We spray our premium foam insulation into homes to make sure the isn't any air escaping through the rim joist and provide comfort.
Typically water based and very light density, this foam has the consistency of angel food cake. It weighs about .5 pounds per cubic foot. Air bubbles inside the foam burst open, hence the name "open cell." Some types of open and closed cell foam have a soy base, although this soy base is still typically accompanied by strong chemicals.
Typically oil-based, high density (1.25-2 pounds per cubic foot) hard foam. It is a fairly mature product that has been out for 30+ years. Made of two parts, it catalyzes when mixed and cures quickly. Air bubbles inside (cells) do not burst, hence the "closed cell" designation.