XRF for Detecting Cadmium in Products
Cadmium has the strictest concentration limit in the RoHS restricted substance list. 0.01% by weight, ten times lower than the limits for lead, mercury, and chromium.
That tighter threshold reflects cadmium's higher toxicity and its persistence in biological systems.
Cadmium appears in electronics through several pathways-
- Cadmium-based pigments (used in certain plastic colorants)
- Cadmium stabilizers (historically been used in PVC formulations)
- Cadmium plating (legacy components, certain specialty fasteners)
- Nickel-cadmium battery chemistry
At 0.01%, cadmium detection requires an XRF instrument with sufficient sensitivity to reliably distinguish compliant from non-compliant material near the threshold. Modern handheld XRF analyzers equipped with high-performance silicon drift detectors achieve the detection limits needed for cadmium screening at RoHS concentrations with measurement times in the range of 30 to 60 seconds for reliable results near the limit.
Plastic components are a particularly important cadmium screening target. Brightly colored plastic housings, cable insulation, and decorative trim pieces sourced from suppliers with inconsistent quality controls represent meaningful cadmium risk. XRF measurement of plastic components requires attention to sample geometry — flat, homogeneous surfaces give more reliable readings than curved or textured surfaces where beam geometry affects the result.
For cadmium screening at RoHS thresholds, the combination of XRF for initial screening and laboratory ICP analysis for confirmation of samples near the 0.01% limit is the right workflow. XRF catches the obvious non-conformances and narrows the confirmation workload to the samples where quantitative precision at the boundary actually matters.
Cadmium compliance is not a surface-level check. It requires understanding which material types carry risk and applying the right testing method to each one.
Screen plastics, platings, and components for cadmium before they create a compliance failure.
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There are a lot of ways to save money and time with XRF analysis, especially when it comes to RoHS and other legal compliances. Learn more about the uses and benefits of XRF analysis for your business from an XRF professional.