Can a Third-Party Auditor Actually Verify Recycled Content? The PACK Act and RMAA Assume Yes.

HR 7502 recognizes mass balance accounting for chemical recycling "when backed by third-party certification systems and reliable evidence." That clause is where a federal recycled-content claim actually gets its number. The rest of the bill is procedure.

On 1 September 2026 the House Energy and Commerce Subcommittee on Commerce, Manufacturing and Trade advanced two bills by voice vote: the PACK Act (HR 6832) and the Recycled Materials Attribution Act, the RMAA. The coverage framed it as the end of a state-by-state patchwork, which is the part that'll get the headlines and the part I care least about. I build measurement systems for waste operations, and both bills quietly hand a measurement problem to auditors. Whether the auditors can carry it is the whole question, and neither bill answers it.

The clause doing all the work

Start with what mass balance is, because the fight lives in the definition. It isn't a method for physically identifying recycled molecules in a finished product. It's a chain-of-custody accounting rule (bookkeeping, really): certified feedstock goes into a mixed process, typically the pyrolysis or depolymerization step behind chemical recycling and pyrolysis systems, and a ledger attributes a share of the certified input to a share of the output. The molecules are fungible. The credits are not. So the number on your label is set less by chemistry than by which allocation rule the certifier lets you run.

And the allocation rules aren't equivalent. ISCC, the certification system most chemical-recycling projects run on, offers several, and they produce very different answers from the same tonne of feedstock. This is the fork the RMAA steps around by saying "mass balance" without saying which kind.

Under a free or fuel-exempt method, the plastic burned to run the reactor and the fuel fractions that come off it leave the denominator entirely. What's left gets attributed to the polymer output. NRDC, which has spent two years calling mass balance the plastics industry's latest deception, walks through the arithmetic: feedstock that's roughly one part waste to nine parts virgin can be sold as fully recycled. California's attorney general made the same argument in a complaint, describing the credit scheme as deceptive. Europe, meanwhile, looks set to allow fuel-exempt after France and Germany backed off a stricter polymer-only line.

What a third-party audit actually measures

So what's the certificate actually worth as evidence? The PACK Act requires certification from a body accredited under ISO/IEC 17065:2012, the international standard for product-certification bodies. That's a real and useful standard. It tells you the certifier has documented procedures, competent auditors, and no financial stake in the result. It doesn't tell you the number on the label is physically true, because that isn't what a mass-balance audit checks.

A mass-balance audit reconciles a ledger: inputs, conversion factors, outputs, credits issued, credits retired. It's bookkeeping verification, and bookkeeping verification is exactly as good as the allocation rule it's told to apply and the input data it's handed. Feed it a defensible rule and clean receipts and it's strong. Feed it fuel-exempt allocation and a moisture-inflated feedstock weight (and feedstock weight is almost always moisture-inflated) and it'll certify a number no mass spectrometer would confirm. The audit isn't lying. It's answering a narrower question than the label implies. A mass-balance audit verifies the arithmetic, not the atoms.

I keep coming back to a belt-speed vision sync from 2023. When we pushed the belt above about 2.4 meters per second, the motion blur cost twelve points of recall, and the classifier reported the same confident probabilities the entire time. The model was calibrated. The sensor was fine. The physical input had changed underneath a measurement that had no way to know it, and we didn't catch it until we put a strobe on the line. Mass-balance certification has the same blind spot. The ledger reports allocated content, not physical content, and it keeps reporting cleanly while the thing it claims to measure walks out the door as diesel.

Contrast that with the sensing on a sorting line. An optical sorter at least points a near-infrared beam at the actual polymer flying past; a Tomra unit will tell you it saw PET more than a thousand times a second, on the real stream, right now. A mass-balance ledger has no sensor at all. It reconciles a spreadsheet against an allocation rule. Once. That's the gap the phrase "reliable evidence" has to close, and the bill hands the standard for it to the FTC.

Then there's the sampling interval. On an RDF dryer in 2024 I watched a near-infrared moisture model drift about three percent a month, enough that recalibration had to live inside the control loop instead of a quarterly service visit. Ledgers drift too: feedstock contracts change, contamination creeps up, a converter swaps suppliers between audits. An annual certificate catches none of it in the eleven months it isn't looking. If a recycled-content claim is going to be a legal representation under the FTC Act, the verification has to sit closer to continuous than a once-a-year audit, and neither bill says how.

Preemption cuts in both directions

Now the headline. Both bills preempt the state and local claim rules that have multiplied since California's SB 343 started redefining what a recyclable label may say. For a national brand, one federal standard beats fifty, and that's a genuine win. But preemption sets a ceiling as well as a floor. Whatever allocation rule the FTC blesses becomes the number everyone may print, and states lose the tool they'd been using to challenge the loose ones.

And the federal baseline is old. The Green Guides that govern environmental marketing claims today were last revised in 2012. Their recyclable-claims section, 16 CFR 260.12, lets you call a package recyclable without qualification only when collection reaches a "substantial majority" of consumers, which the guides put at sixty percent. That definition predates commercial chemical recycling entirely. The FTC reopened the Green Guides in December 2022, held a workshop on recyclable claims in 2023, then stalled: the docket closed without a new rule. So the reference the whole system leans on has sat frozen for fourteen years, and the RMAA would now direct the same agency to rewrite it within eighteen months to accommodate methods it never contemplated.

A few limits worth stating plainly. Both standards are voluntary, so a producer who makes no claim triggers nothing. The PACK Act covers packaging, not every recycled-content representation in commerce. Preemption reaches labeling rules only; extended producer responsibility programs, infrastructure mandates, and state EPR fee schedules survive untouched. And none of it settles what happens on a contaminated or high-moisture stream, where physical recovery and the certified number diverge most, which is the condition most real material arrives in. The text answers the accounting question and leaves the plant-floor question open.

What to instrument before the guidance lands

Eighteen months isn't long to build a data trail that survives a federal audit, and the operators who'll be ready are the ones already treating recycled content as a measured quantity rather than a contractual assertion. That means mass tickets tied to specific inbound loads, conversion factors backed by yield data instead of vendor defaults, and a ledger that reconciles at the batch level, not once a year. It's unglamorous waste intelligence work, the same instrumentation discipline behind credible zero-waste-to-landfill solutions and any diversion number or ESG figure you'd defend to a regulator. We've watched recycled-content value swing hard with commodity prices, and what a clean bale is actually worth at the MRF is exactly why a certified claim is worth defending, or attacking, in the first place.

So watch the allocation method, not the vote count. Sometime in the next eighteen months the FTC will decide, in guidance, whether fuel-exempt mass balance counts as "reliable evidence." That single choice sets the recycled-content number on every certified label in the country, and it sits in neither bill. Precision is what the audit gives you. Recall, the tonne of plastic that was supposed to be in the package and instead left as fuel, is where the number still lies.

Sources & Notes

• Markup details, the sponsors, and the ISO/IEC 17065 certification requirement come from Resource Recycling's 1 September 2026 report on the subcommittee vote.
• The mass-balance recognition language I quote sits in the bill itself; see the Congress.gov text of the Recycled Materials Attribution Act (HR 7502).
• For the sixty-percent "substantial majority" test and the 2012 vintage of the rule, the recyclable-claims section is 16 CFR 260.12 in the eCFR.
• NRDC lays out the fuel-exempt arithmetic and the deception argument in its critique of mass balance; for the certifier's own framing, ISCC explains the difference between mass balance and attribution.