Barton Solvents Explosions and Fire

On the morning of 17 July 2007, an explosion and fire erupted at the Barton Solvents facility in Valley Center, Kansas (near Wichita). The facility was a distribution hub for a variety of industrial solvents. The incident began while a tanker-trailer was unloading Varnish Makers' and Painters' (VM&P) naphtha—a Class IB flammable liquid—into a 15,000-gallon above-ground storage tank.

The Chemical Safety Board (CSB) identified the "Causal Factor" as a static electrical discharge. VM&P naphtha is a "static accumulator," meaning it has low electrical conductivity and can hold a charge for a significant time. As the liquid was pumped into the tank, air was likely introduced into the piping, which, along with the "stop-start" nature of the filling, caused a rapid build-up of static electricity.

The ignition occurred inside the tank's "headspace." Unlike gasoline, which typically produces a vapour too rich to burn in a closed tank, the naphtha at ambient temperature created a "readily ignitable" fuel-air mixture. The spark was likely generated by the tank's internal liquid level gauging system. The float had a loose linkage that could separate slightly, creating a "gap" where the static charge could jump and create a spark. The resulting explosion launched the tank 130 feet into the air and ignited two more tanks. Projectiles, including tank tops and valves, were hurled into the surrounding community, striking a mobile home and a neighbouring business.

Just three months later, on 29 October 2007, a second, remarkably similar explosion occurred at a Barton Solvents facility in Des Moines, Iowa. That incident involved the filling of a 300-gallon portable steel tank with ethyl acetate, further reinforcing the CSB's findings regarding the systemic failure to manage static accumulation risks across the company.