Overview
ISO 12460-4:2016 specifies the desiccator method for measuring formaldehyde release from wood-based panels. It applies to particleboard, fibreboard, plywood, oriented strand board (OSB) and wooden laminated flooring. The method determines the quantity of formaldehyde emitted from prepared test pieces placed in a controlled desiccator atmosphere for 24 hours and quantified photometrically using the acetylacetone (Hantzsch) reaction.
Key topics and requirements
- Scope and materials: Particleboard, fibreboard, plywood, OSB and laminated flooring.
- Test principle: Emitted formaldehyde is absorbed in a defined volume of water in a glass dish and quantified by the acetylacetone photometric method (Hantzsch reaction) with measurement at 412 nm.
- Test piece sampling & size: Sampling per ISO 16999; individual piece dimensions (150 ±1 mm × 50 ±1 mm); total surface area of test pieces should be approximately 1 800 cm².
- Conditioning: Condition specimens for 7 days (or to constant mass) at (20 ±2) °C and (65 ±5) % RH; constant mass = two successive weighings 24 h apart differing by ≤0.1 %.
- Desiccator and apparatus: Use glass desiccators (11 ±2 L), stainless-steel wire mesh and holder, glass crystallizing dish (300 ml; inside diameter ~115 mm), temperature probe (±0.1 °C), spectrophotometer (412 nm). For low-emitting boards, use cells with pathlength ≥50 mm or fluorometric detection.
- Test conditions: Temperature inside desiccator maintained at (20 ±0.5) °C; test duration 24 h ±10 min.
- Quality controls:
- Run tests in duplicate; if results differ by >20 % of the mean, perform a third test.
- Monitor background formaldehyde - maximum accepted background is 0.05 mg/L; during conditioning background must be less than expected emission level.
- Sample handling: collect 300 ml water, store 0–5 °C up to 30 h if not analysed immediately.
- Analysis & calibration: Photometric determination using acetylacetone-ammonium acetate reagents; calibration with formaldehyde standards and calculation of concentration in the desiccator dish.
Applications and users
ISO 12460-4:2016 is used for:
- Laboratory testing and quality control of wood-based panel manufacture
- Product compliance and certification for formaldehyde emission limits
- Material selection and R&D to develop lower-emitting panels and flooring
- Regulatory and procurement specifications for indoor air quality-sensitive projects
Typical users: testing laboratories, manufacturers of wood-based panels and flooring, building material specifiers, regulatory bodies, and indoor air quality consultants.
Related standards
Keywords: ISO 12460-4, desiccator method, formaldehyde release, wood-based panels, formaldehyde emission testing, particleboard, plywood, OSB, laminated flooring, acetylacetone method, Hantzsch reaction.