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For most of the past decade I have worked along a single value chain: tin. I have followed it from mine sites in Rwanda, through smelting in Kigali, to the traders, refiners and manufacturers who eventually turn it into solder for circuit boards and smartphones.
What struck me early on was not a shortage of data. It was that every link in the chain held its own version of the same shipment. The mine recorded tags and bags, the smelter recorded assays and lot numbers, the trader recorded contracts, and the end buyer received a folder of PDFs. Each record was accurate on its own terms. But, put together, they rarely told one story that an outsider could check. Everyone believed they were sharing information. Writing in Fortune in 1950, William H. Whyte described the same trap: “The great enemy of communication, we find, is the illusion of it.” More than seventy years later, mining supply chains are still full of that illusion. Communities ask whether monitoring results are complete. Investors struggle to compare disclosures prepared under different frameworks. Regulators receive documents they cannot easily verify, and workers rarely see the data that describes their own conditions. Volume is not the problem. Data becomes evidence only when someone else can find it, understand it and check it without having to take the issuer's word for it.
From Records to Evidence
One of the smelters I have worked with shows what that looks like in practice. From late 2020, LuNa Smelter in Kigali, at the time the only tin smelter in Africa conformant with the Responsible Minerals Assurance Process (RMAP), began attaching QR codes to its shipments. Each code links to a blockchain-secured certificate, so a buyer can see origin, weight, certifications and chain-of-custody documents for that specific consignment.
The technology mattered less than what sat underneath it: a licensed chain-of-custody system at mine sites, independent third-party audits, alignment with the OECD Due Diligence Guidance and regional ICGLR certification. The digital layer did not create legitimacy. It made existing legitimacy portable, which matters a great deal to buyers who will never visit every mine site themselves. Built on weak due diligence, the same system would simply have been transparent about the wrong things.
Europe Is Turning Passports Into Law
What began as voluntary pilots is becoming a condition of market access. Under the EU Ecodesign for Sustainable Products Regulation (ESPR, 2024/1781), the central Digital Product Passport registry went live in July 2026. It stores unique identifiers, while the passports themselves stay with the companies that issue them. Product-specific requirements will follow through delegated acts, with iron and steel and aluminium among the first groups in the 2025–2030 working plan.
Batteries come first. From 18 February 2027, electric vehicle, light means of transport and industrial batteries above 2 kWh placed on the EU market must carry a battery passport, with information split between the public, parties with a legitimate interest and authorities. Battery due diligence obligations follow in August 2027, and the Corporate Sustainability Due Diligence Directive applies from July 2029.
For miners and refiners of lithium, nickel, cobalt and natural graphite, the four raw materials covered by the Battery Regulation's due diligence rules, customers will increasingly ask for structured, verifiable data that reaches back to the mine. Copper and other inputs will follow as passports spread to further product groups.
What the UN Transparency Protocol Adds
If every platform and jurisdiction defines its own format, a passport issued in Kigali or Lusaka is unreadable in Rotterdam or London. The United Nations Transparency Protocol (UNTP), developed under UN/CEFACT, tackles this by defining a common, open data architecture rather than building a central platform, so that different systems can read the same data regardless of where or how it was created. Version 0.7 completed public review in July 2026 and version 1.0 is in preparation.
The protocol has no central database. Each company issues and keeps its own data, and anyone further down the chain finds it through the product identifier. In practice, a tin shipment would be described by four linked records: a Digital Facility Record for the mine it came from, a Digital Product Passport for the product and the claims made about it, a Conformity Credential in which an independent auditor confirms those claims, and Digital Traceability Events that connect input batches to output batches, so provenance can be followed through each stage of processing.
Trust comes from how these records are issued. They follow the W3C Verifiable Credentials standard, and a Digital Identity Anchor ties each company’s digital identity to a known public registration, so a buyer can see exactly who made a claim. Issuers also decide what is public, what is shared only with specific roles, and what an auditor can confirm without commercially sensitive figures ever leaving the company. And because the same scan returns structured data to a buyer’s system and a plain, readable page to a person on a phone, the information is as accessible to a community liaison officer as it is to a procurement platform.
For our sector, the UN Critical Raw Materials Transparency Protocol (UNCRMTP) extends this common core with commodity-specific passports, starting with copper, cobalt, nickel and graphite. The aim is for one batch-level record to carry what buyers and regulators now ask for separately: a cradle-to-gate carbon footprint, evidence of responsible sourcing on labour, human rights and environmental impact, a verifiable link to the facility of origin, and the share of recycled content.
What It Takes to Make It Work
Technology is the easier part. In our work, five conditions decide whether digital tools build trust or just add another reporting layer:
Ground truth. Credible site-level processes, audits and grievance mechanisms come first. Digital tools can only carry what has been verified.
Shared identifiers and vocabulary. Products, batches and facilities need persistent identifiers, and claims need to reference recognised standards, so that a carbon or labour figure means the same thing in Kigali and in Rotterdam.
Disclosure governance. Someone has to decide, deliberately, who sees what and when. That is a governance question, not an IT setting.
Translation for people. Communities and employees need information in their own language, at the right level of detail, through channels they actually use. Labour data matters most to the people it describes.
Capacity upstream. Smaller producers and artisanal supply chains need affordable tools and practical support. Without them, passports could shut out the very suppliers responsible sourcing is meant to include
In the tin context, the data has existed for years. What has been missing is a shared way of connecting it, so that a record created at a mine site in Rwanda still means the same thing when it reaches a buyer in Europe or Asia. The tools to do that now exist, and regulation is giving companies a reason to use them. Companies that treat their data as evidence, structured, verifiable and shared with care, will find it easier to keep and expand market access. More data will not close the trust gap on its own. Data that others can find, understand and verify can.
About the author
Dr Aleksandra Cholewa is Chief Transformation & Growth Officer at TDi Sustainability, where she leads work on critical minerals traceability, responsible production and sourcing. An expert in digital tools for supply chain transparency, she holds a PhD in Supply Chain Management (research Focus - Digital Product Passports) and works on practical implementation of digital solutions at every stage of the supply chain. She has worked on the tin value chain for around a decade, including with Luma Holding and LuNa Smelter on responsible sourcing frameworks and RMAP compliance, and contributes to international working groups on mineral supply chain transparency. TDi Sustainability is a London-based advisory firm specialising in sustainability, responsible sourcing and ESG performance across global supply chains
