Medium density fibreboard (MDF) is made from
lingo-cellulosic fibres derived from defibrated wood
chip. It is typically composed of 85-100% softwood
and 0-15% hardwood. The material is often bound
together with a urea-formaldehyde resin. It may
leach out formaldehyde vapour in storage, and the
resin can decompose when machined due to heat
and gives out formaldehyde.