Engineering Answers / Compliance & Documents
The polymer is not the problem. What gets a silicone part into a REACH question is almost always something added to it, and the declaration is only as good as the list behind it.
Under REACH, a silicone part must declare any Candidate List substance above 0.1% by weight of the article, per Article 33, and SCIP notification applies where that threshold is exceeded. Under RoHS, the ten restricted substances apply to electrical and electronic equipment, with limits of 0.1% by weight in homogeneous material, 0.01% for cadmium. Silicone polymer and platinum cure are rarely the risk; pigments, plasticisers, flame retardants and residual catalysts are where the exposure sits.
Silicone polymer, platinum catalyst and the usual fillers are not where a REACH or RoHS problem comes from. The exposure sits in what is added:
That distribution matters practically, because it means the declaration has to be built at the compound level, per grade and per colour. A generic "our silicone is REACH and RoHS compliant" statement is a claim about a material family, not about the part in the box.
Article 33 requires a supplier of an article to give the recipient enough information to use it safely where a Candidate List substance is present above 0.1% by weight of the article. That is a communication duty, not an approval — nothing is banned, but the customer has to be told.
SCIP requires that information to be notified to ECHA's database where the threshold is exceeded, and the SCIP number is increasingly requested alongside the declaration.
Separately, Annex XVII restrictions apply to certain substances in certain articles regardless of concentration — the polycyclic aromatic hydrocarbon entry for consumer articles that touch skin is the one most likely to reach a rubber part. And Annex XIV authorisation applies to a short list of substances that cannot be used without a grant.
RoHS restricts ten substances: lead, mercury, cadmium, hexavalent chromium, two brominated flame retardants, and four phthalates. Limits are 0.1% by weight in homogeneous material, with 0.01% for cadmium.
Homogeneous material is the key phrase and the one that changes the answer. The limit applies to a material that cannot be mechanically separated — the silicone compound itself, a pigment, a coating, an insert — not to the assembly averaged out. A part that is 99% clean silicone and 1% a non-compliant marking ink is a non-compliant part, because the ink is its own homogeneous material.
Exemptions exist and expire. For silicone parts, the relevant ones are rare, but if a supplier cites an exemption, ask for its entry number and expiry date rather than accepting the word.
| Element | Why it matters |
|---|---|
| Part number and description | A company-level statement cannot be traced to a shipment |
| Compound grade, colour and supplier | This is where the substances live |
| Regulation and list version | REACH declarations date quickly |
| Threshold basis (article weight or homogeneous material) | The two are different calculations |
| Test data or formulation assessment | "Assessed" and "tested" are not the same evidence |
| Lab, report number and date, where tested | Makes the claim checkable |
| Exemptions claimed, with entry and expiry | An unqualified exemption is a liability |
| Signatory and revision | Someone accountable, and a version to compare |
The two lines buyers most often skip are the threshold basis and the evidence type. A declaration that says "compliant" without saying whether it was assessed from the formulation or tested on the part leaves the customer unable to answer the next question in their own supply chain.
A declaration per part number, naming the compound grade and colour, the regulation and the Candidate List version, and the basis of the assessment. Not one certificate for the company, because the company makes several compounds in several colours and the answer differs between them. When a customer's auditor asks why a red part and a natural part carry different dates, the honest answer — a different masterbatch, reviewed at a different time — is much easier to defend than a single document that claims everything at once.
A supplier who can answer all four in a single reply has a compliance process. One who sends a PDF with a logo and the word "compliant" has a marketing document, and it will not survive the first serious audit in your own supply chain.
No, and the question is slightly upside down. RoHS applies to electrical and electronic equipment, so it reaches a silicone part when the part is a component of such equipment — a keypad, a seal in a connector, a gasket in a charger. Once in scope, the ten restricted substances apply at the homogeneous material level. Silicone compounds are usually compliant, but a coloured compound can carry a pigment that is not, which is why the declaration has to be per compound grade rather than per material family.
The Candidate List is updated roughly twice a year, so a declaration is only current as of the list version it references. A declaration dated three years ago may be silent on substances added since. Ask for the list version or the date of the last review, and treat anything older than the latest update as a document that needs refreshing rather than a document that is wrong.
It means the threshold is calculated against the weight of the part, not of the material lot. On a 2 gram part, 0.1% is 2 milligrams, which is small enough that a trace contaminant in a pigment masterbatch could matter. This is why the calculation has to be done on the compound formulation with real loading figures, not assumed from a safety data sheet.