2.5. Determination of formaldehyde emission of particleboard
Three samples (20 mm × 20 mm × 18 mm) were randomly taken from each type of particleboard for formaldehyde emission (FE) determination using the perforator method based on EN 120-1 standard [15]. The perforator test involves reflux in boiling toluene with approximately 110 g of small cube samples. The reflux speed of the system was adjusted to 30 ml/min, and extraction was conducted for 2 h. The extracted formaldehyde was collected in water, which was then added with 50 ml of iodine solution and 20 ml of sodium hydroxide in a dark room for 15 min. A 10 ml mixture of sulfuric acid and sodium thiosulphate solution was applied to the mixture until its color changes from light brown to light yellow.