Microplastics (often labelled as 'polyethylene' on product labels) are used in some personal care products such as facial scrubs, cleansers and toothpaste. These particles are not retained by wastewater treatment so end up in the ocean. While microplastics aren't thought to be a health hazard to consumers, they are a threat to the marine environment. As microplastics (plastic pieces of less than one millimetre diameter) are indistinguishable from plankton, the potential for ingestion by tiny crustaceans is wide. If these creatures ingest them and are eaten by other larger creatures and so on, microplastics can travel up the food chain. And because polyethylene is well known for absorbing toxins, these toxins could also end up in the seafood we eat like shellfish, white fish and tuna. The three main sources of microplastic in marine environments are: 1) consumer products such as cosmetics, 2) breakdown of larger plastic material, and 3) the shedding of synthetic fibres from textiles by domestic clothes washing. To reduce the amount of microplastic getting into our waterways: