New parents take heart: A little poop might not be the worst thing you find in diapers these days, as far as the environment is concerned.

It’s estimated that the four million babies born in the United States each year are wrapped in as many as 20 billion disposable diapers annually. Disposed up in landfills, those dirty diapers account for 3.5 million tons of waste, according to a 2016 U.S. Environmental Protection Agency estimate. Once these diapers reach the landfill, the National Oceanographic and Atmospheric Administration estimates that it takes 450 years for them to decompose. And that’s just in the U.S.

The Dirt on Disposables

What’s breaking down in these diapers? It isn’t just human waste and plastic, since many diapers are manufactured using chlorine, which prevents bacteria, the key ingredient in landfill decomposition.

The same chlorine that helps create toxic pollution in landfills can cause irritation to your baby’s skin.

The irony is that one of the primary functions of chlorine is to make products like paper and diapers look white, even though white is probably the last color you’d associate with a used diaper.

Chlorine-Free Diapers

Chlorine-free disposable diapers are becoming more widely available, manufactured by companies such as Seventh Generation. Other chlorine-free products are available for your baby, including wipes and training pants for tots of potty-training age. With the volume of baby products you’ll probably throw away during your child’s lifetime, it’s worth the investment to seek more eco-friendly baby products.

Editor’s note: Originally published on January 12, 2009, this article was updated in October 2018.

By Trey Granger

Trey Granger is a former senior waste stream analyst for Earth911.