Yes it is, and this is an important fact to consider. These blue castings amount to nice, albeit limited, reproductions, but they are reproductions nonetheless. This is an extremely important piece of information to remember as many people find it hard to tell the difference between some plastics and the blue urethane, though you don't have to spot the difference if you can just remember the process. Other oddball action figures and accessories have turned up in this blue urethane and it's important to note that the same rule applies to them. If it's a Star Wars toy that's from 1986 or earlier, and blue, then it cannot be an authentic hard copy - it's just a reproduction.
People sometimes confuse the blue urethane with regular plastic because it has a similar feel to it.
However, the blue material is very hard and doesn't have the flex that regular plastic does. Especially on older Star Wars hard copies, the urethane is very heavy compared to plastic which is a dead giveaway. It's so hard that it almost feels like ceramic pottery. Unfortunately, the newer, blue material is much lighter than the old urethane resins and makes it harder for the novice to quickly differentiate from regular injection-molded plastic. This can be a point of confusion, but the good thing here is that one can know what they are looking at, not by the material, but by the piece itself.