According to Engstrand, "Lawson was acknowledged at the time, but his name later became confused with company president Norman B. Larsen."[4][5][2] "WD-40" is abbreviated from the term "Water Displacement, 40th formula", suggesting it was the result of the 40th attempt to create the product.[1] The spray, composed of various hydrocarbons, was originally designed to be used by Convair to protect the outer skin of the Atlas missile from rust and corrosion.[6][7] This outer skin also functioned as the outer wall of the missile's paper-thin fuel balloon tanks, which were so fragile that, when empty, they had to be kept inflated with nitrogen to prevent them from collapsing. WD-40 was later found to have many household uses[1] and was made available to consumers in San Diego in 1958.[6]