IST Definition – No Political Cover

As I mentioned last week the Center for Chemical Process Safety (CCPS), at the behest of the DHS Chemical Security Analysis Center (CASC), produced a technical definition of inherently safer technology (IST). Having had a chance to read (and re-read) the document produced by CCPS, I am completely unsurprised that the definition will not provide political cover for either side of the political IST debate.

Two Edged Sword

The CCSP document cautions that this definition will not provide the guidance necessary to resolve the IST debate. The authors note that:

“The definition summarizes a very complex technical philosophy in a short and concise statement to make IST understandable to a broad, non-technical audience. However, actual identification of potential IST options, and evaluation of whether or not they make sense to implement at a specific facility requires a more extensive understanding of the technology involved than this definition provides.” (para 3.3, pg 7)

Opponents of the mandatory IST proposals being discussed as a potential component of a comprehensive CSAT re-authorization program will seize on this a justification for their continued opposition to an IST mandate. They will note that making the security professionals at DHS judges of a complex engineering decision is just not practical.

Proponents of an IST mandate will counter with a quote from the detailed discussion in Appendix B. That quote addresses the political component of the IST decision process by noting:

“Ultimately, society must decide which hazards and risks it wants to manage primarily with inherently safer design approaches, and which hazards and risks will be managed with other approaches (active, passive, and procedural).” (pg B-2)

One clear point that is made in the report is the fact that, while IST can be applied to existing facilities and technologies, it is most effective in the process design phase.

“While IST applies throughout the life cycle of a process, plant, or material, the greatest opportunities for significant IST benefits are early in the life cycle, before the technology becomes deeply integrated into the infrastructure of an industry from raw material suppliers through final product users, and before major investments in plant and equipment are made.” (pg B-1)

Levels of Inherently Safer Design

This report quotes from the CCSP book on inherently safer technology, noting that there are two levels of IST implementation; first and second order IST processes. They are described as (pg B-2):

“First Order inherently safer design refers to the identification of alternatives that completely eliminate a particular hazard. Note that, as discussed above, this does not say anything about the impact on other hazards, which may be increased, decreased, or remain unaffected by the change.”

“Second Order inherently safer design reduces the magnitude of a hazard, or makes an accident associated with a hazard less likely to occur, by the design of the equipment, and not through add-on safety devices. Again, this does not say anything about the impact of the change on other hazards, which may be increased, decreased, or remains unaffected.”

The report goes on to explain that:

“When you consider all of the multiple hazards associated with any technology, it is unlikely that it will ever be possible to manage all of them inherently, and layers of protection [risk management equipment and management systems] will always be required as a part of the total risk management program. Inherently safer design concepts can be used to make these layers of protection inherently more reliable and robust.”

Definition Shortcomings

The report identifies two principle shortcomings in the utility of definition provided in the report. Those are (para 3.4, pg 7) the lack of:

● “Specific methodologies for engineers and managers to identify IST alternatives.”
● “Methods for measuring the IST characteristics of alternative technologies.”

While most IST proponents will be quick to point to some very visible IST alternatives for many release toxic COI, those alternatives would hardly be a comprehensive list of alternatives. IST application to existing processes would be better served if a one-time evaluation of a comprehensive list of alternatives were done. This would allow the facility to then concentrate on implementing the most effective alternative(s) or addressing the layers of protection necessary when an IST alternative is not practical.

The biggest obstacle to achieving a political consensus on an IST mandate is the lack of a methodology to effectively measure the relative efficacy of IST alternatives. If each facility is allowed to establish and implement their own method of evaluating an IST methodology then the current IST proponents would be unsatisfied every time a facility found an IST alternative not practical to implement.

It seems to me that resolving these two issues will be a pre-requisite to getting the necessary political agreement to establish an IST mandate as part of the CFATS process. Neither will be politically or technically easy to accomplish. This definition of IST is an important first step and CASC is to be commended for their initiative in commissioning this report.