On October 14, Urban Mining Industries and S3 Markets announced the issuance of Environmental Attribute Certificates for Pozzotive, the ground-glass pozzolan Urban Mining produces in Beacon Falls, Connecticut — described in the release as the world’s first EACs issued for a supplementary cementitious material. The mechanism is book-and-claim: the environmental attribute of the material is separated from the material itself, so a buyer whose projects sit far outside Pozzotive’s shipping range can acquire its emissions-reduction attributes without a single tonne changing hands.
Book-and-claim is not a gimmick. It is how renewable electricity attributes have traded for two decades, and it is how sustainable aviation fuel certificates work today. But in every market where it has become credible, the certificate rests on published paperwork: a defined unit, a methodology anyone can read, a named verifier, and a retirement record a stranger can inspect. The Pozzotive launch, on its public materials, currently offers none of those four. That does not make the claim false. It makes it unsubstantiated — and for a compliance reader deciding whether the claim can enter a Scope 3 inventory, a bid, or a marketing line, the difference is the whole job.
The material underneath is real. Its paperwork is from 2020.
Pozzotive itself is not vaporware. It is post-consumer glass milled to a fine powder, used to replace a portion of portland cement in concrete. Sales in 2025 were reported at more than 20,000 tons; its largest application to date is the JPMorgan Chase headquarters tower in Manhattan, built with roughly 52,000 cubic yards of Pozzotive concrete. The product has a genuine track record as a material.
The documented basis for its carbon claim is thinner and older. The quantitative evidence in public is a pre-production screening LCA from around 2020, which puts Pozzotive’s footprint at 56 kg CO2e per tonne against a U.S. industry-average portland cement figure of 1,040 kg CO2e per tonne. That study was written before the plant was in production, from engineering estimates — and it says so, describing a three-phase plan that was supposed to end in a product-specific, third-party-verified Type III EPD built on twelve months of actual production data. As of this month, no such product EPD for Pozzotive can be found in the public EPD sources. What exists are EPDs for concrete mixes that contain Pozzotive, which is a different document about a different product.
Readers will meet the headline figure in three versions: 93% lower (the October release), 95% less (the screening LCA, per tonne against industry-average cement), and 94% less (a project case study, against a different cement average of 922). The spread is not necessarily dishonest — the percentages move because the denominator moves. But a certificate programme has to fix one denominator, one functional unit, in writing. So far, none is fixed.
One tonne of Pozzotive is not one tonne of avoided cement emissions
The certificate’s value is determined by displacement, and displacement is arithmetic with two inputs a buyer should be able to reproduce. A tonne of Pozzotive avoids emissions only to the extent that, in an actual mix, it replaces clinker-bearing cement at an achieved replacement rate without the total binder content rising to compensate. At a 1:1 replacement against the industry-average factor, the screening numbers imply roughly 984 kg of avoided CO2e per tonne. Use a manufacturer-specific cement factor — the screening LCA itself notes real cements run closer to 800 kg — and a realized replacement rate below 1:1, and the figure falls materially.
Two details in the launch language deserve a careful read. The release says issuance accounts for “the potential SCM replacement rates.” Certificates issued against potential displacement are a different instrument from certificates issued against realized displacement. And Pozzotive is also marketed as a functional filler for paints, coatings, adhesives, and polymers — end uses that displace no cement at all. If certificates are issued on production tonnes rather than on tonnes verified in cementitious use, the counterfactual under part of the issued volume can fail entirely. The issuers say an adjustment methodology exists. It is not published.
What credible book-and-claim looks like
The precedent ledger is instructive because the credible systems all converged on the same five elements: a fixed physical unit tied to a verified production event; serialization in a registry the seller does not unilaterally control; retirement as the exclusive, third-party-visible claim event; an independent verifier working to a named standard; and written rules for what the physical buyer of the underlying product may claim.
Renewable Energy Certificates have the full stack — metered generation, regional registries, retirement, Green-e oversight, and GHG Protocol quality criteria. SAF certificates have it: the fuel is certified first under ISCC or RSB, and a not-for-profit registry run by RMI, EDF, and partners handles issuance and retirement. The RIN market under the Renewable Fuel Standard shows the cost of building the stack late — fraudulent credits for fuel never produced cost obligated parties more than $200 million before the EPA imposed third-party quality assurance, with buyers bearing the loss on invalid credits even when they bought in good faith. And the closest cement precedent, Microsoft’s 2025 agreement to buy Sublime Systems’ cement with its EACs separable by book-and-claim, specified independent third-party verification as a headline term — while still describing the registry infrastructure as a future system being built.
Against that template: the Pozzotive certificates are issued on S3 Markets’ own platform, held in S3’s custodial accounts, and retired on S3’s ledger. S3 describes its infrastructure as “aligned with” the ISO 22095 book-and-claim model and as “mapping to” the AIM Platform’s v1.0 standard — its own verbs, self-declared, with no conformance assessment by either body referenced. The release does not state what one certificate represents. It names no verifier and no assurance standard. It publishes no registry a third party can search. None of this proves the underlying tonnes are wrong. All of it means an outside reader currently has to take the seller’s word for the seller’s product.
The fault line specific to this launch: the physical product already carries the claim
Generic double counting is not the sharpest risk here. The specific one is double claiming between the certificate and the concrete. Pozzotive’s low footprint already flows, today, into the environmental product declarations of the concrete mixes that physically contain it — claimed, properly, by the producers and project teams who bought the material. If the same tonne’s attribute is also sold as a certificate to a distant buyer, the benefit exists in two ledgers at once: once in a project-level mix EPD, once in a certificate retirement.
Every mature book-and-claim system answers this with a written allocation rule: when the attribute is sold separately, the physical product is de-characterized — its buyers must report it at a default factor, because the low-carbon attribute now belongs to someone else. The Pozzotive launch materials state no such rule. Until they do, a certificate buyer cannot know whether the attribute they retired is exclusively theirs, and a physical buyer cannot know whether the EPD benefit they are reporting has also been sold. This single document — the attribute-allocation policy — is the fastest credibility win available to the issuers, and the first thing a competitor, an auditor, or a journalist will ask for.
The accounting rules have not caught up — and the pitch has
Whatever the paperwork eventually shows, a buyer today should be clear about what the certificate can legally do inside an inventory. Under the GHG Protocol’s current Scope 3 standard, the answer is: nothing. That standard is an attributional, physical-flow inventory; market-based instruments exist only for Scope 2, under quality criteria. There is no current mechanism by which a book-and-claim certificate for a material you did not physically buy reduces your reported Scope 3 Category 1 footprint. Netting one in today is ahead of the standard, not compliant with it.
The rules are moving — which is precisely why claim language matters now. The GHG Protocol’s Actions and Market Instruments workstream has proposed multi-statement reporting: the physical inventory stays foundational, a market-based statement would extend contractual instruments to Scopes 1 and 3 (its materials expressly name commodity certificates for cement), and in the interim companies are instructed to report the figures separately, without netting. A consultation on the draft standard is scheduled for Q2 2027. SBTi’s revised standard moves the same direction: EACs for commodities usable at activity-pool or sector level, reported separately from the inventory, as an interim progress instrument. As this desk noted when California’s climate deadline held while the federal one slid, reporting regimes right now are a set of clocks running at different speeds — and a certificate bought against tomorrow’s rules carries restatement risk under today’s.
Set against that, S3’s buyer-facing language promises “valid, defensible Scope 3 reduction claims.” Those words are doing more work than the current rulebooks allow. The AIM Platform’s v1.0 framework — the market-built quality bar — caps any intervention claim at the quantity of the component actually in the reporter’s own inventory and requires the intervention to be associated with the reporter’s value chain; S3 says its infrastructure “maps to” AIM, which is a self-assessment, not an evaluation against those tests.
What to demand before the claim holds
For a compliance reader meeting this certificate in an inventory, a supplier file, or a bid, the substantiation requests are concrete. Each one is answered by a document, not a conversation:
- The certificate definition sheet — what one EAC represents, in what unit, against what functional basis.
- The issuance methodology — the cement baseline factor, the replacement-rate rule (realized, not “potential”), and whether issuance requires verified cementitious end use.
- Serialization with a public retirement record — a lookup a third party can run, naming the beneficiary and date of retirement.
- The attribute-allocation policy — the written rule for what physical buyers of uncertificated Pozzotive may claim in their EPDs.
- The product-specific Type III EPD — third-party verified, built on production data, under the new consolidated cementitious PCR; or an explicit acknowledgment that the factor still rests on the 2020 screening study.
- The verifier’s name and standard — an ISO 14065-accredited body with a published verification statement, or clarity that verification is the platform’s own process.
- The invalid-certificate clause — who makes the buyer whole if a batch is later found over-issued; the RIN market’s default answer was “nobody,” until the rules changed.
- The accounting treatment, in advance — your assurance provider’s concurrence that the certificates will be reported separately from the physical inventory, before the purchase, not at audit. If the claim will be marketed in California, an AB 1305 applicability review belongs in the same file; in the EU, note that certificates cannot support a consumer-facing climate-neutral product claim at all under the Empowering Consumers Directive, whatever their quality.
The fork
None of this argues against the instrument. Cement is a spot market with thin margins, novel SCMs struggle to finance capacity, and a long-term attribute revenue stream is a rational answer — it is the additionality story that makes the financing narrative credible, especially for forward purchases funding new capacity. The GHG Protocol is building a home for exactly this instrument class. The direction of travel is not in doubt.
What is in doubt is only whether this launch does the paperwork. It becomes credible if a product EPD publishes, the methodology is public, a named accredited verifier attests issuance, and retirements become inspectable by strangers. It fails if certificates turn out to be issued on production tonnes regardless of end use, if the physical product keeps its EPD benefit in parallel with the certificate, or if “Scope 3 reduction” marketing keeps outrunning the separate-statement treatment every relevant rulebook currently requires. Both paths are still open. Which one the issuers choose over the next two quarters is the story — and it will be decided by documents, so ask for the documents.
