For one of his last acts in 2015, Barack Obama signed a bill that bans what advocates say is an environmentally harmful ingredient included in many personal cleansing products and cosmetics.

The ingredient is so common that nearly every American has it in products in their homes.

Congress passed the Microbead-Free Waters Act of 2015, a bipartisan bill that President Obama signed it into law on December 28. The law puts a ban on an ingredient used in the cosmetics and personal care products industry called “microbeads.” These beads are contained in many bodywashes, toothpastes and soaps and supposedly serve as skin exfoliants.

But there is a problem with these little devices. Activists say they never breakdown as they wash down the drain and the devices end up polluting our waterways.

Scientists say the tiny beads, usually of less than 5 microns in size, flow through our sewer systems but are so small that they aren’t screened out and collected before being dumped into our water ways. Once in our lakes, streams and rivers, scientists say these microbeads get eaten by fish and animals. But since the beads cannot be digested it often ends up killing them.

“In New York state alone, 19 tons of microbeads are washed down the drain each year,” Business Insider recently reported.

“Microbeads are highly damaging to the natural environment and the wildlife that live there,” a press release from the Wildlife Conservation Society says. “Because natural alternatives already exist, a ban on their use in personal care products makes perfect sense.”

According to CNN, “a study published in Environmental Science & Technology reported that more than 8 trillion microbeads were entering the country’s aquatic habitats daily. The volume was enough to coat the surface of 300 tennis courts every day.”

Another recent study claimed that there are 1.7 million microbeads per square kilometer at the bottom of Lake Erie.

Consumers can find out which products likely use the tiny devices by visiting the International Campaign Against Microbeads in Cosmetics website to check out their list of products that likely contain microbeads.

Follow Warner Todd Huston on Twitter @warnerthuston or email the author at igcolonel@hotmail.com