Chipboard, also called particleboard, is made from a slurry of wood scraps, sawdust and glue that is dried in sheets and pressed into boards. According to the Composite Panel Association, many manufacturers also incorporate formaldehyde and melamine resins into the mix. Quality chipboard receives two pressings: The first is at room temperature, and the second at temperatures up to 428 degrees F.
There are three types of chipboard. Hard chipboard is the strongest of the three and most closely resembles actual lumber. Medium chipboard is slightly more flexible and cannot bear as much weight as the hard variety. Soft chipboard is pliable and weak.
Chipboard is a composite material and vulnerable to water damage, even when sealed and painted. It is absorbent and prone to damage from water and water-based dyes and stains. Chipboard's absorbency also makes it a poor choice for outdoor uses and for humid indoor environments such as bathrooms. Despite this, sealed chipboard makes an excellent subfloor beneath vinyl tiles and other types of bathroom flooring.
When cut, chipboard releases large quantities of sawdust and tiny wood flakes, according to expert Chris Baylor from the website About. Boards produced with toxic formaldehyde also release that chemical during cutting and sanding. This is a potentially dangerous respiratory hazard. Baylor recommends wearing a cone mask or respirator while cutting any type of chipboard. Going outside to cut chipboard reduces the chance of inhaling particulates.