(41b) "Fit-for-Purpose" Consequence Analysis As Demonstrated By Anhydrous Ammonia and Aqueous Ammonia

Correctly evaluating hazard sources, release, propagation, dispersion, exposure, and consequence can be a difficult but essential task for successfully prioritizing—and preventing and or mitigating—consequences of hazard release. Evaluation of an example illustrates how this may be performed efficiently and effectively by a "fit-for-purpose" approach.

Ammonia is a chemical with numerous and varied uses: antimicrobial agent, catalyst, cleaner, fertilizer, fuel, leather treatment, pH adjustment, refrigerant, solvent, washing textiles, wood treatment, and as a raw material. Anhydrous ammonia is considered a dangerous form for which substitution of hydrous (aqueous) ammonia is referenced frequently as an example opportunity for improving inherent safety. Such a substitution may seem to be a question only if the hydrous (aqueous) form is acceptable for the proposed application. Safe realization of the objective, however, cannot be assumed.

Using the substitution of hydrous (aqueous) ammonia for anhydrous ammonia, this paper presents how to evaluate hazard sources, release, propagation, dispersion, exposure, and consequence in a “fit-for-purpose” manner to successfully prioritize—and prevent and or mitigate—consequences of hazard release. The technical substance is presented, and observations and lessons drawn from it are discussed for different applications.