An explosion and five alarm fire occurred at GT Products, Inc on July 8, 2011 in Grapevine, Texas. The explosion happened before 3:00 pm and became a five alarm fire by 4:30 pm The company manufactures silicone and urethane products in it's 50,000 square foot facility. It has been in business since 1984. The fire was extinguished by 5:30 pm. Water that was utilized by the fire department was leaving the property via a drainage ditch. Booming material and absorbent pads were used to prevent some of the water from leaving the property. The storm water drain goes under the State Highway 114 and travels north. Black material was observed on the surface of the water on both the south and north side Highway 114. Business are located on the east and west side of the property.Formaldehyde may form when the silicone is heated to 300 degrees F.There may be 2,4-toluene diisocyante associated with urethane. Environmental Investigators from TCEQ Region 4 and environmental staff from the City of Grapevine were present at the facility.