Methylene diphenyl isocyanate (MDI) is a chemical used primarily to manufacture polyurethane foam used in a variety of products and industrial applications. Particle board, a big part of new-home construction, is manufactured using adhesives from MDI. MDI reacts with polyols in the manufacture of polyurethane. It is the most produced diisocyanate, accounting for 61.3% of the global market in the year 2000. MDI is an intermediary in the manufacture of urethane-based materials such as polyurethane rigid foam--which account for 53 percent of MDI use--as well as flexible foam, binders, elastomers, adhesives, sealants, surface coatings, and fibers. Rigid polyurethane foam is used as an insulating and cushioning material in construction, appliances, packaging, and transportation. MDI-produced polyurethane is also used for binding wood chips and flakes together to make particle board. The major application of MDI is the production of rigid polyurethane. These rigid polyurethane foams are good thermal insulators and used in nearly all freezers and refrigerators worldwide, as well as buildings. Typical polyols used are polyethylene adipate (a polyester) and poly(tetramethylene ether) glycol (a polyether). MDI is also used as an industrial strength adhesive, which is available to end consumers as various high-strength bottled glue preparations.