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  • Writer's pictureTom Petersen

New Homeland Security Rules May Apply To You

Updated: Aug 29, 2023

On Friday, November 2, the federal Department of Homeland Security (DHS) released (through a pre-publication notice) the final Appendix A to the Chemical Facility Anti-terrorism Standards (CFATS). This Appendix is the List of Chemicals of Interest and associated screening threshold quantities. Publication of the final list (Appendix A) in the Federal Register will trigger the 60 day period for facilities that possess greater than the Screening Threshold Quantity (STQ) of any listed chemical to register and file with the DHS using Top Screen, the DHS online tool.

There are about 300 chemicals on the list. This includes chemicals such as ammonia, chlorine and propane. Due to the number of chemicals on the list and the fact that many are commonly used at industrial facilities, it is important to take some time to compare this list to the list of chemicals at your facility and determine if you are required to report.

DHS will use the information they receive through this reporting to make preliminary determinations as to the security risk of your facility. This in turn is meant to ensure that higher risk facilities are given appropriate levels of security. Not all facilities that are required to complete this submission will be subject to further regulation. CFATS requirements include a Security Vulnerability Assessment and a Site Security Plan.

Some key issues and questions have been resolved by DHS with the release of Appendix A including:

Screening Threshold Quantities (STQ) – STQs have increased for many compounds since the draft was published.

Categories of Chemicals of Interest – The categories of each Chemical of Interest (the reason why the DHS is concerned about the chemical) are included in the final list and in some cases there are different STQs for different categories. These categories include: Release (includes toxic, flammable & explosive chemicals), Theft and diversion (includes chemicals that can be made into weapons/explosive devices) and Sabotage and contamination (includes chemicals that could be mixed with readily available chemicals and result in a dangerous situation).

Mixtures – The issue of mixtures has been resolved by the final list. The list contains maximum concentration percentages, “commercial grade” designation or a placarded amount. Many are set at a minimum concentration of 1.00% so MSDS sheets for commercial products will need to be checked.

Any amount – The designation of “any amount” has been replaced by actual amounts ranging from “Cumulative amount of 100 grams,” up to “20,000 pounds” and even 60,000 pounds for propane.

Propane – The STQ for propane is 60,000 pounds (not counting propane in containers of 10,000 pounds or less) where it had been 7,500 pounds on the originally proposed list.

No longer on the list – Carbon monoxide, acetone and urea, which were on the originally proposed Appendix A, are no longer listed.

If you have specific questions about the regulation and the final Appendix A, please contact Tom Petersen at 215-881-9401 or We would be pleased to assist your facility in the submission and the development of the plans outlined in the CFATS regulation.

Number 44 part 1



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