RoHS — Restriction of Hazardous Substances

RoHS is an EU directive (2011/65/EU, amended by 2015/863/EU) that restricts the use of specific hazardous materials in electrical and electronic equipment (EEE). It limits lead (Pb), mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), and four phthalates.

Why companies use it

·Mandatory for all EEE placed on the EU market — non-compliant products cannot be sold in Europe legally
·Reduces environmental and health impacts of electronic waste containing toxic metals
·Many non-EU markets (China RoHS, Turkey AEEE) have adopted equivalent regulations, making compliance globally relevant
·Drives supply chain transparency: manufacturers must know the material content of every component they use

What hiring managers look for

·Electronics engineers and compliance engineers must understand which materials are restricted and which exemptions apply
·Managing RoHS compliance through the supply chain (IPC-1752A declarations, SDoC) is a practical skills requirement
·Knowing the exemption list (Annex III and IV) is important — some applications (medical, military, aerospace) have specific exemptions
·Understanding the interaction between RoHS and REACH (SVHC) shows breadth of regulatory knowledge

Typical interview questions

What are the ten substances restricted by RoHS 3 (2015/863/EU)?

What is the maximum allowed concentration of lead (Pb) under RoHS?

How do you ensure that your BOM (Bill of Materials) is RoHS compliant when components come from multiple suppliers?

What is the difference between RoHS and REACH, and how do they interact?

Are medical devices exempt from RoHS? What is the current regulatory position?

Common mistakes

·Assuming RoHS only applies to lead in solder — there are ten restricted substances across all materials in the product
·Not maintaining supplier Declarations of Conformity (DoC) — compliance must be documented and auditable
·Ignoring homogeneous material concentration limits — RoHS limits apply to homogeneous materials (each individual material layer), not to the whole component
·Confusing RoHS compliance (EU directive) with IEC 62321 (the analytical test method standard) — they are related but separate
·Not tracking exemption expiry dates — time-limited exemptions can expire during a product's manufacturing lifetime

Real engineering example

An electronics manufacturer was surprised when a routine EU customs check flagged their power supply as potentially non-compliant. Investigation found that a third-party capacitor supplier had changed their internal dielectric material to one containing DEHP (a phthalate restricted under RoHS 3), without issuing a change notification. The manufacturer had not been monitoring supplier material change notifications systematically. Implementing a formal supplier change notification (SCN) process and annual material declaration renewal prevented recurrence.

Topics covered

RoHSEU directivehazardous substanceslead-freecomplianceWEEEelectronics

Related interview guides

Electronics Engineer →Manufacturing Engineer →Mechatronics Engineer →