Testing for material biodegradability

SATRA is launching an innovative new compostability and biodegradability testing programme in collaboration with our partner Authenticae.

Businesses are increasingly searching for viable end-of-life solutions for their products to meet their sustainability goals. The testing and analysis of compostability and biodegradability alongside SATRA and Authenticae’s combined expertise can play a crucial role in helping members to develop solutions that could ultimately turn discarded products into compost which, in turn, can be used to grow nutritious crops, replenish farmland soil and sequester carbon from the atmosphere. Initially developed for leather, the tests have also been successfully trialled and applied to a range of other materials.

The following tests are now being offered to SATRA members:

Quick screening: A cost-effective way of ruling out materials that will not make it through more demanding test protocols. The material is placed in a controlled environment simulating industrial composting for 20 days, and any samples performing well in this evaluation can then be selected to progress onto further testing.

Disintegration test: An assessment employed to determine if a material disintegrates to a sufficient degree to be recognisable as compost. The material is placed into a controlled environment simulating industrial composting for at least three months, with relevant observations being recorded in line with ISO 20200:2015 – ‘Plastics. Determination of the degree of disintegration of plastic materials under simulated composting conditions in a laboratory-scale test’ (SATRA can offer an adjusted version of the test for leather and other materials).

Ecotoxicity test: A test used to check for any substances of concern which may be present in the material once it has disintegrated. This assessment can therefore be utilised to evaluate how safe any resulting compost would be when added to a particular ecosystem. The material is placed into a controlled environment simulating industrial composting for 90 days. The resulting compost is then analysed for a standard ecotoxin screen to highlight metals, pesticides, solvents, oils/greases, phytotoxins, persistent bio-accumulative and toxic substances (PBTs) and a number of other substances.

Plant Response test: An evaluation of how well plants grow and respond to being grown in compost containing the material. The material is shredded into tiny particles and is placed in a controlled environment for 90 days. Following this period, the compost is mixed with other growing media and selected plant species are grown in it. Twenty-eight days later, the growth parameters of the plants (such as total mass, number of leaves and presence of any abnormalities) are compared to control plants grown at the same time.

Biodegradability test: A leather-specific evaluation (ISO 20136:2020 – ‘Leather. Determination of degradability by microorganisms’) selected to determine biodegradability by using microorganisms. The leather is ground up and added to a bacteria ‘soup’, and the amount of carbon dioxide (CO₂) produced is constantly monitored and measured through infrared detection. This is compared to a control specimen to understand how biodegradable the material is.

Future issues of SATRA Bulletin will explain in greater detail each of these tests and what the results mean, as well as exploring how they can be used to develop more sustainable products.

Publishing Data

This article was originally published on page 18 of the February 2022 issue of SATRA Bulletin.

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