RoHS is one of the most frequently referenced certifications on a relay datasheet and one of the least understood. Here is what it actually restricts, how it touches relay contact and coil materials, and how it differs from CE and REACH.
RoHS — the Restriction of Hazardous Substances Directive — is an EU regulation that limits the use of a defined list of substances in electrical and electronic equipment placed on the EU market. The restricted list covers lead, mercury, cadmium, hexavalent chromium, and two groups of brominated flame retardants (PBB and PBDE), with four phthalate plasticizers added in a later amendment. The restriction applies at the level of a "homogeneous material" within the product — meaning a single component, such as a relay's coil winding or contact pad, is evaluated on its own rather than the finished relay being judged as one average mixture.
For a relay switch, this matters because a relay is a small assembly of several different materials — contact alloy, coil wire and insulation, spring steel, plastic housing, solder joints — each of which is a separate homogeneous material subject to its own check against the restricted substance list. A relay is not RoHS compliant or non-compliant as a single number; it is compliant because every material inside it individually clears the thresholds.
The part of a relay most directly affected by RoHS is the contact material. Relay contacts need to resist arc erosion and welding under repeated switching, and some of the alloys historically used for that purpose — particularly in high-current, high-cycle applications — included small amounts of cadmium for its arc-resistance properties. Under RoHS, cadmium is restricted to a very low threshold, which has pushed most contact formulations toward silver alloys (such as silver-tin-oxide or silver-nickel) that avoid cadmium while still managing contact wear. Certain narrow, high-current use cases have at times qualified for time-limited regulatory exemptions on specific contact materials; because exemption scope is reviewed periodically and can be withdrawn, a buyer should not assume an exemption still applies without checking the current declaration.
On the coil side, RoHS mainly affects solder and wire insulation choices — lead-free solder on the coil terminals and PCB pins, and insulation compounds that avoid the restricted brominated flame retardants. These are largely solved problems across the relay industry today, but they are still a legitimate line item to confirm on older product lines or legacy part numbers that may not have been refreshed since RoHS requirements tightened.
These three labels appear together on capability sheets so often that buyers sometimes treat them as one combined "EU compliance" checkbox. They are not the same thing, and a relay can satisfy one without automatically satisfying another.
| Regulation | What It Covers | Scope of Evaluation |
|---|---|---|
| RoHS | A defined list of restricted substances (lead, mercury, cadmium, hexavalent chromium, PBB/PBDE, certain phthalates) | Electrical and electronic equipment only, evaluated per homogeneous material |
| CE | Electrical safety and, where applicable, electromagnetic compatibility — a broader conformity declaration | The finished product against the relevant EU directives |
| REACH | Substances of very high concern across a much larger candidate list | Almost all manufactured goods sold in the EU, not just electronics |
In practice, RoHS compliance is typically one input feeding into a relay's overall CE declaration, while REACH is tracked and declared separately. Asking a factory "is it RoHS compliant" and treating a yes as covering CE and REACH as well is a common and avoidable mistake.
Because RoHS compliance lives at the material level rather than the finished-product level, the most reliable confirmation is a declaration that is tied to the exact part number and, ideally, backed by material test reports for the contact alloy and coil assembly rather than a one-page company letterhead statement covering an entire product range. When a single relay switch order spans several categories — say, general purpose relays from one partner factory and safety relays from another — each factory's RoHS documentation should be checked independently rather than assumed to be consistent across the group, since different factories may source contact alloy from different suppliers even within the same sourcing network.
This is one of the practical reasons a consolidated sourcing process is useful for multi-type relay orders: the RoHS requirement is specified once at the RFQ stage, and the matching per-part documentation is collected and checked against that specification before the order is confirmed, rather than being chased down separately after goods are already in production.
Tell us the relay type, contact material preference and target market — we confirm the matching RoHS status per order.
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