Production and analysis methods for pristine and degraded microplastic and nanoplastic reference materials

As most microplastic (MP) and nanoplastic (NP) environmental fate and hazard assessments utilise spherical, monodisperse polymer particles that do not represent the continuum of partially degraded, irregular-shaped MPs in the natural environment, there is a strong need for environmentally relevant test and reference materials (TRMs). Cryomilling approaches can readily generate bulk amounts of MP TRMs >100 μm, but only negligible amounts of TRMs below this size and into the nanoscale (