This document specifies procedures for preparing seawater and sediments used in test methods to assess the biodegradation of plastic materials in the marine environment. The screened sediment and sediment-rinsed seawater are prepared to sustain aerobic testing at laboratory scale. The described method is designed to separate sediment-rinsed seawater and sand-gravel sediments from intertidal sediments by wet filtration and seawater flotation. This document does not include steps to enhance the biodegradation of plastic materials by concentrating the natural seawater, adding nutrients to the seawater, and pre-culturing the inoculum.

The methods described in this document are intended to be used in addition to issued ISO standard test methods for evaluating the biodegradation and disintegration of plastic materials. The applicable evaluation test methods are ISO 18830, ISO 19679, ISO 22404, ISO 23977‑1, ISO 23977‑2 and ISO 23832.