ISO 12460-4:2016

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

• ISO 12460-1 - 1 m³ chamber method
• ISO 12460-3 - Gas analysis method
• ISO 12460-5 - Extraction (perforator) method
• ISO 16999 - Sampling and cutting of test pieces

Keywords: ISO 12460-4, desiccator method, formaldehyde release, wood-based panels, formaldehyde emission testing, particleboard, plywood, OSB, laminated flooring, acetylacetone method, Hantzsch reaction.