Feb. 3--The massive Barton Solvents explosion in Valley Center last July could prompt a national safety advisory for facilities that transfer and store certain flammable liquids, a federal investigator says.
The advisory, if approved by the U.S. Chemical Safety and Hazard Investigation Board, would urge handlers nationwide to take a series of precautions.
They would include measures to prevent the accumulation of static electricity -- which was blamed for the explosion -- and a step to eliminate a key component in a fire -- oxygen in storage tanks.
"We're going to use the Barton incident as our example of what can go wrong and how it could have been prevented," said Randy McClure, the safety board's lead investigator on the Valley Center incident.
"We think there are similar businesses vulnerable to this same type of accident," McClure said.
The advisory could be issued in March or April.
The advisory would be for any facilities that pump and store flammable solvents, as defined by National Fire Protection Association standards.
Meanwhile, a top Barton Solvents official says the company will be testing a system that removes oxygen from storage tanks. That system could be used when the company rebuilds its Valley Center tank farm or moves to Bel Aire or some other location in Sedgwick County. The system would be among the steps recommended in the safety advisory.
A recently completed state investigation has concluded that the July 17 explosion occurred when a static electric charge ignited vapors in a solvent tank that was being filled. Since the incident, officials have said they suspected static in the tank.
For an explosion to occur three conditions must be present: an ignition source, fuel and oxygen. Removing any one of the elements greatly decreases the chance of a fire.
The 54-page state report, compiled by state fire investigator Dave Higday and obtained last week by The Eagle, lists possible contributing factors in the tank explosion, among them:
- The liquid's natural tendency to accumulate a static charge.
- A lack of additives to reduce static.
- A nearly empty storage tank that could have caused the liquid to splash when the tank was being filled. Agitation can generate static.
- Air being pushed into the tank from a pump that continued to run. That could have agitated the tank contents and increased the ignitable mixture.
- How fast the liquid was being pumped. A higher velocity can create more static.
The explosion launched the 10 1/2 -foot-wide, 24-foot-tall tank far enough into the air that when it landed on plant property, it nearly collapsed, Higday said.
Other explosions and flames engulfed the tank farm, creating smoke that was visible for miles. No one was injured, but authorities urged Valley Center residents to evacuate.
Asked about the potential for harm that day, Higday said, "We had debris that went 200 to 300 yards. If it would have hit somebody, they would have been dead... or seriously injured."
One tank's top struck the corner of a mobile home near the tank farm. The residents weren't home. Another heavy piece struck the metal building of a nearby business.
Barton Solvents, which is weighing whether to re-open in Valley Center or elsewhere in the county, will be testing a costly safety measure that could prevent another such explosion, said company president Dave Casten.
The measure involves pumping nitrogen into above-ground storage tanks to deplete the oxygen around the flammable liquid. Without oxygen, a fire or explosion is much less likely to occur.
Nitrogen blanketing, as it is called, is one of three safety steps among the recommendations in a draft of the national safety advisory, said McClure, the safety board investigator. The advisory is being prepared by the investigative team led by McClure.