In 1941, researchers in Dow's Chemical Physics Lab found a way to make foamed polystyrene. Led by Ray McIntire, they had "rediscovered" a method first discovered by Swedish inventor C. G. Munters. Dow acquired exclusive rights to use Munter's patents and found ways to make large quantities of extruded polystyrene as a closed cell foam that resisted moisture. Because of its insulating properties, buoyancy and "unsinkability", it was adopted in 1942 by the U.S. Coast Guard for use in a six-person life raft. Styrofoam can be used for building materials, including insulated sheathing, pipe insulation and floral and craft products. Styrofoam insulation has been used in many notable buildings and facilities in North America. The Dow product can be identified by its distinctive blue color.
Styrofoam can be used under roads and other structures to prevent soil disturbances due to freezing and thawing.
The word styrofoam is often used as a generic term for expanded polystyrene foam, such as disposable coffee cups, coolers or packaging material, which are typically white and are made of expanded polystyrene beads and are very different from Styrofoam.