On Nov. 20, 2007, the Department of Homeland Security (“DHS”) published the final version of Appendix A to the Chemical Facility Anti-Terrorism Standard in the Federal Register. (6 CFR Part 27). Appendix A lists chemicals of interest and screening threshold quantities, or STQs. Facilities which meet or exceed Appendix A thresholds must complete and file an initial security assessment, known as a Top-Screen, with DHS by January 19, 2008. DHS will use the Top Screen to determine if the facility presents a high level of security risk.

Download Federal Register (PDF: 4.25MB).