Microplastics

Drinking water, indoor and outdoor air, household dust, synthetic textiles, food packaging, tire wear, degraded plastic products

Microplastics are small plastic particles generally defined as less than 5 millimeters (5,000 micrometers) in size. They include primary microplastics, which are intentionally manufactured as small particles, and secondary microplastics, which form through the breakdown or wear of larger plastic products. Microplastics can originate from synthetic textiles, packaging, tires, personal care products, and other consumer materials. They have been detected in food, drinking water, air, and human biological samples. Their chemical composition varies depending on the parent polymer and may include additives, residual chemicals, and substances absorbed from the surrounding environment. Microplastics are a diverse group of particles rather than a single chemical substance, and their potential effects depend on factors such as particle size, shape, polymer composition, and associated chemicals. Examples include plastic microbeads, synthetic microfibers, and small particles made from polymers such as polyethylene, polypropylene, and polystyrene. Microplastics are subject to several regulations aimed at reducing their intentional addition to consumer products and release into the environment. In the United States, the Microbead-Free Waters Act of 2015 prohibits intentionally added plastic microbeads used for cleansing or exfoliation in rinse-off cosmetics, including certain over-the-counter products. In the European Union, Commission Regulation (EU) 2023/2055, under REACH Annex XVII, restricts synthetic polymer microparticles intentionally added to products, including cosmetics, detergents, and other formulations, with transitional periods for certain uses. California also regulates plastic microbeads in personal care products and includes microplastics on its Safer Consumer Products Candidate Chemicals List.