ISO/CD 25303.2

Plastics — Determination of the degree of biodegradation and disintegration of plastics under wet anaerobic digestion conditions

Scope

This document specifies a method of determining the degree of biodegradation and disintegration of plastics when exposed to wet mesophilic or thermophilic anaerobic-digestion conditions. This method is based on ISO 13975, amended with a modified approach to determine disintegration.
This method is designed to simulate typical anaerobic digestion conditions for wastewater sludge, the organic fraction of mixed municipal solid waste, manure, or agricultural waste. The test product is exposed in a laboratory test to an inoculum derived from anaerobic digesters operating on wastewater sludge, pre-treated household waste, manure, agricultural waste, or a mixture thereof. The anaerobic decomposition takes place under low-solids (less than 15 % solids) and static non-mixed conditions. 
NOTE 1 While many wet anaerobic digestion systems have a pretreatment system designed to retain large, solid products from entering the digestion phase, it cannot always be guaranteed this removal is 100 %. It can therefore be useful to know to what extent plastics are biodegrading and disintegrable under these conditions.
NOTE 2 This test method is written for “plastics” but can also be used for other product groups (e.g. packaging).