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Marine and soil biodegradability: can the claims be made at all?
Marks and reference graphics are shown for identification, academic research and commentary. The image does not grant permission to apply a scheme mark to packaging; consult the issuing body's current eligibility and artwork rules.
Claims without a consensus standard
Most certified claims in this section rest on a consensus standard: named thresholds, a certifier, a seal. Marine and soil biodegradability claims do not. The specification that once anchored marine claims was withdrawn more than a decade ago and has not been replaced. What remains are test methods without pass/fail criteria, proprietary scheme benchmarks, and one standardised use — agricultural mulch film — narrower than the general claim.
Marine claims after the withdrawal of ASTM D7081
For a period, marine biodegradability was addressed by ASTM D7081, a standard specification for non-floating biodegradable plastics in the marine environment, which stated defined requirements that a product could meet or fail. ASTM withdrew D7081 in 2014, and no successor specification has been issued (ASTM, n.d.a). What survives at ASTM is D6691, a standard test method for determining aerobic biodegradation of plastics in the marine environment using a defined microbial consortium or natural seawater inoculum. D6691 measures a biodegradation rate under laboratory marine conditions; being a method rather than a specification, however, it contains no threshold that constitutes "passing" (ASTM, n.d.b). The method has itself continued to be revised: a registered work item, WK82370, revised the 2017 edition, and the current designation stands at D6691-24a, which indicates continuing method development rather than an imminent specification (ASTM, n.d.b).
The division of labour between methods and specifications is accordingly the operative distinction. A test method determines how a property is to be measured; a specification determines how much of that property is sufficient. A marketer in possession of D6691 data holds a number, expressed as per cent conversion over a test period in a laboratory inoculum, but holds no consensus criterion by which that number is converted into a claim. Whoever supplies the criterion therefore functions as the standard-setter, and since 2014 the criteria have been supplied by the certification schemes themselves.
Scheme-owner criteria in the absence of consensus specification
The operative marine and soil marks are TÜV Austria's OK biodegradable family — MARINE, WATER and SOIL — inherited, as the OK compost schemes were, from Vinçotte. Their structure follows conventional certification practice: defined test regimes, accredited laboratories, licensed conformity marks and policed usage. They differ from the compostability marks examined earlier in this group in the provenance of their criteria. Whereas OK compost certifies against EN 13432, a public, consensus and harmonised standard, the OK biodegradable schemes certify against benchmarks that the scheme owner has itself set, drawing on available test methods while supplying the thresholds, environments and timescales by proprietary decision (TÜV Austria, n.d.).
That difference concerns the source of authority rather than the rigour of testing. The schemes' criteria are published, their testing is carried out in accredited laboratories, and their boundary discipline is consistent with the certifier's compostability practice: the OK compost HOME rules expressly forbid use of that mark to claim soil or water degradation, routing such claims to the dedicated schemes (TÜV Austria, 2024). A consensus standard distributes the power to define "biodegradable in soil" across a committee of interests and exposes that definition to public revision, whereas a scheme-owner criterion concentrates the same power in the certifier. Consequently, purchasers of the claim, regulators incorporating it and consumers reading it all rely on one organisation's determination of what the open environment requires, and no independent specification exists against which that determination can be checked.
EN 17033 and the bounded case of mulch film
One consensus specification for soil biodegradation does exist. EN 17033, covering biodegradable mulch films for agriculture, states quantified requirements (EUR-Lex-cited in sector practice; CEN catalogue). Its existence establishes that such standards can be written; its scope indicates the circumstances in which one has been. Mulch film is a product designed to be left in soil, in a defined use, by professional users, and in a context where recovery of the film is the alternative being priced. The standard covers that application rather than "soil biodegradable" as a general packaging claim, for which no consensus document exists (see verification note).
The regulatory perimeter
Around this unanchored centre, claims law draws an increasingly tight perimeter, and it does so through three distinct legal mechanisms in three jurisdictions.
In the United States, the FTC's Green Guides govern. An unqualified degradable claim is deceptive "if the items do not completely decompose within one year after customary disposal", and such claims are deceptive outright for items customarily landfilled, incinerated or recycled, since those destinations "do not present conditions in which complete decomposition will occur within one year" (16 CFR § 260.8(c)). The provision bears on marine and soil claims through its reference to customary disposal. Packaging's customary disposal routes are landfill, incineration and recycling, whereas the ocean and the field are not disposal routes but accidental destinations. A marine-degradability claim on a consumer package therefore either mispredicts the item's customary fate or, if read as reassurance concerning litter, falls to be assessed as an unqualified claim under the one-year test.
In the European Union, the perimeter is drawn by adjacency rather than by a provision addressed to marine or soil claims directly. The oxo-degradable ban, upheld in the Symphony litigation on findings that included the marine-environment conclusion that fragmentation outpaces biodegradation (EUR-Lex, 2024; see the oxo article), constitutes the adjudicated European record on open-environment claims resting on incomplete biodegradation. The general claims regime bears on loose "biodegradable" marketing through the Empowering Consumers Directive's per se prohibitions on generic environmental claims made without demonstrated excellence (Directive (EU) 2024/825). Moreover, the packaging regulation's compostability provisions channel biodegradation claims toward industrial composting and impose mandatory warnings against disposal in nature (Regulation (EU) 2025/40), the legislature thereby declining to treat the open environment as a disposal pathway that packaging law should validate.
California imposes a further domestic restriction: its labeling statutes restrict the use of "biodegradable" and cognate terms on plastic products sold in the state, a regime that predates and complements its compostability rules (CalRecycle, n.d.).
Dimensions on which a scheme-owner criterion may be examined
Where certification substitutes for consensus, the content of a claim is determined by the certifier's criteria document, and five dimensions of that document carry most of the information it discloses.
Specification of the environment. Biodegradation rates diverge by orders of magnitude between seawater at the interface, the water column and sediment, and between agricultural soil and litter scenarios. A criterion that names its milieu with laboratory precision therefore states a testable requirement, whereas environment designations of a generalised kind, such as "nature" or "the open environment", correspond to the formulations at issue in the Symphony record.
Conversion and period. The compostability standards' architecture, in which a quantified carbon conversion must be achieved within a stated timeframe, supplies the template. A criterion stating disintegration without biodegradation, or omitting the period over which conversion is measured, has not stated a biodegradability requirement.
Method and inoculum. Test methods such as D6691 permit defined-consortium and natural-inoculum variants of differing severity (ASTM, n.d.b). The criterion's choice between them, together with its temperature regime, determines the distance between the laboratory condition and any actual sea.
Exclusions. Some schemes state the boundaries of their claims expressly; the certifier's own HOME rules barring soil and water assertions are an instance of the practice (TÜV Austria, 2024). The presence of explicit exclusions is evidence that a scheme is administered for conformity rather than for marketing.
Consequences of failure. Licence revocation, surveillance testing and code-traceable marks distinguish certification from endorsement, and their absence leaves the mark without an enforcement mechanism.
Examination along these dimensions does not yield a conclusion about a mark's merit; it locates the mark on a range extending from a quasi-standard, in the sense of a criterion that is published, quantified, bounded and policed, to an assertion supported by none of those features. In the absence of consensus specifications, that range constitutes this claim family's governance.
Semantics of certified and uncertified claims
Against this background, the practical content of marine and soil claims may be stated as follows.
A certified OK biodegradable SOIL or MARINE mark asserts that the specified formulation met the scheme owner's published criteria in accredited testing for that environment. It is a traceable and revocable attestation of conformity with a private benchmark. It does not assert conformity with any consensus standard, none existing for packaging, nor performance in any particular sea or field, whose temperatures, biology and mechanics the laboratory inoculum approximates at best.
An uncertified "marine degradable" or "biodegrades in soil" claim asserts, in most markets, whatever its maker can substantiate under general claims law, which, following the withdrawal of D7081, cannot include conformity with a consensus marine specification. Under the Green Guides' one-year completeness test, such claims are presumptively fragile; under EU claims law, presumptively generic.
Neither form of claim addresses littering. Where a degradability mark is read as permission to discard the item in the open environment, a materials property is converted into a behavioural licence that the evidence surveyed here does not support. The compostability schemes' mandated warnings against disposal in nature, and the EU's requirement of them, respond directly to the inference from "biodegradable" to "harmless when littered".
Three governance trajectories from a common starting point
Set beside its neighbours, the marine and soil family completes a comparison in which three branches of open-and-managed-environment biodegradability have met three different governance outcomes from a common starting point.
Compostability began, as marine degradability did, as an unstandardised marketing claim. It subsequently acquired consensus specifications (EN 13432, ASTM D6400), certification schemes built on those specifications, and finally statutory incorporation, completing the sequence because industrial composting is a controlled environment whose conditions a laboratory can reproduce.
Oxo-degradability followed the opposite course. Unable to demonstrate complete biodegradation in any environment, it was not standardised but prohibited, its claims banned outright in the EU and its litigation defeat furnishing the adjudicated record against fragmentation-based marketing.
Marine and soil claims occupy an intermediate position. They have not matured into consensus specification, because the open environment, unlike the compost vessel, cannot be reduced to a single reproducible test condition; and they have not been extinguished, because materials engineered for biodegradation in soil and aquatic applications exist and the mulch-film precedent establishes that their claims can, in bounded uses, be specified with quantified requirements.
The comparison supports an inference, identified here as inference rather than as a finding of any cited source. Where a biodegradability claim's target environment is controlled and reproducible, the compostability sequence of standards, certification and statute is the more likely trajectory. Where the claim's commercial utility depends on the environment remaining unspecified, the regulatory outcome recorded for oxo-degradability is the more likely one. On this reading, the marine and soil claims most likely to persist are those following the path of EN 17033, narrowing to defined products, defined environments and defined professional uses until a consensus criterion becomes writable, and claims that resist such narrowing are correspondingly more exposed to prohibition than to standardisation.
Summary
Marine and soil biodegradability claims occupy a governance position that differs from the other claim families examined in this theme. They are contested scientifically to a degree that has so far precluded consensus specification: seawater and soil are not single environments, and a threshold appropriate for a Baltic mudflat would not be appropriate for tropical surface water. On that view, the 2014 withdrawal of D7081 represented standards governance retiring a specification that the available science could not sustain. At the same time, the claims remain commercially operative, because materials engineered for aquatic or soil biodegradation exist, serve identified applications, and require some means of differentiation from the oxo-style claims that regulation has extinguished.
Scheme-owner certification currently occupies that position, functioning as a substitute for the consensus instrument that does not exist. Its integrity depends on the features described above: published criteria, accredited testing, boundary discipline, and the certifier's maintenance of marks narrower than its licensees' marketing. Two developments would displace it. The first is scientific consolidation sufficient to allow consensus specifications to return environment by environment, as EN 17033 did for mulch film. The second is a regulatory determination, already visible in the EU's drafting, that open-environment degradability is not a claim that consumer packaging should make. Pending either, marine and soil biodegradability remain as this article has described them: claims supported by tests but not by thresholds, and marks with owners but without consensus criteria, so that the identity of the party stating the criterion carries more of the claim's content than in any other family examined in this theme.
References
ASTM International (n.d.a) ASTM D7081-05 (withdrawn 2014): Standard Specification for Non-Floating Biodegradable Plastics in the Marine Environment. Available at: Open source (Accessed: 18 August 2026).
ASTM International (n.d.b) ASTM D6691: Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in the Marine Environment by a Defined Microbial Consortium or Natural Sea Water Inoculum. Current edition D6691-24a. Available at: Open source (superseded-edition record; see current listing via the ASTM store) (Accessed: 18 August 2026).
CalRecycle (n.d.) Truth in labeling for compostable products (and related plastics labeling provisions). Available at: Open source (Accessed: 18 August 2026).
Directive (EU) 2024/825 of the European Parliament and of the Council of 28 February 2024, OJ L, 2024/825, 6.3.2024. Available at: Open source (Accessed: 18 August 2026).
EUR-Lex (2024) Judgment of the General Court of 31 January 2024, Symphony Environmental Technologies v Parliament, Council and Commission, Case T-745/20, CELEX 62020TJ0745. Available at: Open source (Accessed: 18 August 2026).
Regulation (EU) 2025/40 of the European Parliament and of the Council of 19 December 2024 on packaging and packaging waste, OJ L, 2025/40, 22.1.2025. Available at: Open source (Accessed: 18 August 2026).
TÜV Austria (n.d.) OK biodegradable — certification schemes (MARINE, WATER, SOIL). Available at: Open source (portal to the OK certification family) (Accessed: 18 August 2026).
TÜV Austria (2024) CS-OK02: Certification scheme, OK compost HOME. Available at: Open source (Accessed: 18 August 2026).
16 CFR § 260.8 (Degradable claims). Available at: Open source (Accessed: 18 August 2026).
Note on sources and verification
The withdrawal of ASTM D7081 in 2014 without successor is from the ASTM store record cited. D6691's status as a test method, the WK82370 work item (registered as a revision of the 2017 edition), and the current D6691-24a designation are from ASTM's store and work-item records; whether further revision remains active was not determinable from those records. The characterisation of the OK biodegradable schemes as resting on scheme-owner criteria rather than consensus specifications follows from the absence of any such specification and the schemes' own documentation; the schemes' individual criteria documents were not separately retrieved for this article, and evaluation of a specific mark requires consultation of the current scheme rules. EN 17033's existence and its confinement to agricultural mulch films is stated from the standards literature; its quantitative requirements were not extracted and are not cited. California's restrictions on "biodegradable" terms for plastic products are summarised from CalRecycle's labeling pages; the underlying Public Resources Code provisions were not individually retrieved. § 260.8(c) is quoted verbatim from the eCFR.
Last verified: 18 August 2026.