This chapter discusses the term particulate plastics (PPs), which encompasses both micro and nanoplastics, and is therefore defined as ranging from 5 mm down to the nano-meter range. Contamination of terrestrial environments with PPs is continuously increasing and is considered to be one of the major threats to human and animal health. Rapid development in industrial and agricultural activities and overconsumption by humans have sped up the manufacturing of plastic wastes and their consequent disposal into terrestrial and aquatic ecosystems. Particulate plastics are broadly defined as synthetic polymers less than 5 mm in size, and they can be of a primary or secondary origin. Plastic fibers have received considerable attention regarding biodegradable and biosynthetic alternatives. The particulate plastic’s colors also influence how easily they are observed, and therefore can impact their sampling likelihood. PPs that are brighter in color, for example, red, are more likely to be observed and extracted than those that blend into the substrate.