of the wastewater, they jam and clog pipes," said Chris Riat, senior director of operations at United Water New Jersey.

He said the bottom line here is pretty simple.

"When it comes to fibrous wipes that don't biodegrade, they should not enter the system," said Riat.

Peter Eschbach, the director of communications at New Jersey American Water agrees. He said if one of these wipes gets stuck in a pipe and your sewer line gets clogged it could end up being costly.

"It's going to cause a real problem for you in the house, as your toilet and all that sewage backs up, and that is going to cost a lot of money for a plumber to come in," Eschbach said. "If your toilet gets clogged on the way to the main sewer line that causes backups which then rises back up into the manhole, which can eventually cause a raw sewage spill in the street, and of course no one wants that."

But it's not only wet wipes that cause problems. Eschbach listed several items that should never be flushed down toilets including:

  • A disposable diaper. People don't think it's going to be a problem, but the fact is most disposable diapers are made from material designed to expand when it comes in contact with water. That means your pipe will quickly get jammed.
  • Sanitary napkins. They're just not designed to go down a pipe, they frequently will cause a clog that's expensive to fix.
  • Cotton balls and swabs. They're small and they don't seem like a lot, but the fact is when they get soggy they just don't break down, they'll snag in a pipe very easily and builds into a bigger clog that causes problems.
  • Grease and oil. When cooking oil and grease is poured down the toilet it can cause a big blockage in a sewer line, and it almost looks like a gushy soap that mucks everything up.

He said many older sewer systems have lots of twists and turns, which make them even more likely to clog.

"All it takes is one of these things to get caught and hang up, and the next one comes down, and the next one comes down and you've got a real problem at that point," Eschbach said.