The building materials unit manufactured lumber, plywood, fiberboard, particleboard, and laminated veneer lumber products. In addition to OSB, Norbord manufactures particleboard, Medium-Density Fibreboard (MDF) and related value-added products. Wood particleboard is manufactured from sugar cane bagasse. A variety of floor materials can be sanded, including timber, cork, particleboard, and sometimes parquet. Triboard, conceived in the 1980s, competes with older technologies such as particleboard and MDF. Sawdust is the main component of particleboard. The 1981 stairs to the ground floor have been infilled with particleboard flooring. In 2007 Columbia added PureBond formaldehyde-free particleboard to its product range. Most other early particleboard manufacturers used similar processes, though often with slightly different resins. Fine dust and chemicals are released when particleboard is machined (e.g., sawing or routing). It is also an ingredient of mosquito coils and glue for carton and particleboard. More recently, graded-density particleboard has also evolved. This type of board is known as three-layer particleboard. Its particleboard lines are located in Cowie, Scotland and South Molton, England.