Particle Board (PB)
Standard particle board is the standard, basic type of particle board product. It is not suitable for exterior use, or in interior areas where wetting or prolonged high humidity conditions are likely.
Since standard particle board is the standard or basic product, the practice has developed that the special products (MR and Flooring) are the ones specifically identified by name printed on the sheet or by colour code.The binder system used for standard particle board is urea formaldehyde. Paraffin wax is added to the surface layers to provide protection against accidental water spillage.
Moisture absorption will cause swelling, especially in the edges of a panel. Not all swelling will subside after drying out so it's important to use the correct type of particle board for each application. If in doubt it is best to use MR particleboard, which has a much lower response rate to wetting and will minimise the adverse effects of wetting.