Harmful Substances Testing: Methods, Regulations, and Testing Process

　　Harmful substances testing helps manufacturers, importers, and brand owners verify whether materials, components, and finished products contain restricted or potentially hazardous chemicals. It is widely used for regulatory compliance, supply chain risk control, product safety assessment, and failure investigation.

　　What Are Harmful Substances?

　　Harmful substances may come from raw materials, additives, coatings, inks, adhesives, plastics, metals, electronic components, or packaging materials. Common categories include:

　　Heavy metals: Lead (Pb), Cadmium (Cd), Mercury (Hg), Hexavalent Chromium (Cr(VI))

　　Brominated flame retardants: PBBs, PBDEs

　　Phthalates: DEHP, BBP, DBP, DIBP

　　Polycyclic aromatic hydrocarbons (PAHs)

　　Volatile organic compounds (VOCs)

　　Formaldehyde

　　Azo dyes

　　Per- and polyfluoroalkyl substances (PFAS)

　　Organotin compounds

　　Short-chain chlorinated paraffins (SCCPs)

　　Nickel release

　　Halogen compounds

　　Many of these substances are restricted under international regulations such as EU RoHS, EU REACH, China RoHS, California Proposition 65, and various toy, textile, packaging, and food-contact material standards.

　　Common Testing Regulations and Programs

　　Harmful substances testing is usually aligned with the target market and product type. Typical programs include:

　　EU RoHS: Restricts ten substances in electrical and electronic equipment, including heavy metals, brominated flame retardants, and certain phthalates.

　　EU REACH: Covers SVHC screening, Annex XVII restricted substances, and SCIP notification requirements.

　　China RoHS: Focuses on hazardous substance restrictions in electrical and electronic products.

　　California Proposition 65: Requires warning labels for products containing listed chemicals.

　　Toy and consumer product testing: May include heavy metals, phthalates, PAHs, formaldehyde, and azo dyes.

　　Packaging and food-contact material testing: Evaluates potential chemical migration and restricted substances.

　　Key Testing Methods

　　Different harmful substances require different analytical methods. The choice of method depends on the target substance, material matrix, required detection limit, and applicable standard.

　　1. XRF Screening

　　X-ray Fluorescence (XRF) is commonly used for rapid, non-destructive screening of heavy metals such as lead, cadmium, mercury, chromium, and bromine. It is especially useful for incoming material inspection and supply chain risk screening. However, XRF results are usually considered preliminary, and positive findings often need confirmation by laboratory methods.

　　2. ICP-OES / ICP-MS

　　Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are used for accurate quantitative analysis of heavy metals. These methods are suitable for detecting lead, cadmium, mercury, chromium, and other elements at ppm or even ppb levels.

　　3. GC-MS

　　Gas Chromatography-Mass Spectrometry (GC-MS) is widely used for organic harmful substances, such as phthalates, polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), PAHs, and certain VOCs. It provides strong qualitative and quantitative capability for complex organic matrices.

　　4. LC-MS / HPLC

　　Liquid Chromatography-Mass Spectrometry (LC-MS) and High-Performance Liquid Chromatography (HPLC) are suitable for substances that are not easily volatilized or thermally unstable, such as certain phthalates, PFAS, dyes, and other organic additives.

　　5. UV-Vis Spectrophotometry

　　UV-Visible spectrophotometry is often applied to hexavalent chromium testing after chemical extraction. It is a classical method for confirming Cr(VI) in metals, coatings, and polymers.

　　6. Ion Chromatography

　　Ion Chromatography (IC) can be used to detect halogen ions and certain ionic contaminants, supporting halogen screening and material compliance evaluation.

　　7. FTIR and Other Supporting Techniques

　　FTIR, thermal analysis, and microscopic techniques may be used together with chemical testing to identify unknown additives, polymer types, coatings, or contamination sources.

　　Typical Testing Workflow

　　A reliable harmful substances test usually follows these steps:

　　Requirement confirmation

　　Confirm the target market, applicable regulation, product type, and test scope.

　　Sample preparation

　　Products are disassembled into homogeneous materials when necessary. Representative samples are cut, crushed, or extracted according to the test method.

　　Screening or quantitative analysis

　　XRF may be used for initial screening, while ICP-OES, ICP-MS, GC-MS, LC-MS, or UV-Vis is used for precise quantification.

　　Data review and reporting

　　Results are compared with the required limits, and a test report is issued. If a substance exceeds the limit, improvement suggestions can be provided.