CFATS: What You Need to Know About Re-Tiering

The Chemical Facility Anti-Terrorism Standards (CFATS) program has begun implementation of the Chemical Security Assessment Tool (CSAT) 2.0 and the enhanced tiering methodology. The CFATS risk-assessment and tiering methodology is a foundational element of the program used to determine which of the tens of thousands of facilities in possession of threshold quantities of certain chemicals are at high-risk of terrorist attack or exploitation.

Last fall, the Department of Homeland Security (DHS) began reevaluating risk for about 27,000 facilities that possess the Chemicals of Interest (COI) listed in Appendix A at or above screening threshold quantities. The Department is using the enhanced risk methodology, which takes all elements of risk and several new components into consideration when determining if a facility is high-risk.

This means that all facilities that possess threshold quantities and concentrations of COI are required to submit a new Top-Screen survey to DHS – this includes facilities that have previously submitted Top-Screens and were determined to not be high-risk. More than 11,000 facilities have already received notification from DHS to resubmit a new Top-Screen. DHS began issuing the tiering results to facilities at the beginning of April, and is likely to continue doing so for the next two years.

CFATS made a number of enhancements to the methodology that make it a more accurate reflection of a facility’s risk. Based on analysis of a representative sample drawn from the enhanced methodology results, DHS believes that as notifications continue some facilities may see a change in their tiers. 

Some facilities that were previously not covered under CFATS may find themselves covered, while other currently-covered facilities may no longer be considered high-risk. Facilities may also see their tier shift within the covered population. Some of the primary drivers behind these shifts were:

  • A large number of facilities reporting new COI or otherwise modifying their holdings when they updated the Top-Screen.
  • Tier decreases for some theft/diversion COI resulting from the implementation of physics-based modeling for this security issue.
  • Changes (increases and decreases) in tier levels for release-toxic COI due to an improvement in how population density data is used in plume modeling. 
  • Increases to number of facilities tiered for some theft-diversion chemical weapon precursors due to new physics-based modeling.

The enhanced risk-assessment and tiering methodology is the result of over three years of work in accordance with the guidance provided by Congress, the recommendations of an external peer review panel composed of government and private sector experts, and recommendations by the Office of Inspector General (OIG) and Government Accountability Office (GAO). The enhanced methodology was also reviewed by a group composed of industry and government experts, the Homeland Security Studies and Analysis Institute (HSSAI) and Sandia National Laboratories. 

Stakeholders like SOCMA have a strong interest in the tiering efforts, and DHS is committed to remaining transparent and keeping stakeholders informed. To discuss tiering trends and to respond to questions from facilities, DHS is hosting two public webinars:

For more information, see the Tiering Methodology webpage. For questions, please email

Return Home