The direct answer
RoHS testing follows the EN/IEC 62321 standard series, with each substance group measured by its own method: metals and chromium VI by EN 62321-4/5/7-2 with ICP-OES and UV-Vis, PBBs/PBDEs by EN 62321-6 with GC-MS, and phthalates by EN 62321-8 with GC-MS. N.D. in a RoHS report means the substance is below the method's detection limit - stated as 2 mg/kg for metals, 5 mg/kg for the flame-retardant congeners and 50 mg/kg for phthalates in our Model 1338 report. Without the method and the limit, "passed RoHS" is a summary with no evidence behind it.
The standard map
|
Substance group |
EN/IEC method |
Instrument |
MDL in our report |
|
Lead, cadmium |
EN 62321-5 / 62321-4 |
ICP-OES |
2 mg/kg |
|
Mercury |
EN 62321-4 |
ICP-OES |
2 mg/kg |
|
Hexavalent chromium |
EN 62321-7-2 |
UV-Vis (after extraction) |
2 mg/kg |
|
PBBs and PBDEs |
EN 62321-6 |
GC-MS |
5 mg/kg per congener |
|
Phthalates |
EN 62321-8 |
GC-MS |
50 mg/kg |
The EN 62321 series is equivalent to IEC 62321 - the report says so explicitly, and the two are used interchangeably in RoHS testing.
How each group is measured
Metals (lead, cadmium, mercury)
The sample is digested with acid, using microwave or hotplate digestion, then analyzed on the ICP-OES - the same instrument family used in lead testing elsewhere in this certification series. The measured concentration is compared to the 1000 mg/kg (or 100 mg/kg for cadmium) limit.
Hexavalent chromium
Cr VI is extracted from the material, and a color-forming reagent (1,5-diphenylcarbazide) is added - a red color indicates presence. The result is confirmed with UV-Vis spectroscopy. Cr VI needs its own method because it is about chemical state, not total chromium.
PBBs and PBDEs
The sample is extracted with solvent, concentrated and run through GC-MS. The report lists every congener from mono- to deca-bromobiphenyl and diphenyl ether - twenty congeners, each screened at a 5 mg/kg detection limit.
Phthalates
The same solvent-extraction and GC-MS approach measures DEHP, BBP, DBP and DIBP at a 50 mg/kg detection limit - twenty times below the 1000 mg/kg limit.
Factory data: The detection limits in our report are worth reading, because they are the difference between evidence and decoration. A metal result of N.D. at MDL 2 means the material is at least 500 times below the lead limit and 50 times below the cadmium limit. A phthalate result of N.D. at MDL 50 is still twenty times below the limit. Those margins are the real news.
What N.D. means, precisely
N.D. - not detected - means the substance is below the method detection limit. It does not mean "zero"; it means "below the floor the method can reliably report." The floor matters:
- Metals at MDL 2: at least 500x below the 1000 limit, 50x below the 100 cadmium limit.
- PBB/PBDE at MDL 5: 200x below the summed limit.
- Phthalates at MDL 50: 20x below the limit.
A report that states N.D. without an MDL is hiding its own standards.
FAQ
What standard is used for RoHS testing?
The EN/IEC 62321 series: 62321-4 and -5 for metals, 62321-7-2 for hexavalent chromium, 62321-6 for PBBs/PBDEs, and 62321-8 for phthalates.
Why does hexavalent chromium need its own method?
Because it is about the chemical state of chromium, not total chromium. The extraction and color-development method (EN 62321-7-2) distinguishes Cr VI from other forms.
What does N.D. mean in a RoHS report?
Not detected - the substance is below the method detection limit shown in the report. It is the strongest result the method can produce, and it only means something with the MDL stated.
What is the detection limit in our report?
2 mg/kg for the metals and Cr VI, 5 mg/kg for each PBB/PBDE congener, and 50 mg/kg for the phthalates - each far below its regulatory limit.
Can one test cover all ten substances?
No single instrument can. The ten substances span metals, flame retardants and plasticizers, which is why the EN 62321 series uses multiple methods and instruments.
How do I know the methods are current?
Check the standard versions and amendment years on the report (ours cites EN 62321-4:2014+A1:2017, -5:2014, -6:2015, -7-2:2017, -8:2017). Dated standards are part of the evidence.
About this report
The method analysis in this article comes from report No. S250827030001-1 for our Model 1338 - the EN 62321 series, five methods, three instrument families, and detection limits far below every regulatory limit. We share the method and result pages with buyers so the scope can be verified line by line. Ask for them at clkbusiness@clkluggage.com or WhatsApp +86-18879628221.