The recent publication of Appendix A, 6 CFR part 27 establishes the rules for determining which chemical facilities are required to submit Top Screen data to allow DHS to determine which chemical facilities are at High-Risk for terrorist attack. The rules for all but one flammable release chemical are internally consistent; 10,000 lbs of the listed flammable liquid/gas on site and the facility is required to complete a Top Screen on-line filing with the DHS. In an earlier blog I explained that propane is the exception to the flammable release STQ.
Instead of the 10,000 lbs listed for other flammable release chemicals, propane has a 60,000 lb STQ. DHS set this STQ because this is the “estimated maximum amount of propane that non-industrial propane customers, such as restaurants and farmers, typically use” (page 43, Final Rule Appendix A). Furthermore, facilities are not required to count propane stored in tanks that can store less than 10,000 lbs of propane when determining if they meet the 60,000 lb STQ. This was done out of a “desire to exclude farmers and agricultural users of propane who routinely have three or more propane tanks for heating their homes and/or their chicken/turkey houses” (page 44).
In other words DHS set a special STQ for propane because they realized that propane is fundamentally different than most of the other chemicals listed in Appendix A to 6 CFR part 27. Most of the other chemicals are industrial chemicals; used in quantity only in an industrial setting. While propane is used in an industrial setting, principally as a fuel, it is also found in commercial, retail, and even residential facilities. Unfortunately, DHS (for political reasons apparently) decided that this made propane less hazardous; they were completely wrong.
A recent incident in Lynchburg, VA illustrates how wrong DHS was in setting a higher than normal STQ for propane. On Monday, November 26th, a car ran into a 1,000 gal propane tank in the parking lot of a hardware store. The collision caused the tank to rupture, leaking propane into the parking lot. Due to quick reactions of on-lookers, first responders, and power company personnel there was no source of ignition to cause the propane cloud to detonate in a violent fuel-air explosion.
If this had been a terrorist attack, instead of an accident, there would have been an ignition source (a simple incendiary device) in the vehicle that would have gone off two or three minutes after the collision and no one would have been able to prevent the fuel air explosion in that parking lot. The explosion could have left hundreds of people dead or injured in that commercial district from the primary explosion and the possible secondary explosions of fuel tanks in cars parked near by. It would have been a cheap, easy and effective terrorist attack.
These 1,000 gallon tanks (less than 5,000 lbs of propane when full) are common around the country. They are found on farms and ranches, in people’s yards, in shopping centers, and in parking lots at hardware stores. Most people would agree that breaching a tank and detonating the gas cloud on a chicken ranch would not rate high on a terrorist target list, but shopping centers and restaurants would probably be good terrorist targets.
Once this round of Top Screens is completed in January, DHS should seriously reconsider the STQ for propane. While a large number of rural propane tanks would not make the High-Risk facility cut off, a similarly large number of tanks at commercial facilities might make that cut. Just like other chemical facilities, DHS needs to be able to evaluate the potential riskfrom these 1,000 gal propane tanks on a facility-by-facility basis.
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