The use of a modified version of the accelerating rate calorimeter (ARC) as a screening method for the explosive properties of chemicals has been investigated. Definitive tests for classifying energetic chemicals for transportation are provided by UN Recommendations [United Nations, Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, third revised ed., 1999]. Recently, decomposition energy screening criteria were added to the recommendations, however, maximum rate of pressure rise in a closed vessel may provide a less conservative, more accurate screen. Pressure rate data for organic chemicals are compared to the UN test results. Preliminary screens are suggested to minimize the need for the larger scale, more expensive, and time-consuming UN-recommended testing. Results from this method are compared to those from published mini-autoclave data [M.W. Whitmore, G.P. Baker, J. Loss Prev. Process Ind. 12 (1999) 207-216]. Further work is planned to expand the range of chemical classes tested and to specify acceptable, conservative screening criteria. (C) 2004 Elsevier B.V. All rights reserved.