The fire was at the plant on Goodyear Dr. at La Porte Freeway.
According to the Pasadena Fire Department, the blaze was confined to a pit exterior to the plant's buildings.
It was originally reported that tires were burning. Officials said it was some kind of rubber.
No injuries were reported. The fire was tapped out within about 15 minutes, officials said, and a hazmat team responded as a precaution.