Sustainable Plastics Terminology

These definitions are listed in ISO (International Standardization Organization) accreditations relevant to plastics sustainability. Online sources and date accessed are referenced at the bottom of this page.

Activated Sludge

Biomass produced in the aerobic treatment of waste-water by the growth of bacteria and other microorganisms in the presence of dissolved oxygen.

Agglomerate

Shredded and/or granulated plastics material in the form of particles which cling together.

Anaerobic Digestion

Process of controlled decomposition of biodegradable materials under managed conditions where free oxygen is absent, at temperatures suitable for naturally occurring mesophilic or thermophilic anaerobic and facultative bacteria species, that convert the inputs to a methane rich biogas and digestate. Note 1. In a second phase, the digestate is typically stabilised by means of a composting (aerobic) process.

Baling

Process in which plastics waste is compacted and secured as a bundle to facilitate handling, storage and transportation.

Biodegradation

Degradation caused by biological activity especially by enzymatic action leading to a significant change in the chemical structure of a material.

Biological Recycling

Aerobic (composting) or anaerobic (digestion) treatment of biodegradable plastics waste under controlled conditions using micro-organisms to produce, in the presence of oxygen, stabilizing organic residues, carbon dioxide and water or, in the absence of oxygen, stabilizing organic residues, methane, carbon dioxide and water.

Commingled Plastics

Mixture of materials or products consisting of different types of plastic.

Compost

Organic soil conditioner obtained by biodegradation of a mixture principally consisting of various vegetable residues, occasionally with other organic material, and having a limited mineral content.

Compostability

Property of a material to be biodegraded in a composting process.

Compostable Plastic

Plastic that undergoes degradation by biological processes during composting to yield CO2, water, inorganic compounds and biomass at a rate consistent with other known compostable materials and leaves no visible, distinguishable or toxic residue.

Composting

Aerobic process designed to produce compost.

Contaminant

Unwanted substance or material.

Degradation

Irreversible process leading to a significant change in the structure of a material, typically characterized by a loss of properties (e.g. integrity, molecular mass or structure, mechanical strength) and/or by fragmentation, affected by environmental condition, proceeding over a period of time and comprising one or more steps.

Depolymerization

Chemical reversion of a polymer to its monomer(s) or to a polymer of lower relative molecular mass.

Disintegration

Physical breakdown of a material into very small fragments.

Energy Recovery

Production of useful energy through direct and controlled combustion.

Environmental Sustainability

State in which the ecosystem and its functions are maintained for the present and future generation.

Filler

Relatively inert solid material added to a plastic to modify its strength, permanence, working properties or other qualities, or to lower costs.

Flake

Plate-like regrind.

Fluff

Filament-like regrind.

Home Composting

Practice performed by a private individual with the aim of producing compost for his own use.

Maturity of Compost

Assignment of the maturity of a compost based on the measurement of the maximum temperature in a self-heating test using Dewar vessels. (Wiki)

Maximum Level of Biodegradation

Degree of biodegradation, measured in percent, of a chemical compound or organic matter in a test, above which no further biodegradation takes place during the test.

Organic Constituent

Chemical constituent that contains carbon covalently linked to other carbon atoms and to other elements, most commonly hydrogen, oxygen or nitrogen. Allotropes of carbon, such as diamond, graphite, carbon black, fullerenes and carbon nanotubes are not considered as organic constituent.

Organic Recycling

Aerobic (composting) or Anaerobic (digestion) treatment of plastics waste under controlled conditions using microorganisms to produce, in the presence of oxygen, stabilized organic residues (compost), carbon dioxide and water or, in the absence of oxygen, stabilized organic residues (compost) methane and carbon dioxide.

Post-Consumer

Descriptive term covering material generated by the end-users of products, that has fulfilled its intended purpose or can no longer be used (including material returned from within the distribution chain). The term ‘post-use’ is sometimes used synonymously.

Pre-Conditioning

Pre-incubation of an inoculum under the conditions of the subsequent test in the absense of the acclimatization of the microorganisms to the test conditions.

Pre-Consumer

Descriptive term covering material diverted during a manufacturing process. This term excludes re-utilizing material, such as rework, regrind or scrap that has been generated in a given process and is capable of being reclaimed within that same process. The term ‘post-industrial material’ is sometimes used synonymously.

Total Dry Solids

Amount of solids obtained by taking a known volume of test material or compost and drying at about 105 degrees centigrade to constant mass.

Ultimate Aerobic Biodegradation

Breakdown of an organic compound by micro-organisms in the presence of oxygen into carbon-dioxide, water and mineral salts of any other elements present (mineralization) plus new biomass.

Volatile Solids

Amount of solids obtained by subtracting the residues of a known volume of test material or compost after incineration at about 550 degrees centigrade from the total dry solids content of the same sample. The volatile solids content is an indication of the amount of organic matter present.

Well Managed Industrial Composting Process

Composting process performed under controlled conditions where the temperature, water content, aerobic conditions, carbon/nitrogen ratio and other conditions are optimized.

Online Sources:

ISO 16929:2021(en), Plastics — Determination of the degree of disintegration of plastic materials under defined composting conditions in a pilot-scale test

ISO 17088:2021(en), Plastics — Organic recycling — Specifications for compostable plastics

ISO 14851:2019(en), Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium — Method by measuring the oxygen demand in a closed respirometer

Date accessed: 10.10.2022

About White Horse Plastics

White Horse Plastics is a UK based injection moulding company specialising in the design and production of tight tolerance components and sub assemblies for the medical, automotive and UK Manufacturing sectors.

We are based in Stanford-in-the-Vale, close to the research laboratories of South Oxfordshire, run 30+ moulding machines in 20,000 square feet of space and employ more than 20 specialist engineers and operators.

In the two years since the management bought out the company, the new directors have committed to promoting the distinctive competence of White Horse Plastics, offering a growing number of UK & EU OEMs world class, small technical components.

We are committed to the lifetime development of our staff – many of us have worked for the company for over 20 years. We are also committed to improving sustainability within our industry and work with a number of supply partners who offer recycled, renewably sourced and sustainable polymer materials. Read more about sustainable options here.