Three different questions
Buyers often send a single line: "is it RoHS?" That question hides three separate ones. Which restricted substances are covered, what the terminal finish of the part actually is, and whether there is any obligation to declare under REACH. The answers can differ per part, per package and per manufacturer, so they are best asked separately.
RoHS: what is restricted
The RoHS directive limits a set of hazardous substances in electrical and electronic equipment. The original list covers lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers. A later amendment added four phthalates to the list.
Two details do most of the work in practice. First, the thresholds are set as a percentage by weight in homogeneous material — meaning each material in the part is assessed on its own, not the part as a whole. A small quantity of a restricted substance can therefore matter more than its share of the finished component suggests. Second, the ten-percent-style limit for most substances is different for cadmium, which has a much lower threshold.
Exemptions also exist for applications where no compliant alternative is currently available. An exemption is not non-compliance — but it does mean a part is compliant under an exemption, which is a distinction worth checking if you need to demonstrate compliance downstream.
REACH is a different obligation
REACH is not a substance ban on products in the same way. Its practical effect for a component buyer is the candidate list of substances of very high concern, and the communication duty attached to it: if an article contains a listed substance above the relevant concentration, information has to be provided through the supply chain.
In practice this is why a supplier may return a REACH declaration or a substance statement separately from a RoHS certificate. They are answering different questions.
Lead-free: process and finish are not the same thing
"Lead-free" is used loosely for two separate attributes:
- The assembly process — lead-free solder alloys, which melt at higher temperatures than tin-lead and therefore need a different reflow profile.
- The terminal finish of the component — the coating on the leads, pads or balls that will actually be soldered.
A part can be lead-free in finish and still be described with the word "leaded" in other contexts, and a lead-free assembly using a tin-lead finished component is a genuine mismatch. Ask about the finish specifically.
Reading the finish marking
Terminal finishes are marked with an industry code consisting of a letter and a digit, defined by the IPC/JEDEC J-STD-609 family of standards. The two you will meet most often:
- e3 — tin. The most common and lowest-cost finish.
- e4 — precious metal, containing no tin. Typically nickel-palladium-gold, used where a tin finish is undesirable.
Other codes cover tin-zinc and other alloys, and the full mapping belongs to the standard rather than to memory. The marking on the reel or box is a pointer: confirm the finish against the manufacturer's datasheet for the exact ordering code, because the same base part number can be offered with different finishes, and the suffix is what distinguishes them.
What to ask a supplier for
- The declared finish for the exact ordering code, not the family
- A certificate of compliance or declaration of conformity, with its issue date
- Whether compliance depends on an exemption, and which one
- A REACH substance statement if your market requires one
- Date code and lot information, so the declaration can be tied to actual material
Where the labelling misleads
- A compliant logo on a listing is not a certificate. It states an intent; the declaration is the evidence.
- Mix-ups on the line. Lead-free and tin-lead parts look alike. If both are in the building, separate storage and clear labelling matter more than the paperwork.
- Base number confusion. Two parts differing only in a suffix can differ in finish — see our guide to reading a part number.
- Age. A declaration issued years ago may not cover the material in front of you.
- Different markets, different rules. RoHS is often used generically, but other jurisdictions maintain their own regimes. If you ship into several markets, confirm which one a declaration actually addresses.
Compliance questions on a real part
At YILUDA TECH every listed part is 100% original, new and unused, with no refurbished or counterfeit material, held in stock at our Shenzhen warehouse and shipped worldwide by DHL, FedEx or UPS. Incoming inspection and traceability documentation are available on request.
Send the full ordering code with quantity and destination and we will confirm availability, pricing and lead time. Our guide to checking components for counterfeits covers what to verify at goods-in, and you can browse the full component inventory.