According to a recent piece in The Guardian, a bill was approved by the House of Representatives that would phase out the use of microbeads in products used within the U.S.

While microbeads have use in scientific contexts, such as breaking open cells for DNA and RNA extraction, they have been pervasively appearing in cosmetics and general consumer products in more recent years:

Microbeads may have significant environmental impact, especially within aquatic systems, as these microplastics may be washed down the drain with regularity. In addition, other small micro plastic particles may be formed from the breakdown of larger plastics introduced into these same environments.

The small size of these particles may parallel that of small microscopic organisms and so may be accidentally ingested by zooplankton, or other creatures that filter feed. See the below video capturing a copepod capturing fluorescently labeled beads with the use of feeding currents:

In addition to then biomagnifying up the food chain into other organisms, these fragments have also been shown to both release and absorb pollutants.

So the recent legal action is certainly an exciting victory. See a timeline here of some of the actions that have been leading up the bill.