Recycled Resources Testing: Comprehensive Analysis of Secondary Materials for Quality, Safety, and R

Recycled resources testing provides the analytical foundation for trading, processing, and certifying secondary materials such as scrap metals, recycled plastics, waste paper, electronic scrap, and recovered fuels. Through standardized chemical, physical, and environmental analysis, accredited third-party laboratories verify material composition, purity, and regulatory compliance, enabling safe material recovery and supporting global circular economy initiatives. This article outlines the sample types, key testing items, analytical methods, standards, and practical applications of recycled resources testing.

Technical Overview

Recycled resources, also referred to as secondary resources, are materials recovered from waste streams and reintroduced into production cycles, including ferrous and non-ferrous scrap metals, recycled plastics, paper and board for recycling, waste electrical and electronic equipment (WEEE), end-of-life vehicles, scrap tires, waste textiles, spent batteries, glass cullet, and solid recovered fuels. Recycled resources testing is the systematic technical evaluation of these materials to determine their chemical composition, grade classification, purity, physical properties, calorific value, and the presence of restricted or hazardous substances.

The discipline has become increasingly critical as global supply chains adopt circular economy principles and regulators tighten controls on cross-border movements of waste. International frameworks such as the Basel Convention, the EU RoHS Directive 2011/65/EU, the REACH Regulation (EC) No 1907/2006, and the Stockholm Convention on Persistent Organic Pollutants all impose strict requirements on secondary materials. At the same time, recycled content claims made under standards such as ISO 14021 and validated through schemes like UL 2809 require reliable, traceable analytical data. Testing is typically performed by accredited third-party laboratories operating in conformity with ISO/IEC 17025, ensuring that results are technically valid, legally defensible, and mutually recognized across markets.

Testing Samples

Ferrous and Non-Ferrous Metal Scrap

This category covers steel and cast iron scrap, stainless steel turnings, copper, aluminum, zinc, lead, and nickel-based alloys, as well as chopped wire and cable. Testing focuses on alloy composition, grade conformity, valuable metal content, and tramp or deleterious elements such as copper, tin, and arsenic in ferrous grades. Incoming loads are also screened for radioactive contamination and sealed containers or explosive ordnance hazards.

Recycled Plastics and Regranulates

Samples include PET flake from bottles, HDPE, LDPE, and PP regranulates, ABS, PS, PA, and PC recyclates, and mixed plastic streams. Characterization follows the EN 15342 to EN 15347 series for plastics recyclates and the GB/T 40006 series for recycled plastics, covering polymer identity, melt flow rate, density, color, contamination level, and mechanical performance.

Paper and Board for Recycling

Grades such as old corrugated containers (OCC), old newspapers, mixed papers, and deinked pulp are assessed against EN 643, the European list of standard grades of paper and board for recycling. Key parameters include moisture content, proportion of unusable materials, prohibited materials, and ash content, which directly affect commercial settlement between buyers and sellers.

Waste Electrical and Electronic Equipment (WEEE)

Samples range from whole devices and populated printed circuit boards to shredded fractions and plastics recovered from electronics. Because WEEE plastics frequently contain legacy brominated flame retardants, testing emphasizes RoHS restricted substances under IEC 62321 methods, persistent organic pollutants, and heavy metals.

End-of-Life Vehicles and Shredder Residues

Vehicle hulks, engine blocks, and automotive shredder residues are analyzed for metal yield, oils and fluids, heavy metals such as lead, cadmium, and mercury, and recyclability metrics. Calculation of recyclability and recoverability rates can be performed in accordance with ISO 22628 for road vehicles.

Scrap Tires and Rubber Recyclates

Whole tires, tire-derived fuel, crumb rubber, and reclaimed rubber are tested for proximate composition, calorific value, polycyclic aromatic hydrocarbons (PAHs), heavy metals such as zinc and lead, and elastomer identity to determine suitability for playground surfaces, sports fields, molded goods, or energy recovery.

End-of-Life Batteries and Black Mass

Lithium-ion, nickel-metal hydride, and lead-acid battery wastes, along with the shredded black mass generated during recycling, are assayed for valuable metals including lithium, nickel, cobalt, manganese, and copper, as well as impurities and hazardous constituents that affect hydrometallurgical recovery efficiency and classification.

Waste Textiles, Glass Cullet, and Solid Recovered Fuels

Textile recyclates are identified by fiber composition and screened for azo dyes and formaldehyde; glass cullet is graded by color, ceramic contamination, and moisture; and refuse-derived or solid recovered fuels are characterized under the EN 15400 series for calorific value, chlorine, sulfur, mercury, and biomass content to confirm compliance with co-incineration limits.

Testing Items

Testing programs for recycled resources are structured around four principal groups of parameters, selected according to material type, intended application, and the regulatory regime of the destination market.

• Chemical composition and grade classification, including major and trace element analysis, alloy identification, purity, and yield of valuable metals
• Heavy metals, including lead, cadmium, mercury, arsenic, hexavalent chromium, antimony, thallium, beryllium, and nickel
• Restricted substances under RoHS Directive 2011/65/EU and (EU) 2015/863, covering lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), and the four regulated phthalates
• REACH substances of very high concern (SVHC), Annex XVII restricted substances, and persistent organic pollutants such as PCBs, short-chain chlorinated paraffins (SCCPs), HBCD, PFAS, and PBDEs under the Stockholm Convention
• Total halogen content (chlorine and bromine) and sulfur, which govern corrosion and emission behavior in thermal recovery and metallurgical applications
• Proximate and fuel properties, including moisture, ash, volatile matter, gross and net calorific value, and particle size distribution
• Polymer-specific properties such as melt flow rate per ISO 1133, density per ISO 1183, colorimetric values, and contamination counts
• Mechanical properties of recycled resins and compounds, including tensile strength per ISO 527 and impact resistance per ISO 179
• Foreign matter and impurity content, including outthrows and prohibited materials in paper grades per EN 643
• Radioactivity screening by dose-rate survey and gamma spectrometry to exclude orphan radioactive sources in scrap shipments

For materials destined for food contact, toys, or other sensitive applications, additional migration testing, microbiological examination, and odor assessment may be incorporated into the testing plan.

Testing Methods

Reliable results depend on representative sampling and rigorous sample preparation, followed by instrument-based analysis calibrated against certified reference materials. Laboratories combine rapid screening techniques with confirmatory quantitative methods to balance turnaround time and data quality.

• X-ray fluorescence spectrometry (XRF) for rapid non-destructive elemental screening, applied in the field and laboratory per the IEC 62321-3-1 screening procedure for electrotechnical products
• Optical emission spectrometry (OES) for alloy sorting and full metal grade verification in scrap metals
• Inductively coupled plasma optical emission spectrometry (ICP-OES) and ICP mass spectrometry (ICP-MS) after microwave acid digestion for precise quantification of metals and heavy elements
• Combustion ion chromatography (CIC) and oxygen bomb combustion for total chlorine, bromine, fluorine, and sulfur
• Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for phthalates, brominated flame retardants, PAHs, PCBs, SCCPs, and PFAS
• UV-Visible spectrophotometric and colorimetric procedures for hexavalent chromium per the IEC 62321-7 series
• Bomb calorimetry per ISO 1928 and the EN 15400 series for gross and net calorific value of solid recovered fuels and tire-derived fuels
• Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy for polymer identification and contaminant detection
• Differential scanning calorimetry (DSC) per ISO 11357 for melting and crystallization behavior, and thermogravimetric analysis (TGA) per ASTM E1131 for compositional analysis
• Ash determination in plastics per ASTM D5630 and in solid fuels per ISO 1171
• Manual sorting and gravimetric fractionation protocols for paper grades per EN 643 and for waste-derived fuels
• Gamma spectrometry and portable dose-rate instruments for radionuclide identification and radiation clearance of scrap metal consignments

Applications

Recycled resources testing delivers measurable value across the entire secondary materials value chain, from collection and trading to processing, product manufacturing, and regulatory reporting.

• Trade compliance and customs clearance, supporting correct classification of shipments as usable secondary raw materials rather than controlled waste under Basel Convention procedures
• Commercial settlement and grading, providing objective moisture, purity, and yield data for contracts between scrap traders, recyclers, and smelters
• Hazardous waste identification and exclusion testing in line with the GB 5085 series for corrosion, toxicity, ignitability, reactivity, and infectious characteristics
• Recycled content verification for environmental labels and marketing claims under ISO 14021 and validation schemes such as UL 2809
• Incoming quality control and supplier qualification at recycling plants and manufacturing sites using recycled feedstocks
• Product development support, confirming that recyclates meet mechanical, thermal, and compositional specifications before substituting virgin materials
• Life cycle assessment and carbon footprint accounting per ISO 14040 and ISO 14044, underpinning ESG disclosures and corporate decarbonization strategies
• Process optimization, using analytical data on contamination and losses to improve sorting, washing, and recovery efficiency

FAQ

What is recycled resources testing?

Recycled resources testing is the laboratory and field evaluation of secondary materials, such as scrap metals, recycled plastics, waste paper, WEEE, tires, and recovered fuels, to determine their composition, quality, purity, and compliance with safety and environmental regulations before they are traded, processed, or used in new products.

Why is restricted substance testing important for recyclates?

Legacy additives such as brominated flame retardants, phthalates, heavy metals, and persistent organic pollutants frequently remain in waste streams and can be carried into recycled products. Testing against RoHS Directive 2011/65/EU, REACH, and Stockholm Convention requirements prevents non-compliant recyclates from entering electronics, toys, food contact materials, and other regulated applications, and protects human health and the environment.

Which standards are most commonly applied?

Frequently referenced frameworks include the EN 15342 to EN 15347 series for plastics recyclates, EN 643 for paper grades, IEC 62321 for RoHS substance determination, ISO 1928 and the EN 15400 series for calorific value, ISO 1133 and ISO 11357 for polymer properties, ISO 14021 for recycled content claims, UL 2809 for recycled content validation, and the GB 5085 series for hazardous waste identification.

How are samples collected and how much material is required?

Because recycled materials are highly heterogeneous, representative sampling through incremental collection, coning and quartering, or riffling is essential. Typical laboratory submissions range from several hundred grams for homogeneous regranulates to tens of kilograms for heterogeneous scrap, tire, or fuel samples, with larger composite samples taken at loading points for commercial disputes.

How should a testing laboratory be selected?

Buyers and recyclers should choose accredited third-party laboratories holding ISO/IEC 17025 accreditation for the specific test methods required, with demonstrated experience in the relevant material category, documented traceability of standards and reference materials, and the capability to support result interpretation for customs, certification, and contractual purposes.