Eco-friendly Decorative Board Testing

Environmentally friendly decoration board testing is conducted in accordance with relevant standards and industry specifications. Scientific testing and analysis are performed on formaldehyde emission, total volatile organic compounds, benzene series emission, heavy metal content, and specific activity of radionuclides, objectively assessing the product quality grade. A detailed test report is issued within 7-10 working days, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Formaldehyde emission: This is a core indicator for the testing of environmentally friendly boards. Residual formaldehyde in the board will be released over a long period and is harmful to human health. Testing is mainly based on the national standard GB 18580, and the formaldehyde release concentration per unit time, per unit area or per unit mass of the board is determined by the chamber method, the desiccator method or the gas analysis method, serving as the key basis for judging its environmental grade.

Total volatile organic compounds (TVOC) emission: TVOC includes benzene, toluene, xylene, ethylbenzene and other volatile organic compounds. Its testing usually adopts chamber sampling combined with thermal desorption/gas chromatography-mass spectrometry. By simulating the actual service environment, the total TVOC release concentration of the board is determined to evaluate its overall pollution level to indoor air.

Benzene series emission: Benzene, toluene, xylene and other benzene series are common VOC components with toxicity. During testing, the sample is placed in a climate chamber and the released gas is collected with adsorbents such as Tenax tubes, and then separated and quantitatively analyzed by thermal desorption-gas chromatography to determine whether the content exceeds the safety limits.

Heavy metal content: Mainly detects the migratable heavy metal elements in the surface coating or substrate of the board, such as lead, cadmium, chromium and mercury. In accordance with the GB 18584 standard, atomic absorption spectrometry or inductively coupled plasma mass spectrometry is used to determine the sample after acid solution extraction, so as to prevent heavy metals from harming the human body through contact or air migration.

Specific activity of radionuclides: Targets industrial waste residue or natural stone components that may be used in wood-based panels. In accordance with the GB 6566 standard, a low-background multi-channel gamma spectrometer is used to measure the specific activity of radium-226, thorium-232 and potassium-40 in the board, and the internal exposure index and external exposure index are calculated to ensure that the radioactivity level is within the safe range.

Testing Scope

Plywood: Made by bonding multiple layers of wood veneer or thin wood. The formaldehyde and TVOC release problems caused by its adhesives need to be emphasized. Different adhesive types (such as urea-formaldehyde resin, phenolic resin and MDI adhesive) have a huge impact on environmental performance, so the testing needs to cover products of different thicknesses and numbers of layers.

Fiberboard (MDF): Made of wood fiber or other plant fiber as raw material with the addition of adhesives. Its internal structure is uniform, and pollutant release is relatively stable but persistent. Testing needs to pay attention to the relationship between its density grade (high, medium and low) and the pollutant release rate, as well as the influence of surface edge-sealing treatment on test results.

Particleboard: Made by hot-pressing wood or non-wood plant particles with adhesives. Because of the large amount of particles and adhesive used, it is a "heavy disaster area" of formaldehyde emission. During testing, attention should be paid to the representativeness of sampling, considering the influence of different particle forms and adhesive application uniformity on the results.

Blockboard: Uses spliced solid wood strips or a grid as the core board, covered on both faces with veneer or plywood. Testing focuses on the adhesives used at the splicing points of the core strips and for bonding the surface boards. Due to its special structure, sampling and testing need to cover both the core material and the surface layer material.

Decorative veneered wood-based panels and decorative boards: Refers to products in which the surface of the substrate (such as particleboard and MDF) is overlaid with natural wood veneer, decorative paper, resin-impregnated paper and other surface materials. Testing needs to evaluate the hazardous substance content of the surface material itself, as well as the inhibiting effect of the surfacing process (whether it is sealed) on the release of hazardous substances from the substrate.

Glulam and solid wood composite boards: Made by splicing and gluing solid wood strips or veneers. Although they contain a large amount of solid wood, the glue lines used for splicing are the main source of pollutants. Testing needs to focus on the environmental performance of the glue lines and the slight VOC differences that different wood species may bring.

Testing Methods

Chamber method (1 m³ or large chamber method): A board sample of specified area is placed in a climate chamber in which temperature, humidity, air exchange rate and air flow velocity are all strictly controlled. Air is drawn out of the chamber and collected through absorption bottles or adsorption tubes, and the pollutant concentration is determined by chemical analysis. This method is closest to the actual service environment of the board, gives accurate data, and is the arbitration method.

Desiccator method: The sample is placed in a desiccator with distilled water at the bottom and left at a constant temperature for a specified time. The formaldehyde is absorbed by the water, and then the formaldehyde concentration in the absorption solution is determined by the acetylacetone spectrophotometric method. This method requires simple equipment and is convenient to operate. It is a common method for in-house control of domestic enterprises and market supervision, and is suitable for rapid screening of formaldehyde emission.

Perforation extraction method: After the sample is crushed, the soluble formaldehyde in the board is extracted by heating and refluxing in toluene solvent in a perforation extraction apparatus, and then determined by titration or spectrophotometry. This method measures the "potential" total formaldehyde content inside the board rather than the emission, and is commonly used for quality control of raw materials and production processes.

Gas chromatography-mass spectrometry (GC-MS): This is the core method for analyzing complex organic compounds such as TVOC and benzene series. The gas collected from the climate chamber is enriched by adsorption tubes and then thermally desorbed before entering the GC-MS system. The chromatographic column separates each component, and the mass spectrometer performs qualitative (by comparison with standard spectral libraries) and quantitative analysis, with high sensitivity and precise results.

Spectrophotometric method: Mainly used for quantitative analysis of formaldehyde. For example, in the acetylacetone method, formaldehyde reacts with acetylacetone in an acetic acid-ammonium acetate buffer solution to form a stable yellow compound, which is measured colorimetrically at a wavelength of 412 nm. In the phenol reagent method, formaldehyde reacts with the phenol reagent to form a hydrazone, which is oxidized by iron ions under acidic conditions into a blue-green compound for determination.

Atomic absorption spectrometry (AAS): Used for heavy metal content testing. The sample is digested into solution and dissociated into ground-state atoms at high temperature in the atomizer. The characteristic spectral line emitted by the hollow cathode lamp of a specific element is absorbed by the atomic vapor, and the content of lead, cadmium, chromium and other elements is quantitatively analyzed by measuring the absorbance and comparing with the standard curve.

Testing Standards

Domestic Standards:

1. GB 18580-2025, Indoor decorating and refurbishing materials — Limit of formaldehyde emission of wood-based panels and finishing products

2. GB 6566, Limits of radionuclides in building materials

3. GB/T 17657-2022, Test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels

4. GB/T 1931-2009, Method for determination of moisture content of wood

5. GB/T 1936.1-2009, Method of testing in bending strength of wood

International Standards:

1. ISO 12460-1, Determination of formaldehyde emission of wood-based panels — Part 1: 1 m³ chamber method

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Environmental test chamber (climate chamber): Core equipment used to simulate the indoor environment. The chamber body is usually made of inert materials (such as stainless steel and glass) and is equipped with a precise temperature and humidity control system, an air purification system, an air circulation and exchange system and sampling ports. Its inner wall has low adsorption, and the background concentration value must be strictly controlled to ensure accurate and reliable test data.

Gas chromatography-mass spectrometry (GC-MS): Composed of a gas chromatography unit and a mass spectrometry detector. The chromatography unit is responsible for separating complex organic compounds; the mass spectrometry detector ionizes the separated molecules, separates and detects them by mass-to-charge ratio, provides a "fingerprint spectrum" for qualitative analysis, and performs quantification through ion current intensity. It is the "gold standard" instrument for VOC testing.

Thermal desorber: Key equipment for VOC sample pretreatment. It is used to perform two-stage thermal desorption on the adsorption tubes that have collected pollutants. The first-stage desorption desorbs the target compounds from the adsorption tube and focuses them in a cold trap; the second stage rapidly heats the cold trap to inject the highly concentrated target compounds into the gas chromatograph in a narrow band, greatly improving detection sensitivity and resolution.

UV-Vis spectrophotometer: Used for quantitative analysis of specific compounds such as formaldehyde. Its principle is the selective absorption of UV-Vis light by substances. The instrument provides a light source at a specific wavelength, and by measuring the absorbance of the sample solution, the concentration of the analyte is calculated according to the Lambert-Beer law. It is simple to operate and low in cost.

Atomic absorption spectrometer (AAS): The main equipment for heavy metal testing. It is mainly composed of a light source (hollow cathode lamp), an atomization system (flame or graphite furnace), a spectroscopic system and a detection system. The graphite furnace atomizer has extremely high sensitivity and can detect trace heavy metals at the ppb level. The equipment needs to be regularly calibrated with standard solutions to ensure data accuracy.

Low-background multi-channel gamma spectrometer: Used for radioactivity testing. The core component is a high-purity germanium detector that operates under liquid nitrogen cooling and has extremely high energy resolution. It can accurately measure and distinguish the energy and intensity of gamma rays released by different radionuclides in the sample, and calculate the specific activity through professional software. The instrument needs to be placed in a lead room to reduce background interference such as cosmic rays.