I ran into an interesting report last week that addressed the potential threat of a terrorist attack using truck-load quantities of hazardous materials as a weapon. The unclassified report was prepared by the Mineta Transportation Institutes (MTI) National Transportation Security Center of Excellence at San Jose State University in California. It was produced at the request of DHS.
While I have some disagreement with some of their conclusion and I am concerned with some of the things that were left out of their discussion, I think that this document is certainly a good starting point for further discussion on the topic. Their conclusion that gasoline tanker trucks pose the largest threat for use in a terrorist attack is particularly timely given the current discussion about gasoline terminals and CFATS.
HAZMAT as Weapons
One of the interesting things that MTI has done is to look at the comparative effectiveness of different classes of hazardous materials as weapons. They look at toxic inhalation hazard (TIH) chemicals, explosives, flammable gasses and flammable liquids transported in full truck quantities on public highways.
TIH Trucks: They note that TIH loaded trucks, if successfully attacked, would have the greatest potential for causing casualties, but note that the wide variety of variables that must be controlled to bring about those casualties makes it extremely unlikely that such an attack could be successfully made.
Explosives Trucks: Explosives have the advantage of being very effective weapons of mass effect and relatively easy to employ. The major draw back that this study finds is that, because of this effectiveness, there are additional security measures employed to protect explosives trucks and there are relatively few of them on public roads available for use as weapons.
Flammable Gasses Trucks: Flammable gasses such as propane or LPG would seen to be good potential weapons because they are both flammable and form vapor clouds that can be detonated. MTI notes that both of these weapon effects are hard to control and direct. Short of creating a BLEVE (boiling liquid expanding vapor-cloud explosion), the number of variables that must be controlled to effect a vapor-cloud explosion (VCE) are technically challenging. The major advantage to using these trucks as weapons is that they are much more readily available than are TIH or Explosives trucks.
Flammable Liquids Trucks: Gasoline trucks are, by far, the most readily available hazmat found on the roads and byways of the United States. This makes them readily accessible to terrorists of all skill levels. The MTI report does not address the VCE potential for gasoline, but does provide extensive discussion about the use of gasoline fed fires as a weapon against both people and infrastructure.
I spent 15 years in the US Army as an Infantry NCO. After getting out of the Army I started working in the chemical industry, getting my BSc Chemistry degree while working as a technician. I spent 12 years working as a process chemist in a specialty chemical company. I'm now working as a QA Manager in a specialty chemical manufacturing facility.