Posted: 4 January, 2024. Written by REAL
REAL continues to certify high quality compost and digestate. This was demonstrated in REAL’s first research paper on plastic contaminants published in 2022. This second research paper, published by REAL this month, shows once again that the levels of plastic contamination in certified compost and digestate are consistently lower than what is required by PAS 100 and PAS 110. This conclusion is underpinned by REAL’s statistical analysis of a recent dataset showing the levels of compliance with the physical contaminant/plastic limits required by PAS 100 (0.12% m/m) and PAS 110 (limits based on nitrogen content can be found in PAS 110 here).
REAL holds the data on plastic contamination in compost and digestate that has been independently certified under REAL’s Compost and Biofertiliser Certification Schemes (CCS and BCS) to end of waste criteria in England, Wales, and Northern Ireland.
The analysis shows that 98.3% of compost samples in England, Wales, and Northern Ireland, taken between 1st January 2022 and 31st July 2023 passed against the PAS 100 limit, and 98.7% of digestate samples passed the PAS 110 limit taken over the same period.
The paper also reports the number of samples that would fail if the Scottish Environment Protection Agency (SEPA) plastic limit was in place across England, Wales, and Northern Ireland. Across samples submitted by CCS producers for routine verification testing and re-testing from 1st January 2022 to 31st July 2023, the failure rate for plastic contamination against the SEPA Limit would have been 6.0%. For BCS operators, the failure rate against the SEPA limit would have been 14.5%, representing a marked difference with the rates for PAS 100 and PAS 110.
During the period the level of plastic contamination in the majority of compost samples fell below 0.02% mass/mass (m/m), and the level of physical contaminants in the majority of digestate samples was 0.36 kg/t, for the same period.
Virginia Graham, Chief Executive of REAL, said:
“We once again take pride in the findings of this statistical analysis of plastic content in compost and digestate. Our research shows that the overall plastic failure rate is very low. This bodes well for producers and consumers who can be assured that the compost and digestate certified by REAL under the CCS and the BCS is of high quality and can safely be spread to land.
Our report ultimately demonstrates that standards and independent assessment against those standards are essential for ensuring good product quality and consumer protection. We will continue to do all that is required to ensure a strict testing regime is applied to compost and digestate before it can be supplied to the markets.”
Justyna Staff, Schemes Director at REAL, said:
“Congratulations to the BCS and CCS team for publishing our second research paper on the quality of certified compost and digestate in relation to plastic levels. It is great news that the levels of plastic contamination in certified compost and digestate are significantly lower than the minimum requirements of PAS 100 and PAS 110. It shows how strong the efforts are to ensure the production of high quality compost and digestate. This paper may prove useful for the Quality Protocol revisions and may also be used by REAL to inform future research or policy developments.”
Jenny Grant, Head of Organics and Natural Capital at REA, said:
“REA supports protecting soils by ensuring plastic contamination is as low as reasonably practicable and industry is committed to continuous improvement. We welcome REAL’s analysis paper as it shows good compliance of certified composters’ and AD operator’s composts and digestates with the current PAS 100 plastics limit and PAS 110 plastics-relevant limits and is useful for informing future discussions."