RoHS & REACH (Environmental Directives)

RoHS (Restriction of Hazardous Substances) and REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) form the bedrock of European environmental compliance for electronics engineering. While functionally distinct, both acts — RoHS is a directive, REACH a directly applicable regulation — share a common goal: protecting human health and the environment by strictly regulating the use of toxic chemicals in hardware manufacturing.

Complying with these acts is not a testing exercise; it is exclusively a supply chain and BOM (Bill of Materials) management discipline.

RoHS: Directive 2011/65/EU

The RoHS directive restricts the use of specific hazardous materials in the manufacture of various types of electrical and electronic equipment. Unlike some directives, RoHS compliance is geographically expanding; versions of RoHS now exist in China, California, Taiwan, and Korea, making it a globally required engineering baseline.

The Restricted Substances

As of the RoHS 3 amendment (Directive 2015/863), there are ten restricted substances. The maximum permitted concentrations in non-exempt products are typically 0.1% or 1000 ppm (except for Cadmium, restricted to 0.01% or 100 ppm) by weight of a homogeneous material:

1. Lead (Pb): The most historically significant restriction, driving the global transition from SnPb (Tin-Lead) to SnAgCu (Tin-Silver-Copper, or “SAC”) lead-free solder profiles in SMT manufacturing.
2. Mercury (Hg)
3. Cadmium (Cd)
4. Hexavalent chromium (Cr6+)
5. Polybrominated biphenyls (PBB) (Flame retardants)
6. Polybrominated diphenyl ether (PBDE) (Flame retardants)
7. Bis(2-ethylhexyl) phthalate (DEHP) (Plasticizer)
8. Butyl benzyl phthalate (BBP) (Plasticizer)
9. Dibutyl phthalate (DBP) (Plasticizer)
10. Diisobutyl phthalate (DIBP) (Plasticizer)

Engineering Implications of RoHS

• Homogeneous Material Rule: The 0.1% limit does not apply to the whole PCB assembly. It applies to every mechanically disjointable substance. For example, the plastic housing of an IC, the plating on its pins, and the die attach adhesive within the IC are all evaluated individually.
• Reflow Profiles: Lead-free (RoHS) solders require higher reflow temperatures (e.g., peak ~245°C–260°C) compared to legacy tin-lead solder (~215°C). The thermal design of the PCB and the moisture sensitivity level (MSL) of all components must be strictly managed to prevent popcorning or delamination during assembly.
• Exclusions and exemptions: Military and space equipment, means of transport and active implantable medical devices are outside the scope of RoHS altogether (Article 2(4)), so leaded solder remains possible there, e.g. to avoid tin whiskers (conductive crystalline structures that grow on pure tin surfaces and cause short circuits); for equipment in scope, time-limited Annex III/IV exemptions still allow specific uses of lead, such as high-melting-temperature solders (entry 7(a), expiring in 2027).

REACH: Regulation (EC) No 1907/2006

While RoHS is specific to electronics and targets ten compounds, REACH applies to all products (including clothing, furniture, and chemicals themselves) and manages thousands of substances. It places the burden of proof on companies to demonstrate that the substances they use are safe.

Key REACH Concepts for Hardware

For electronics manufacturers, REACH compliance centers entirely around Articles (objects given a special shape, surface, or design, like a PCB assembly) and SVHCs (Substances of Very High Concern).

1. SVHC Candidate List: The European Chemicals Agency (ECHA) maintains a constantly growing list of SVHCs (carcinogens, mutagens, reproductive toxins). The list is updated whenever new SVHCs are identified — most recently on 4 February 2026, with the next update anticipated by ECHA for June 2027 — whereas the RoHS substance list has not changed since 2015 (its exemptions, however, are amended regularly).
2. The 0.1% Threshold: If any component within your product contains an SVHC in a concentration above 0.1% weight by weight (w/w), you have legal obligations.
3. SCIP Database: If SVHCs are present >0.1%, any supplier of the article (producer, assembler, importer or distributor) must submit a notification to ECHA’s SCIP (Substances of Concern In articles as such or in complex objects (Products)) database under Article 9(1)(i) of the Waste Framework Directive 2008/98/EC. This ensures waste operators have data for end-of-life recycling; a pending Commission proposal (COM(2025) 986) would repeal this database.

Official References

• Directive 2011/65/EU (RoHS) — Full text — EUR-Lex, Official Journal of the European Union
• Delegated Directive 2015/863 (RoHS 3) — Phthalates amendment — EUR-Lex (adds 4 phthalates to restricted substances list)
• Regulation (EC) No 1907/2006 (REACH) — Full text — EUR-Lex, Official Journal of the European Union
• SVHC Candidate List — Substances of Very High Concern — European Chemicals Agency (ECHA), last updated 4 February 2026