Microplastic is a term used for plastic pieces that are generally smaller than 5 millimeters in size. More precisely, microplastics are often defined as plastic particles ranging from about 1 micrometer (μm) to 5 millimeters (mm) in size. Some experts suggest defining microplastics as particles below 1 mm or even smaller as small micro- and nano-plastics below 10 micrometers (μm). The 5 mm upper size limit is commonly accepted for practical reasons rather than strict scientific evidence.
Key Points about Microplastic Size:
- Microplastics are plastic particles below 5 mm in size in at least one dimension.
- Some definitions use a lower upper limit of 1 mm based on identification and classification practicalities.
- Nanoplastics are smaller than microplastics, generally below 1 micrometer (μm).
- Sizes range from around 1 μm to 5 mm, with particles smaller than 10 μm being referred to as small micro- and nano-plastics in some scientific contexts.
This size range distinction is important because particles smaller than certain sizes can interact differently with biological systems and the environment, affecting their harmful impact.
