Formaldehyde is a simple naturally occurring chemical consisting of hydrogen, oxygen and carbon. Present in some form in common everyday products, formaldehyde does not accumulate in the human body or environment as it is a volatile organic compound that breaks down rapidly. Many of the items found in a typical home such as vinyl, wallpaper, mirrors, textiles, timber, dishwashing liquid and even toothpaste contain a minimal quantity of formaldehyde.
Commonly referred to as WBP (Water & Boil Proof) or A Bond when used as an adhesive in plywood, phenol formaldehyde provides the structural and moisture durability required in structural, exterior and marine grades of plywood. It is easily identified by the black line between the layers of ply. The formaldehyde emissions in these plywood products when bonded with phenol formaldehyde are deemed as very low and exempt from formaldehyde emission regulations in the United States and Europe.
Two Australian voluntary standards make specific reference to formaldehyde in pressed timber products and include emission limits: AS/NZS 1859.1:2004: Reconstituted wood-based panels – Specifications – Particleboard; and AS/NZS 1859.2:2004: Reconstituted wood-based panels – Specifications – Dry-processed Fibreboard.
To be categorised as a ‘low-formaldehyde emission’ product, finished pressed wood products must meet test criteria levels of less than 1ppm of formaldehyde content. Most Australian-made particleboards and dry-processed fibreboards now meet the requirements for ‘low-formaldehyde emission’ products thanks to improved manufacturing and resin technologies, particularly the use of lignin-based adhesives.
All plywood products bonded with phenol formaldehyde adhesive will produce formaldehyde emissions, which will be at their highest levels immediately after manufacturing, progressively decreasing in a matter of weeks. Formaldehyde emission testing is performed shortly after manufacturing.
Research from numerous international organisations has shown that formaldehyde emission from phenolic resin bonded plywood is extremely low and will reduce even further once the phenolic coating is applied.
Plywood products, therefore, emit low to non-existent formaldehyde quantities with each variety of plywood giving different readings. The formaldehyde levels are dependent on the content of the adhesive glue lines of each plywood sheet as well as on the type of exterior coating on the plywood.
Maxiply can provide accurate information on formaldehyde emissions in Australian plywood products.
Useful data is also available on the websites of Engineered Wood Products Association of Australasia; Department of Health National Industrial Chemicals Notification and Assessment Scheme; and Australian Competition and Consumer Commission.