Tagging of expls

The basic purpose of identification tagging of expls is to provide information on what expl was used, who manufd it, and under ideal circumstances, the last legal purchaser of the expl. One can distinguish three categories of identification taggants 1) material that will not survive detonation but can provide the above information if an undetonated criminal device is recovered 2) radioactive material and 3) material that will survive detonation... 

There is another somewhat esoteric cost associated with tagging of expls, namely liability in law suits resulting from expl accidents. It is probable that plaintiffs lawyers will try to attribute accident cause to the inclusion of taggants. How courts will react to such allegations and who may be found liable is uncertain at this time. However, it is conceivable that such liability costs can be large... 

In more recent years, as the kinetics of thermal decompn of expls began to be studied, questions arose whether partial vaporization and vapor phase decompn were important at temps well below the boiling point of the expl. Very recently, as criminal bombings became a matter of international concern, bomb detection schemes based on detection and identification of vapors of the expls used in such bombs were proposed. Expl vapor detection will not be addressed in this article (see under Tagging of Explosives in Vol 9). The interested reader is referred to a summary contained in Ref 25... 

Cost factors of expl tagging will be considered in the next section. In view of the above discussion, recalling that there can be serious compatibility problems of currently preferred taggants and expls, and considering that detection tagging is still in its infancy, it seems that immediate or near-future Congressional action to make tagging mandatory would be premature... 

It is instructive to consider how costs are apportioned to the various facets of the tagging programs, what impact total costs will have on the price of expls, and what expl user reaction might be to this increase in price. Tables 12 and 13 show material costs for the baseline identification and detection programs respectively. These costs are broken down by type of expl tagged... 

Expl limits of styrene in air are 1.1 to 6.1% at 30° Fire point (Tag open cup) is 94 °F. Styrene polymerizes exothermally at above RT conditions. A run-away polymerization can be expl... 

The addition of a secondary solute or wavelength shifter can serve to offset much if not all of the action of tagged nitrocompds in reducing counting efficiency. For expl nitrocompds, a shift of the emission spectrum considerably into the visible region where absorption effects are not so pronounced is clearly indicated. The secondary solute POPOP has been found to be most efficient for this purpose (Ref 2). This enhanced effect on the scintillation process is illustrated in Fig 2 for p-Nitrotoluene... 

Although criminal bombings are an international problem, this article is limited to consideration of the bombing threat in the USA and the use of tagged expls to control it... 

Detonation of large quantities of tagged expls tends to reduce the number of surviving taggants... 

It should be emphasized that the state of development of viable expl detection schemes is much less advanced than that of identification tagging. Very many serious problems are still unresolved. Consequently, any estimates of the efficacy and applicability of detection tagging are even more oracular in nature than those for identification tagging... 

The ability to detect tagged expl products in a controlled-access scenario is the final objective of the vapor taggant development effort. To accomplish this, there are three steps (1) placement of the taggant in an expl product (2) extraction of the vapor taggant from the test object and (3) use of a detector of sufficient... 

This cost is predicated on unencapsulated taggant levels of 0.025% for both identification and detection tagging for the major expl categories, and a price of 55/lb for the former and 40/lb for the latter... 

From the point of view of the manufacturer or user, the important criterion is the additional cost that tagging expls will necessitate in the market place. OTA s estimates, shown below, project a substantial cost increase for all expl categories (except possibly BlkPdr) ... 

Definition of a realistic range of effectiveness for detection tagging (as it applies to the overall expl threat) is much more uncertain than for identification tagging. Within this large uncertainty, it appeared that detection tagging is not worthwhile from an economic point of view, but may still be justifiable in terms of its potential to reduce very infrequent but very costly bombings... 

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