Vinyl chloride entered the spotlight after the Feb. 3 Ohio train derailment. But the hazardous substance has been around for decades and is everywhere " from buildings and vehicle upholstery to children's toys and kitchen supplies " and factories have been emitting the EPA-designated toxic chemical into the air for years. The train that derailed had the manmade and volatile compound on board, prompting temporary evacuations. But the derailment isn't the first time vinyl chloride has alarmed experts. Experts say that the volatile compound, "used almost exclusively by the plastics industry," has "leached into groundwater from spills, landfills, and industrial sources," and that people who live around plastic manufacturing facilities "may be exposed to vinyl chloride by inhalation of contaminated air." According to the EPA's Toxics Release Inventory (TRI), which "tracks the management of certain toxic chemicals that may pose a threat to human health and the environment," there are 38 TRI facilities in 15 states " mostly around the Gulf of Mexico and the eastern U.S. " that use vinyl chloride, emitting about half a million pounds of the substance every year. The problem begins at vinyl chloride's origins. It's generated from ethane, which is obtained through fracking natural gas. The U.S. Energy Information Administration said ethane production hit a monthly record last year of more than 2.4 million barrels per day. The global PVC market is expected to become a $56.1 billion industry within the next 3 years.