On November 20, 2007, the U.S. Department of Homeland Security ("DHS") published a list of "chemicals of interest," and applicable screening threshold quantities, that will set in motion the timeline for submitting certain information to DHS under Chemical Facility Anti-Terrorism Standards ("CFATS") that were first published in April 2007. The program is potentially applicable to a broad range of facilities based upon actual or planned possession of specific identified substances. The final list of chemicals of interest includes a number of substances that may be present at facilities that are not traditionally considered as "chemical facilities." For example, the list includes substances such as ammonia, ethane, propane, butane, methane and butenes, and includes substances present within certain product or commodity mixtures.

All facilities possessing or planning to possess the listed chemicals of interest in quantities exceeding the screening thresholds must complete a Top Screen within 60 days of November 20, unless exempt. Exempt facilities are those regulated under the Maritime Transportation Security Act of 2002 ("MTSA") or the Nuclear Regulatory Commission, as well as public water systems regulated under Section 1401 of the Safe Drinking Water Act and treatment works regulated under Section 212 of the Water Pollution Control Act. Facilities owned and operated by the Departments of Defense or Energy also are exempt.

A Top Screen is an online consequence screening questionnaire. Covered facilities must register for DHS' Chemical Security Assessment Tool ("CSAT"), and then complete the Top Screen process by providing information on facility location and chemical inventory. DHS will use the information provided in the Top Screen to determine whether the facility is "high risk." If the facility is not high risk, no further action is required, although a new Top Screen must be completed within sixty days of coming into possession of any chemical of interest exceeding its respective screening threshold quantity. For facilities determined to be high risk, CFATS establish risk-based performance standards and require such facilities to conduct security vulnerability assessments and develop site security plans within prescribed timeframes. The CFATS also raise unique legal issues regarding access to Chemical-Terrorism Vulnerability Information in the context of due diligence, time-sensitive hearing and appeal processes, and interaction with conflicting State programs.