Conflict minerals and 3TG: reporting and supplier declarations

What 3TG means and why it is in your part

3TG stands for tin, tantalum, tungsten and gold. The label comes from their chemical symbols and from the four minerals that regulators grouped together: cassiterite for tin, coltan for tantalum, wolframite for tungsten and gold itself. They are used in solder, contacts, plating, cutting tools, capacitors and alloys.

A buyer of engineered parts rarely purchases these minerals directly. They arrive inside a plated contact, a solder joint, a machined insert or a specialist alloy. That distance is the problem. The further a mineral sits from the finished part, the harder it is to say which smelter processed it.

Conflict minerals reporting exists because the trade in these minerals has been linked to armed conflict and forced labour in parts of Central Africa. The rules do not ban the minerals. They require companies to investigate their supply chains and report what they find.

The rules a buyer is likely to meet

The best known framework is Section 1502 of the US Dodd-Frank Act, which led to the SEC conflict minerals rule. It applies to companies that file with the SEC and whose products contain 3TG necessary to function. Those companies then push the question down to their suppliers, which is how a small machining supplier ends up completing a form for a large customer.

The EU has its own regulation, 2017/821, which places due diligence duties on importers of tin, tantalum, tungsten and gold at defined volumes. The EU framework uses the OECD Due Diligence Guidance as its reference. The UK and other markets have their own expectations, often through customer codes of conduct rather than a single statute.

The practical point is that the rules differ in scope, but the request to a supplier looks similar: identify the minerals, identify the smelters and say whether they are validated as conformant. That request is what most buyers actually manage.

Customer codes of conduct often go further than the statutes. A large OEM may require a CMRT for every part, an annual refresh, a named responsible person and a stated policy on smelters that are not yet conformant. Those contract terms bind a supplier even where the local law does not.

What a supplier declaration should contain

The common industry form is the Conflict Minerals Reporting Template, usually called the CMRT. It asks for company details, the reporting year, the parts or product scope, the minerals present, the smelters and refiners used, and the origin information the supplier holds. A separate template, the EMRT, covers extended minerals such as cobalt and mica.

A usable CMRT names the smelters by their validated identification. It states the reporting year. It says whether the declaration covers all products or only the ones supplied to you. It is signed and dated by someone accountable for the answer.

The mineral list should match the part. If the supplier declares tin but the part is gold plated, ask why. If the supplier declares no 3TG at all for a solder-bearing assembly, ask for the basis of that answer rather than filing it.

Smelters, refiners and the limits of a form

The smelter is the choke point in the chain. A conformant smelter has been assessed against a recognised audit programme, such as the Responsible Minerals Assurance Process. A supplier that buys from an audited smelter can pass that assurance up the chain with more confidence than one that buys from a trader.

A CMRT that lists no smelters but claims full conformance is a contradiction. It may mean the supplier has not done the work, or that the minerals are recycled or scrap. Both answers are possible, but the supplier should say which.

Do not treat the form as a certificate. It is a snapshot of what the supplier knows at a point in time. The value comes from the smelter list, the reporting year and the supplier's ability to explain how the list was built.

A due diligence sequence that holds up

Start with a policy that says what you require and who owns the answer. Map the parts and materials that could contain 3TG. Send the CMRT to each supplier with a clear scope and a deadline. Review the response for completeness before you accept it.

Then test the answer. Compare the smelter list with the published conformant lists. Check the reporting year. Ask for the supplier's own due diligence process if the form is thin. Where a smelter is unidentified, ask the supplier to contact its own supplier and set a date for a better answer.

Record the outcome by part and by supplier. If the risk cannot be resolved, escalate through the corrective action process. A red flag is not proof of a problem, but it is a reason to keep asking until the chain is clear.

What to collect, and from whom

The table below maps the documents to the tier that normally holds them. It is a starting point for a request, not a legal opinion.

In practice, most of the useful evidence sits with the direct supplier, even when the mineral is further upstream. That supplier may not mine or smelt, but it chooses its own sources and can pass the question back. The buyer's influence is the purchase order and the contract, not a direct relationship with a smelter.

Red flags and how to close them

A red flag is a signal that the declared chain does not add up. Examples include a smelter that is not on any recognised list, a country of origin that conflicts with the smelter location, a declaration that covers every product with no detail, and a supplier that cannot say who its own metal source is.

The response should be proportionate. Ask a focused question, set a response date and record the answer. If the supplier is a distributor, push to the manufacturer. If the manufacturer buys through a trader, ask for the trader's declaration. Each step should narrow the gap between the part and the smelter.

If the gap remains, decide whether to accept the risk with a written rationale, change the material or change the supplier. Document the decision. An unresolved red flag with no record is worse than a documented exception, because it shows the process had no owner.

Keep the record current

Conflict minerals data ages quickly. A declaration for an old reporting year tells you little about the current shipment. Ask for an update at least annually, and sooner if the supplier changes a plater, a solder or a material source.

Store the declaration with the part record, not in a shared folder with no index. Link it to the supplier record and to any change notification. When a new revision changes the plating or the solder, treat it as a trigger to refresh the declaration.

The aim is not a perfect form. It is a chain of evidence that lets you answer a customer question without starting from zero. A current CMRT, a smelter list and a named owner cover most of the work.