RoHS Explained — What Every LED Therapy Device Buyer Needs to Know About EU Hazardous Substance Restrictions
RoHS is often described as a compliance checkbox. But for LED therapy device manufacturers and buyers, it is one of the most consequential directives affecting product design, component selection, and supply chain management. Getting it wrong means your product cannot be sold in the EU — and that is not a marketing problem. It is a legal one.
RoHS — the Restriction of Hazardous Substances in electrical and electronic equipment — is a European Union directive that restricts the use of specific hazardous substances in electrical and electronic products sold in the EU market. It has been in force since 2006, expanded twice, and now covers 11 categories of electronic equipment.
For buyers sourcing LED therapy devices from international manufacturers, understanding RoHS is essential: it determines which materials and components can legally be used in products sold in Europe, and it determines what documentation a manufacturer must be able to provide to demonstrate compliance.
This article is written from the perspective of an LED therapy device OEM manufacturer — explaining what RoHS covers, what substances are restricted, which LED device components are most affected, how compliance is verified, and what buyers should ask manufacturers to provide.
What RoHS Actually Restricts
The current RoHS directive — RoHS 3, officially Directive (EU) 2017/2102 amending Directive 2011/65/EU — restricts the following ten substance categories in electrical and electronic equipment:
| Substance | Maximum Concentration (by weight) | RoHS Reference |
|---|---|---|
| Lead (Pb) | 0.1% | RoHS Substance 1 |
| Mercury (Hg) | 0.1% | RoHS Substance 2 |
| Cadmium (Cd) | 0.01% | RoHS Substance 3 |
| Hexavalent Chromium (Cr VI) | 0.1% | RoHS Substance 4 |
| Polybrominated Biphenyls (PBB) | 0.1% | RoHS Substance 5 |
| Polybrominated Diphenyl Ethers (PBDE) | 0.1% | RoHS Substance 6 |
| Bis(2-ethylhexyl) phthalate (DEHP) | 0.1% | RoHS Substance 7 |
| Butyl benzyl phthalate (BBP) | 0.1% | RoHS Substance 8 |
| Dibutyl phthalate (DBP) | 0.1% | RoHS Substance 9 |
| Diisobutyl phthalate (DIBP) | 0.1% | RoHS Substance 10 |
Substances 7–10 were added under RoHS 3 (Directive (EU) 2015/863), which took full effect on July 22, 2019. These four phthalates are primarily found in flexible PVC cables, wire insulation, and some polymer components.
The concentration limits are expressed as maximum concentration by homogeneous material — meaning the 0.1% limit applies to each individual homogeneous material in the product, not to the total weight of the finished product. A cable jacket containing 0.08% lead is compliant. A solder joint containing 0.2% lead is not compliant — even if the lead represents 0.0001% of the total product weight.
Which LED Therapy Device Components Are Most Affected
Solders and Electrical Connections
Traditional tin-lead solder (Sn63Pb37 or Sn60Pb40) is the most common RoHS compliance issue for electronic assemblies. Lead is restricted at 0.1% by homogeneous material — and a solder joint is a homogeneous material.
RoHS-compliant alternatives:
- SAC305 (Tin-Silver-Copper, 96.5% Sn / 3% Ag / 0.5% Cu): The most widely used lead-free solder alloy. Higher melting point (217–220°C) than tin-lead (183°C), which affects reflow profile design.
- SAC387 / SAC405 (lower silver variants): Lower silver content reduces cost with minor differences in mechanical properties.
- Tin-copper (Sn99.3Cu0.7): Lower cost, higher melting point (227°C), used in wave soldering applications.
The silver in SAC305 solder is not a restricted substance — but silver mining and supply chain costs make SAC305 more expensive than tin-lead. This is one reason some low-cost manufacturers resist the transition to RoHS-compliant soldering.
Cable Jackets and Wire Insulation
Flexible PVC cable jackets are one of the most common sources of RoHS failures — specifically for the four phthalate plasticizers (DEHP, BBP, DBP, DIBP) added under RoHS 3.
Phthalates are used to make PVC flexible. A flexible PVC cable jacket that is not specifically formulated as RoHS-compliant almost certainly contains one or more restricted phthalates.
RoHS-compliant alternatives:
- RoHS-compliant PVC: Formulated without restricted phthalates, using alternative plasticizers such as citrates, trimellitates, or bio-based plasticizers
- TPE (Thermoplastic Elastomer) cable jackets: Increasingly common in premium devices; inherently phthalate-free
- Silicone cable: Naturally RoHS-compliant; used in premium applications
Verification: Ask the cable supplier for the RoHS test report and confirm the specific plasticizer used in the formulation.
Housing and Structural Plastics
The device housing — typically ABS, polycarbonate (PC), or ABS+PC blend — is generally RoHS-compliant as a base resin. The issue is in the additives, colorants, flame retardants, and plasticizers used in the formulation.
Common RoHS risks in housing materials:
- Cadmium-based colorants: Cadmium sulfide pigments (cadmium yellow, orange, red) are restricted at 0.01%. Bright yellow or orange plastics that are not specifically RoHS-compliant may contain cadmium pigments.
- Deca-BDE (decabromodiphenyl ether) flame retardants: PBDEs are restricted at 0.1%. Some older flame retardant formulations may contain restricted PBDEs.
- Plasticizers in soft-touch overmolds: Soft-touch rubberized coatings on the device housing may contain restricted phthalates.
LEDs and Optical Components
LED chips themselves — the semiconductor die — are exempt from RoHS substance restrictions under Annex III of the directive (categories for LEDs and semiconductors). However, the LED package — the epoxy lens, the lead frame, the silicone encapsulant — is subject to RoHS restrictions.
Specific concern: Some LED packages use lead-frame materials that contain small amounts of lead as an impurity or alloying element. While most major LED manufacturers have transitioned to RoHS-compliant lead frames, buyers should verify this for budget LED components sourced from secondary suppliers.
Battery Components
Battery cells themselves are generally exempt from RoHS under Annex IV (medical device exemptions) or are addressed under separate battery regulations (EU Battery Directive 2006/66/EC). However, battery holders, battery connectors, and battery compartment plastics may contain restricted substances and are subject to RoHS.
The RoHS Exemption System — Why Some Restricted Substances Are Still Used
RoHS operates on a restriction with exemption model. Some applications of restricted substances are exempted because no viable RoHS-compliant alternative currently exists.
For LED therapy devices, the most relevant exemptions are:
Annex III Exemptions (selected)
- Exemption 7(a): Lead in glass of cathode ray tubes, electronic components, and fluorescent tubes — still relevant for some older display components
- Exemption 8(a): Lead in bearing shells and bushes for some applications
- Exemption 15: Lead in solders for the assembly of electronic circuit boards — partially expired; some exemptions expired July 2021
- Exemption 34: Cadmium in thin-film photovoltaic modules — not typically relevant for LED therapy devices
The Annex III exemption list is regularly reviewed and expires on a schedule. Manufacturers relying on exemptions must monitor the exemption expiry dates and plan for alternatives before the exemption expires.
Annex IV — Medical Device Exemptions: Medical devices have their own exemptions under Annex IV of RoHS, which are generally broader and longer-lived than the Annex III exemptions. LED therapy devices classified as medical devices under EU MDR may qualify for some Annex IV exemptions. However, the trend in EU regulation is toward narrowing exemptions — relying on an expiring exemption is not a long-term compliance strategy.
How RoHS Compliance Is Verified
Step 1: Bill of Materials Review and Substance Declaration
The process begins with a Bill of Materials (BOM) review — compiling the material declarations from every component supplier. This is the most important step and the most time-consuming.
The standard format for supplier substance declarations is the IEC 62474 Declaration Checklist or the IMDS (International Material Data System) for automotive-grade components. For RoHS compliance, each supplier must provide a declaration confirming:
- The homogeneous materials in their component
- The RoHS substance content of each homogeneous material
- Any RoHS exemptions claimed, with justification
The critical point: The declaration comes from the component supplier — not from the LED manufacturer. The LED manufacturer is only as compliant as the weakest link in their supply chain. If a single cable supplier cannot provide a RoHS-compliant substance declaration, the finished device is not RoHS-compliant.
Step 2: X-Ray Fluorescence (XRF) Screening
XRF analysis is a rapid, non-destructive screening method that can detect the presence of RoHS-restricted substances in a sample. XRF instruments are widely available and can provide screening results in minutes.
XRF limitations:
- XRF can detect the presence of restricted substances but cannot always determine whether the concentration is above or below the RoHS limit — particularly for lead at the 0.1% threshold
- XRF cannot reliably detect RoHS Substance 3 (cadmium) at the 0.01% limit in some material matrices
- XRF cannot detect restricted phthalates (DEHP, BBP, DBP, DIBP) — these require laboratory testing by GC-MS (gas chromatography-mass spectrometry)
- XRF is a screening tool, not a definitive compliance test
Best practice: Use XRF screening during incoming quality control (IQC) as a rapid check, and submit critical components (solder, cable, housing) to an accredited laboratory for definitive testing.
Step 3: Laboratory Testing
For definitive RoHS compliance verification, samples are sent to an accredited laboratory (ISO 17025 accredited) for chemical analysis:
| Substance(s) | Test Method | Sample Type |
|---|---|---|
| Lead, Mercury, Cadmium, Chromium VI | IEC 62321 (XRF screening + ICP confirmatory) | Any homogeneous material |
| PBDE, PBB | IEC 62321 (solvent extraction + GC-MS or HPLC) | Polymer materials, cable jackets |
| Phthalates (DEHP, BBP, DBP, DIBP) | IEC 62321 (solvent extraction + GC-MS) | Cable jackets, flexible polymers |
| Hexavalent Chromium (Cr VI) | IEC 62321 (colorimetric or spectrophotometric) | Metallic coatings, pigments |
The laboratory test report is the primary evidence of RoHS compliance. For LED therapy devices sold in the EU, the test report should cover:
- The specific model tested (not just a generic “LED device” designation)
- The specific homogeneous materials tested (solder, cable jacket, housing, battery connector)
- The measured concentration of each restricted substance
- Comparison to the RoHS limit with a pass/fail conclusion
Step 4: CE Marking and Declaration of Conformity
RoHS compliance is incorporated into the CE Declaration of Conformity (DoC) under the Low Voltage Directive (LVD, 2014/35/EU) or the Radio Equipment Directive (RED, 2014/53/EU) for products with wireless functionality. The CE DoC must list the applicable directives — and RoHS is included by reference.
The CE DoC is signed by the manufacturer’s authorized representative and confirms that the product meets all applicable EU directives, including RoHS. The DoC is a legal document — it carries legal liability.
Common RoHS Compliance Mistakes
Mistake 1: Assuming the LED manufacturer handles RoHS compliance. The LED manufacturer controls the assembly-level RoHS compliance — the solder, the conformal coating, and the PCB. But they depend on their component suppliers for material-level compliance. If a connector supplier cannot provide a substance declaration, the connector — and therefore the device — is non-compliant. RoHS compliance is only as strong as the weakest supplier.
Mistake 2: Accepting supplier declarations at face value without verification. A supplier declaration is a legal statement — but it is only as accurate as the supplier’s knowledge and testing. The manufacturer’s own verification (XRF screening, laboratory testing) is the only reliable evidence of compliance.
Mistake 3: Not testing the cable jacket for phthalates. This is the most commonly missed test for RoHS 3 compliance. Phthalates (DEHP, BBP, DBP, DIBP) are not detectable by XRF — they require GC-MS testing. Many compliant-looking cable jackets fail RoHS testing specifically for phthalate content.
Mistake 4: Relying on expired or expiring exemptions. Exemption expiry dates are published and tracked. If your product relies on an exemption that expired, you have a compliance gap — not a compliance status. Plan the alternative material transition 12–18 months before the exemption expiry.
Mistake 5: Not maintaining RoHS compliance records for 10 years. RoHS compliance documentation — substance declarations, test reports, DoC — must be maintained for a minimum of 10 years after the product is last placed on the market. This is a legal requirement, not a recommendation.
RoHS Compliance — Common Questions
Q1: Our LED therapy mask is certified to other markets (FDA, CE). Does that mean it is RoHS compliant?
Not necessarily. FDA clearance and CE marking address electrical safety, biocompatibility, and electromagnetic compatibility. RoHS addresses chemical substance restrictions in materials — this is a separate compliance domain. A device can have full FDA and CE certification and still contain restricted substances above RoHS limits. You must verify RoHS compliance separately — specifically requesting the RoHS test reports and substance declarations from the manufacturer.
Q2: We are buying from a manufacturer who says their product is “RoHS compliant” but cannot provide a test report. What should we do?
This is a red flag. “RoHS compliant” without supporting documentation is a marketing statement — not a compliance declaration. A legitimate compliance claim is backed by: (1) Bill of Materials with substance declarations from each component supplier (IEC 62474 or equivalent format), (2) XRF screening results or laboratory test reports from an accredited laboratory covering the specific materials in the device, and (3) the RoHS substance declarations incorporated into the CE DoC. Ask for these documents before placing an order. If the manufacturer cannot provide them, do not assume compliance.
Q3: We are designing a custom OEM product with a flexible PVC cable. The cable supplier says the cable is “standard.” Is this RoHS compliant?
“Standard” PVC cable is almost certainly not RoHS-compliant under RoHS 3 (EU) — standard flexible PVC almost always contains restricted phthalates as plasticizers. You need: (1) a RoHS-compliant PVC cable formulation — explicitly specified as RoHS-compliant — or (2) an alternative cable material such as TPE or silicone. Ask the cable supplier for: the specific formulation, the plasticizer used (must be phthalate-free), and a RoHS substance declaration confirming the four phthalates are not present. Then verify with a laboratory GC-MS test on the actual cable jacket material.
This article is written from the perspective of an LED therapy OEM manufacturer that maintains RoHS compliance documentation for all products sold in the EU market. Substance restrictions and exemptions reflect current RoHS Directive (EU) 2011/65/EU as amended by (EU) 2017/2102 and (EU) 2015/863. RoHS requirements are subject to periodic review and amendment — always verify current requirements with a qualified regulatory specialist for your specific product and target market.