Certificates are abundant, evidence is thin.
Compost from three Maine facilities that accepted “compostables” cups, bowls and cutlery came back carrying 209 to 455 micrograms of PFAS per kilogram, roughly 20 to 45 times the level found in compost made from food scraps. Nearly all of the serviceware were properly certified with valid certificates. They were made to disintegrate under industrial composting conditions only. They were never designed to degraded in any given condition.
Here are some specific documents that tend to go missing and why:
1. Test report for the product you’re buying
Compostability standards such as EN 13432 and ASTM D6400 apply to a finished item in a defined thickness, format and colorant system. Disintegration depends on all three. Ask ten suppliers for compostability documentation and they will likely send a certificate belonging to the resin producer, or to a different SKU in the same family.
In the Big Compost Experiment. 902 UK households composted 1,307 items at home and reported the results. Sixty percent of items carrying home-compostable certification did not fully disintegrate, and 46% of submitted items could not be sold as compostable (Purkiss et al., 2022).
Ask for the certificate number, the certifying body’s public listing entry, and the exact product description printed on the certificate. Then check that it matches your purchase order.
2. A radiocarbon result on the finished item
“Bio-based” has a definitive test. ASTM D6866 measures the ratio of biogenic to fossil carbon by radiocarbon analysis, because plant carbon contains carbon-14 and petroleum carbon does not. Commercial laboratories run it routinely.
A high bio-based percentage tells you nothing about biodegradability. And bio-based polyethylene is molecularly identical to the fossil version, so it behaves in the environment in exactly the same way.
3. Life Cycle Assessment
Under ISO 14044. An LCA used to support a comparative assertion disclosed to the public must undergo critical review by a panel of interested parties, with a minimum of three experts. Very few supplier carbon footprints for novel biomaterials clear that bar. Many are single figures generated from generic database entries, because primary inventory data for young feedstocks and small production lines often does not exist yet.
Ask for the functional unit, the system boundary, the data vintage, the share of primary versus secondary data, and the reviewers’ names.
4. Chain of custody
Bio-attributed and recycled-content materials frequently travel on a mass balance model, where certified feedstock enters a shared production system and an equivalent volume of output is attributed to a certified claim. The paperwork and the molecules do not follow the same route. Schemes such as ISCC PLUS operate this way openly, and it is a legitimate mechanism for scaling supply without building parallel plants.
It is also not what most buyers picture when they read “made from certified renewable feedstock.” Ask which chain of custody model applies, whether identity preserved, segregated, controlled blending or mass balance, and ask for the certificate’s scope rather than logo.
5. A complete ingredient list
The Biodegradable Product Institute requires safety data sheets for every ingredient, laboratory results demonstrating under 100 ppm total fluorine, and a signed attestation of no intentionally added fluorinated chemicals, a rule in force since 1st January 2020 (Biodegradable Products Institute).
6. Geolocation
The EU Deforestation Regulation requires operators to supply geolocation coordinates for the plots of land where relevant commodities were produced (Regulation (EU) 2023/1115, Article 9). For bio-feedstock routed through aggregators, including straw, spent grain, agricultural residues and mycelium substrate.
The Rules are Tightening
From 27 September 2026, EU measures under Directive (EU) 2024/825 bar generic environmental claims that cannot be substantiated, and prohibit sustainability labels that are not based on a recognised certification scheme oe established by a public authority. The separate Green Claims Directive proposal has had a rougher path, with Commission signalling in 2025 that it intended to withdraw it and the status remaining unsettled since (Latham & Watkins, 2025).
Ask for certificate, test report, chain of custody and the name of laboratory.
Frequently Asked Questions
Is a certified compostable product automatically free of PFAS?
No. Compostability standards measure disintegration, biodegradation, ecotoxicity and heavy metals. PFAS limits are an additional requirement that some certifiers impose on top of the standard, as BPI did with its 100ppm total fluorine limit from January 2020. Research on compost from facilities accepting serviceware found PFAS at 20 to 45 times the level in food waste only compost. So, request fluorine test results specifically.
What is the difference between bio-based and biodegradable?
Bio-based describes where the carbon came from and is measured by ASTM D6866 radiocarbon analysis. Biodegradable describes what happens at end of life and is measured by disintegration and biodegradability testing under standards such as EN 13432.
Is mass balance certification meaningful?
It is a real, audited accounting method that allows certified feedstock into existing plants without separate production lines. Ask which chain of custody model your certificate uses, so the claim you make downstream matches the claim you actually bought.
References
Biodegradable Products Institute. (n.d.). Frequently asked questions. https://bpiworld.org/faq
Directive (EU) 2024/825 of the European Parliament and of the Council of 28 February 2024 amending Directives 2005/29/EC and 2011/83/EU as regards empowering consumers for the green transition. Official Journal of the European Union. https://eur-lex.europa.eu/eli/dir/2024/825/oj
Goossen, C. P., Schattman, R. E., & MacRae, J. D. (2023). Evidence of compost contamination with per- and polyfluoroalkyl substances (PFAS) from “compostable” food serviceware. Biointerphases, 18(3), 030501. https://doi.org/10.1116/6.0002746
International Organization for Standardization. (2006). Environmental management — Life cycle assessment — Requirements and guidelines (ISO 14044:2006). https://www.iso.org/standard/38498.html
Klöpffer, W. (2012). The critical review of life cycle assessment studies according to ISO 14040 and 14044: Origin, purpose and practical performance. The International Journal of Life Cycle Assessment, 17(9), 1087–1093. https://doi.org/10.1007/s11367-012-0426-7
Latham & Watkins. (2025). European Commission announces intention to withdraw EU Green Claims Directive proposal, although the status remains unclear. https://www.lw.com/en/insights/european-commission-announces-intention-to-withdraw-eu-green-claims-directive-proposal
Purkiss, D., Allison, A. L., Lorencatto, F., Michie, S., & Miodownik, M. (2022). The Big Compost Experiment: Using citizen science to assess the impact and effectiveness of biodegradable and compostable plastics in UK home composting. Frontiers in Sustainability, 3, 942724. https://doi.org/10.3389/frsus.2022.942724
Regulation (EU) 2023/1115 of the European Parliament and of the Council of 31 May 2023 on the making available on the Union market and the export from the Union of certain commodities and products associated with deforestation and forest degradation. Official Journal of the European Union. https://eur-lex.europa.eu/eli/reg/2023/1115/oj
The Carbon Trust. (2026). ECGT Directive explained: What organisations who sell in Europe should know and do. https://www.carbontrust.com/news-and-insights/insights/ecgt-directive-explained-what-organisations-who-sell-in-europe-should-know-and-do
