Microbead

A microbead is a manufactured plastic particle under 1 mm, usually polyethylene, added to rinse-off cosmetics and personal-care products as an abrasive or exfoliant. As a primary microplastic, microbeads enter wastewater directly and pass through treatment plants into rivers and the sea, where filter feeders and zooplankton ingest them. Their small uniform size and additive load made them a target for early plastics regulation: the US Microbead-Free Waters Act of 2015 banned rinse-off cosmetics containing microbeads, and the UK, EU, and other jurisdictions followed with manufacture and sale bans. They are distinct from secondary microplastics formed by fragmentation of larger debris.