Microbeads are manufactured solid plastic particles of less than one millimeter in their largest dimension and sometimes as small as ten microns. They are most frequently made of polyethylene but can be of other petrochemical plastics, such as polypropylene and polystyrene. Major applications include as an exfoliating agent in cosmetics, abrasives in toothpastes, and biomedical and health-science research.
Microbeads can pollute water and pose a hazard for variety of wildlife, from insect larvae, small fish, amphibians and turtles to birds and larger mammals, which mistake them for food. This introduces the potential for toxicity not only to these animals but also for other species higher up in the food chain, including humans. As a result of growing public awareness and pressure from environmental organizations, many large companies have already discontinued the use of microbeads in their products, and several countries have banned their use in rinse-off cosmetics, including the U.S., Canada, the UK, France, Sweden, India, New Zealand and Taiwan.