Chemical makers carry the heavy end of REACH: registering substances they manufacture or import above one tonne per year, under the regulation's "no data, no market" principle. Hardware companies sit at the other end as producers of articles, and their work is mostly informational. The SVHC Candidate List grows as ECHA adds substances (updates typically land twice a year), and each addition can turn a previously quiet part into a declarable one.

Article 33 is the operative duty. If an article contains a Candidate List substance above 0.1 percent weight by weight, you must inform your customer, and you must answer consumer requests within 45 days. The threshold applies at the article level, not the finished product, so a small O-ring with a phthalate plasticizer can trigger disclosure inside a 20 kg machine. Since 2021, such articles must also be notified to ECHA's SCIP database.

The contrast with RoHS is worth keeping sharp: RoHS bans a fixed list of substances in electronics, while REACH, for article makers, is mostly a duty to know and disclose what parts contain. Managing it means collecting supplier declarations against the current list, writing full material disclosure into the specification and supplier qualification process, and refreshing declarations on a cycle, because compliance against a moving list is never one-and-done.