PHMSA, in consultation with the Transportation Security Administration of the Department of Homeland Security, published final rule HM-232F, titled Risk-Based Adjustment of Transportation Security Plan Requirements on March 9, 2010. This final rule modified the security plan requirements applicable to the commercial transportation of hazmat. Based on an evaluation of the security threats associated with specific types and quantities of hazmat considered to be “high consequence” if stolen and used for pernicious reasons, this final rule, effective 1 October 2010, narrows the list of materials subject to security plan requirements, thus reducing associated regulatory costs and paperwork. This plan helps you satisfy §172.