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Resin identification codes: does a number in a triangle mean the pack is recyclable?
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.
Introduction
The numerals 1 through 7, in a small triangle on the base of a plastic container, mark the predominant polymer. PET is 1, HDPE 2, PVC 3, LDPE 4, PP 5, PS 6, and 7 is “other”. The resin identification code asserts nothing about whether the article is collected, sorted or reprocessed where it is sold.
Origin, governance and the standard–statute divergence
The code was developed by the Society of the Plastics Industry (SPI) in 1988, assigning "a numeral from 1 to 7, with a 'chasing arrows' symbol around the number" to identify resin type (ASTM International, 2010). Its original audience was not consumers but industry participants: sorters, reclaimers and handlers who required a rapid visual cue to polymer identity in a period preceding optical sorting.
Governance passed to ASTM International when SPI approached the standards body in 2008. The resulting standard, ASTM D7611, was first issued in 2010 and is maintained by subcommittee D20.95, with the current edition designated D7611/D7611M-26 (ASTM International, 2010; store record, n.d.). Two decisions taken in the ASTM era bear on everything that follows. First, the standard replaced the chasing-arrows enclosure with a solid equilateral triangle, a change attributed in secondary accounts to the 2013 revision and made for the express purpose of severing the code's visual association with recycling (ASTM International, 2013). Second, the standard separated the code from environmental claims: its significance-and-use section states that "Resin Identification Codes are not 'recycle codes'", provides that terms such as "recyclable" shall not be placed in proximity to the code, and states that the presence of a code does not imply that the article is recycled or that systems exist to process it (ASTM International, n.d.). The standard applies to new tooling and does not extend to adhesives, coatings or labels.
Neither decision has propagated into the law that compels the code's use. The Plastics Industry Association's May 2022 survey of state law found that plastic product identification is or has been required in 40 US states, that 36 currently require it for at least some products, typically rigid containers above a size threshold, and that 29 states specify a symbol including chasing arrows in their statutory text (Plastics Industry Association, 2022). Consequently, a manufacturer that follows the current ASTM graphic in those states departs from the statutory specification, whereas a manufacturer that follows the statute prints the association the standard was revised to break. This divergence between standard and statute is a structural feature of the RIC system, and it is not attributable to any conduct on the part of consumers.
The divergence is also not resolvable by either institution acting alone. ASTM can revise its own specification but cannot amend legislation that has incorporated an earlier specification by description; equally, no legislature is obliged to track revisions to a privately maintained standard. Amendment of the mandating statutes in 29 jurisdictions would be required before the standard's graphic and the law's graphic coincided.
Scope of the code's assertion and its limits
The code certifies nothing in the technical sense: no audit, licence or conformity assessment attaches to it. It is a self-applied technical marking whose accuracy rests on the party applying it.
What the code asserts, when correctly applied, is polymer identity, which is information used at several points in the materials system. Reclaimers use it in manual quality control; regulators use it to frame material-specific rules; and material-specific collection instructions, such as an instruction to present "bottles 1 and 2 only", are phrased in its terms. Parties defending the code observe that its failures are failures of misreading rather than of falsity: a polypropylene tub marked 5 is truthfully marked whether or not any facility within a thousand kilometres accepts polypropylene.
The propositions the code does not establish may be stated directly. It does not establish that the item is recyclable; resins 3, 6 and 7 are accepted by few US curbside programmes, and even 1 and 2 are reliably recycled only in bottle form in many systems. It does not establish that the item contains recycled content, the code being silent as to origin. It does not establish that the item is made of a single resin, since multilayer and composite articles carry the code of the predominant resin. Finally, it does not constitute a claim by any party that anything will happen to the article after disposal.
The gap between these two lists is the whole of the interpretive problem. The assertion the code makes is narrow, verifiable in principle from production records, and independent of geography; the assertions readers derive from it concern collection, processing and outcome, each of which depends on infrastructure external to the article.
Evidence on consumer interpretation
The evidence that consumers read the code as a recyclability signal is consistent in direction across the sources located for this article. The US National Academies' 2025 consensus study states that "many consumers are confused by on-product resin identification codes, which use the chasing arrows symbol around a number 1 through 7, as an indicator of a product's recyclability", and lists the codes, together with the chasing arrows, among the "significant causes of consumer uncertainty and misunderstanding" in American recycling (National Academies, 2025). The committee's remedial recommendation, a national recycling label standard providing accurate information about what is widely recyclable, would in substance supersede the code's consumer-facing role.
The pattern is not confined to the United States. The 2020 global mapping of plastic packaging labels prepared for the UN's One Planet Network documented worldwide inconsistency in the use of resin codes and recycling symbols and recommended restricting the chasing arrows to the indication of recyclability (UNEP and Consumers International, 2020). The code operates as a de facto global convention, and the arrows carry the recycling connotation into each market in which it appears.
Two features of the code are identified in this literature as sustaining the confusion. The first is the enclosure: whatever the current ASTM graphic specifies, articles in circulation carry the arrows form in large numbers, and 29 states continue to require it (Plastics Industry Association, 2022). The second is the numerals, which create an impression of gradation, such that consumers infer that lower numbers are "more recyclable" — an inference with no basis in the code's semantics. Neither feature is addressed by a disclaimer in the standard text, because both are properties of the marking as applied to the article rather than of the accompanying documentation.
Interaction with law
The code sits at the intersection of three bodies of law whose requirements do not align.
Mandating law, comprising the state statutes described above, compels the code's presence and, in most states, its legacy graphic. These statutes date largely from the early 1990s and were enacted to serve sorting infrastructure rather than consumer information; their drafting therefore predates the comprehension evidence summarised above.
Claims law treats the code's enclosure as a representation. The FTC's Green Guides make an unqualified recyclable claim, which symbolic use can constitute, deceptive unless facilities are available to at least 60 per cent of consumers or communities (16 CFR § 260.12). California's SB 343 proceeds further, deeming the chasing arrows a deceptive recyclability claim unless statutory access and processing criteria are satisfied (Cal. Pub. Res. Code § 42355.51); that provision has been under preliminary federal injunction since 14 July 2026, although the underlying statute remains in place (National Law Review, 2026). The two bodies of law are directly opposed in their operation, in that California law treats as presumptively deceptive a symbol that other states' laws require. Federal preemption legislation introduced in 2026, proposing uniform national rules, responds to that opposition.
Standards, in the soft-law sense, constitute the third body, and ASTM's instrument is the solid triangle. A standards body may change its specification, but it cannot amend statutes that have fixed the earlier specification in law, nor alter the expectations of the installed consumer base. The RIC accordingly illustrates that a labeling system's meaning, once socially established, lies outside the unilateral control of its formal custodian.
Reform activity: three tracks
Reform proposals addressing the code proceed on three tracks — state, federal and voluntary — which illustrate the levers available against a legally entrenched marking.
The state track runs through California's paired statutes. SB 343 addresses the symbol's claims dimension, deeming arrows-bearing codes deceptive absent access and processing criteria; the provision is enjoined but structurally intact (Cal. Pub. Res. Code § 42355.51; National Law Review, 2026). The state's characterization machinery addresses the information dimension: by publishing material-by-material determinations of what is actually collected and processed statewide, California substitutes an official recyclability record for the inference consumers draw from the code, thereby supplying the administrative groundwork that any deemed-deception regime requires.
The federal track consists of the 2026 preemption bill, the Truth in Labeling legislation introduced in August 2026, whose design responds point by point to the difficulties described above: uniform national definitions in place of the state patchwork created by the code's statutes, tiered access thresholds distinguishing full from qualified recyclability claims, and express exclusion of conversion-to-fuel from the recycling the symbol may assert. Its prospects are uncertain and its committee history, at this article's verification date, empty. Its significance for present purposes is diagnostic, in that parties on both sides of the American labeling debate now treat the resin-code settlement of the early 1990s as the matter requiring resolution.
The voluntary track has already taken effect. The How2Recycle Pro redesign confines arrows iconography to demonstrated wide recyclability (GreenBlue, 2025), and the scheme's per-component labels increasingly perform the consumer-information function that the code performs poorly. The division of labour this implies, under which governed labels carry communication and the code carries residual technical identification, corresponds to the separation the standards custodian attempted in 2013, arriving instead through the label market.
None of the three tracks addresses the installed base: moulded containers whose embossed arrows will circulate for decades irrespective of any statute's fate. Label reform operates on new artwork, whereas the RIC is tooling, and tooling amortises on timescales that no labeling regime has governed. Whatever settlement emerges, the arrows-wrapped numeral will remain physically present in the waste stream after its legal meanings are settled, a persistence that supports the case for the machine-readable identification examined in this theme's digital group.
Summary
The resin identification code addressed a 1988 problem: manual sorters required polymer identification, optical sorting did not exist, and consumer-facing recyclability communication was not an objective of the exercise. Each element that now generates difficulty — the arrows, the numerals, and the permanence conferred by moulding into the container — was consistent with that background.
The context has since changed. Modern materials recovery facilities identify polymers by near-infrared spectroscopy rather than by reading embossed triangles, so the code's operational value to sorting is residual. What remains operationally live is the code's secondary infrastructure: the statutes that reference it, the collection instructions phrased in its numerals, and the quality-control conventions built upon it. That superstructure persists because it is legally and institutionally embedded, and not because the underlying identification function still requires a human-readable mark. The case therefore illustrates how a system's form may be preserved by law after its original purpose has been superseded. The code's consumer-facing salience, by contrast, has increased, so that the code now functions in practice as a consumer communication, and on the documented evidence an unsuccessful one.
The reform options divide into three families. The first is to retire the consumer-visible code and move identification into machine-readable carriers, as digital-marking initiatives propose. The second is to retain the code but complete the separation ASTM began, through solid triangles, statutory clean-up and strict separation from claims. The third is to absorb the code into a governed disposal-labelling scheme in which polymer identity is one input to an instruction rather than a free-standing signal. Which path a jurisdiction takes will depend less on the code itself than on the surrounding regulatory and market choices documented elsewhere in this collection. What no path can undo is the accumulated association: after four decades of use, polymer identification and recyclability assertion are not separated in readers' understanding by drafting alone. The case accordingly indicates that symbols deployed at scale acquire meanings that their designers do not subsequently control.
References
ASTM International (n.d.) ASTM D7611/D7611M: Standard Practice for Coding Plastic Manufactured Articles for Resin Identification. Available at: Open source (Accessed: 18 August 2026).
ASTM International (2010) 'Resin identification', Standardization News, November/December. Available at: Open source (Accessed: 18 August 2026).
ASTM International (2013) 'Modernizing the resin identification code', Standardization News, July/August. Available at: Open source (Accessed: 18 August 2026).
Cal. Pub. Res. Code § 42355.51. Available at: Open source (Accessed: 18 August 2026).
National Academies of Sciences, Engineering, and Medicine (2025) Municipal Solid Waste Recycling in the United States: Analysis of Current and Alternative Approaches. Washington, DC: The National Academies Press. doi:10.17226/27978.
GreenBlue (2025) FAQ: How2Recycle Pro label rollout. Available at: Open source (Accessed: 18 August 2026).
National Law Review (2026) California SB 343 enforcement preliminarily enjoined. Available at: Open source (Accessed: 18 August 2026).
Plastics Industry Association (2022) State Resin Identification Regulation Survey, May. Available at: Open source (Accessed: 18 August 2026).
UNEP and Consumers International (2020) "Can I Recycle This?" A Global Mapping and Assessment of Standards, Labels and Claims on Plastic Packaging. Available at: Open source (Accessed: 18 August 2026).
16 CFR § 260.12 (Recyclable claims). Available at: Open source (Accessed: 18 August 2026).
Note on sources and verification
The date of the graphic change from chasing arrows to solid triangle is attributed in ASTM's own commentary and secondary legal sources to the 2013 revision, but was not confirmed against edition-by-edition text; one secondary source renders the designation inconsistently and has not been relied on. The federal Truth in Labeling bill's provisions (tiered access thresholds; exclusion of conversion-to-fuel) are as documented in the market research conducted for this collection on its August 2026 introduction; the bill text was not re-extracted for this article, and no committee action had been identified at verification. The characterisation of resins 3, 6 and 7 as rarely accepted curbside reflects the National Academies study's discussion and general programme documentation rather than a single quantified source. The claim that modern MRFs rely on near-infrared sorting rather than visual code-reading is standard technical background and is stated here without a dedicated citation.
Last verified: 18 August 2026.