Section 563 of the 2008 Consolidated Appropriations Act, Secure Handling of Ammonium Nitrate (Section 563) granted the Department of Homeland Security (DHS) the authority to regulate the sale and transfer of ammonium nitrate “to prevent the misappropriation or use of ammonium nitrate in an act of terrorism.” In October 2008, DHS published an Advanced Notice of Proposed Rulemaking (ANPRM) detailing the activities expected to be covered under the ammonium nitrate regulations and seeking comment from interested parties. In August 2011, DHS published an ammonium nitrate Notice of Proposed Rulemaking (NPRM).
While ammonium nitrate exists in various forms and concentrations, DHS is primarily concerned with the chemical when used an explosive (e.g., in the mining industry) or when used as fertilizer mixed with fuel oil to create an explosive mixture known as Ammonium Nitrate/Fuel Oil (ANFO). Given the availability of small-scale packaging (e.g., 50-pound bags) of ammonium nitrate fertilizer used in agriculture-related operations, the chemical is susceptible to theft and misuse in making an Improvised Explosive Device (IED).
For the purposes of the NPRM, DHS defines Ammonium Nitrate as:
Pursuant to Section 563, DHS expects to regulate the following categories of activities: