Not any longer.

Last week, President Barack Obama signed the Microbead-Free Waters Act, a bipartisan bill that enjoyed overwhelming support in Congress.

The law prohibits the manufacture and sale of any “rinse-off cosmetic that contains intentionally added plastic microbeads.”

A September study published in the journal Environmental Science and Technology found that upwards of 8 trillion microbeads are flushed into United States waters every day.

Those beads, which are by definition smaller than 5 millimeters in diameter, can remain in marshes, rivers and other bodies of water for decades, slowly breaking down and releasing toxins. They can also enter the food chain.

Shrimp can mistake microbeads for food, for example. Smaller particles pass through their digestive systems, but some larger beads can get stuck in their guts and sicken or kill them.

“They eat them like popcorn,” Citadel physiology professor John Weinstein told The Post and Courier in October 2014.

Mr. Weinstein and a team of researchers at The Citadel concluded last year that well over seven tons of plastic are currently decomposing in Charleston harbor. And their study didn’t even measure microscopic and near-microscopic particles.

But whereas some plastic waste is bound to accidentally enter Charleston harbor and pretty much anywhere else, plastic microbeads are an entirely unnecessary — and therefore preventable — source of harmful pollution.

Several large cosmetics manufacturers began voluntarily phasing out plastic microbeads from their products well before the new law was signed. Non-toxic, biodegradable alternatives like fruit seeds can be substituted.

Clean waters and healthy marine ecosystems are critical to quality of life in the Lowcountry.

Getting rid of tiny microbeads is a big move in protecting our coastal environment and the creatures that call it home.