Sorting paper and plastic waste in France. Jacky Naegelen/Reuters You may be thinking you are doing the world a service when you toss that used paper towel in the recycle, but really, you shouldn't be.

There's a couple big problems with recycling these paper products.

First, a dirty paper towel or napkin could harbor all kinds of nastiness that could ruin an entire batch of recyclables.

While recycling plants do clean the paper products they receive, there's no way to get the grease out of the paper's fibers.

Recycling plants remix paper into a watery slurry, press it into sheets and dry it out. Since grease isn't extracted during that process, it can show up in the new batch of paper as oily spots or even holes where the oil has repelled the water.

So, products like paper napkins, paper towels, tissues, and anything else that might have come into contact with food, grease, or your filthy, filthy mouth (or any bodily fluids, really) should be trashed entirely to reduce the likelihood of an entire batch of recyclable paper products being contaminated by one greasy paper towel.

But the bigger issue with recycling paper towels and napkins is that many of these products were actually created from recycled paper, so they've already been through the recycling process several times.

Each cycle, the fibers in the paper get shorter. By the time the paper's been reincarnated as a napkin or tissue, the fibers are too short to be used again.

On the bright side, you don't necessarily have to send your paper towels and napkins to the landfill. There are a couple of alternate choices to make your life more sustainable and eco friendly.

Using fewer paper products in general is a good first step — using kitchen towels and handkerchiefs instead of paper products can help.

And secondly, since the short fibers in these products break down easily, they are a great candidate for the compost pile — especially if they're unbleached and not too soiled.

Some experts say you shouldn't compost these paper products if you're seriously sick or if the products are greasy, but others say it's not a big deal. Most caution against chlorine-bleached products, however, because some chlorine byproducts can be detrimental to human and environmental health.

So if you're feeling guilty about tossing those tissues and paper towels, don't. These kinds of paper products, including your toilet paper, are made of paper that's already recycled as many times as it reasonably can be.