CEN/TC 249/WG 9 - Characterisation of degradability

This document summarizes the state of standardization in the field of biodegradable plastics and plastics products at CEN and ISO level. It explains the underlying scientific principles of biodegradation that provide the foundations for relevant test methods and enters into the merits of the individual tests to explain and clarify the reasons for the adoption of specific solutions and criteria.
This document primarily focusses on standards adopted by CEN covering environmental biodegradation testing and relevant specifications. It also includes information on disintegration and eco-toxicity tests. A full list of the international standards considered in this document is provided in Annex A.
In a second part, this document highlights areas where standardization in this field is currently lacking and where future developments may be anticipated and useful.

This document specifies a method for the determination of the ultimate anoxic biodegradation of plastics made of organic compounds, where the amount of the produced nitrogen and carbon dioxide at the end of the test is measured.
The test substance is exposed to an inoculum stemming from the denitrification tank of a wastewater treatment plant. Testing is performed under defined laboratory conditions.
Claims of performance are limited to the numerical result obtained in the test and not used for making unqualified claims such as "disposable in waste water treatment plants" and similar.

This document specifies the vocabulary, methods for characterization, and templates for reporting about bio-based polymers, plastics, and plastics products (including semi-finished plastics products and composites).
In particular this document covers: terminology, bio-based content, bio-based carbon content, Life Cycle Assessment, sustainability aspects, and declaration tools.
Biocompatible polymers and plastics for medical applications covered by specific provisions are out of the scope of this document.

This European Standard specifies requirements and procedures to determine the compostability or anaerobic treatability of plastic materials by addressing four characteristics:
I)      biodegradability,
II)      disintegration during biological treatment,
III)      effect on the biological treatment process and
IV)      effect on the quality of the resulting compost.
NOTE   For packaging EN 13432 applies.

This European Standard specifies test methods and criteria which are to be applied in order to verify if a solid plastic material can be considered as disposable in waste water treatment plants, i.e. it does not create problems for the environment and for the drainage systems. In order to reach this conclusion it needs be verified that the plastic material under evaluation is biodegradable under aerobic conditions (i.e. susceptible to mineralization) and water soluble or water dispersible.
NOTE   Plastic materials which are shown to be in compliance with this European Standard can be used to produce items which, for their characteristics of water solubility or water dispersibility and biodegradability, can be eventually disposed of in municipal or industrial waste water treatment plants, through the sewage.

This guide provides the vocabulary to be used in the field of polymers and plastic materials and items.
The proposed terms and definitions are directly issued from a scientific and technical analysis of the various stages and mechanisms involved in the alteration of plastics up to mineralization, bioassimilation and biorecycling of macromolecular compounds and polymeric products; i.e polymeric items.
NOTE   The proposed vocabulary is intended also to be in agreement with a terminology usable in various domains dealing with time limited plastic applications, namely biomedical, pharmaceutical, environmental, i.e., in surgery, medicine, agriculture, or plastics waste management.

This Technical Report is intended to summarise the current state of knowledge and experience in the field of biodegradable plastics which are used on soil or end up in soil. It also addresses the links between use, disposal after use, degradation mechanisms and the environment.
Therefore, this document is intended to provide a basis for the development of future standards. Its aim is to clarify the ideas and ensure a level playing field, without hiding possible needs for further research or areas of disagreement among experts.

TC - CEN version of an EN ISO parallel publication.

ISO 14855-1:2005 specifies a method for the determination of the ultimate aerobic biodegradability of plastics, based on organic compounds, under controlled composting conditions by measurement of the amount of carbon dioxide evolved and the degree of disintegration of the plastic at the end of the test. This method is designed to simulate typical aerobic composting conditions for the organic fraction of solid mixed municipal waste. The test material is exposed to an inoculum which is derived from compost. The composting takes place in an environment wherein temperature, aeration and humidity are closely monitored and controlled. The test method is designed to yield the percentage conversion of the carbon in the test material to evolved carbon dioxide as well as the rate of conversion.
Also specified is a variant of the method, using a mineral bed (vermiculite) inoculated with thermophilic microorganisms obtained from compost with a specific activation phase, instead of mature compost. This variant is designed to yield the percentage of carbon in the test substance converted to carbon dioxide and the rate of conversion.