CHEF Manual Chemical Hazards Engineering Fundamentals Version: 1.1 Revision Date: 13 September 2018 Document Owner: Louisa Nara, CCPS Global Technical Director CHEF Manual Chemical Hazards Engineering Fundamentals (CHEF) Manual Purpose This document provides an overview of methods and techniques used within the Risk Analysis Screening Tool (RAST). It is intended to fill the gap between qualitative and detailed quantitative methods. Feedback Request: Please provide feedback or comments on the content of this document to the RAST Committee, via the CCPS webpage (www.aiche.org/ccps) Revision History: A complete document history is located at the end of this document. Disclaimer It is sincerely hoped that the information presented in this document will lead to an even better safety record for the entire industry; however, neither the American Institute of Chemical Engineers (AIChE), the European Process Safety Centre (EPSC), its consultants, Center for Chemical Process Safety (CCPS) Technical Steering Committee and Subcommittee members, EPSC members board, their employers, their employers officers and directors, nor The Dow Chemical Company, and its employees warrant or represent, expressly or by implication, the correctness or accuracy of the content of the information presented in this document. As between (1) American Institute of Chemical Engineers (AIChE), the European Process Safety Centre (EPSC), its consultants, the Center for Chemical Process Safety (CCPS) Technical Steering Committee and Subcommittee members, EPSC members board, their employers, their employers’ officers and directors, nor The Dow Chemical Company, and its employees, and (2) the user of this document, the user accepts any legal liability or responsibility whatsoever for the consequence of its use or misuse. Copyright © 2018 American Institute of Chemical Engineers and European Process Safety Centre 13 September 2018 Page 3 of 131 CHEF Manual TABLE OF CONTENTS Contents Purpose ................................................................................................................................................ 3 Disclaimer ............................................................................................................................................. 3 TABLE OF CONTENTS ........................................................................................................................................... 4 1. INTRODUCTION ................................................................................................................................................ 12 Intended Audience ............................................................................................................................... 12 Sections .............................................................................................................................................. 12 Process Risk Management .................................................................................................................... 12 Hazard Evaluation and Risk Analysis ..................................................................................................... 13 Risk Assessment .................................................................................................................................. 13 2. HAZARD SCREENING ...................................................................................................................................... 16 Hazard Definition .................................................................................................................................. 16 Process Hazards .................................................................................................................................. 16 Safety Data Sheets (SDS) ..................................................................................................................... 16 Hazard Classification criteria under NFPA 704 ........................................................................................ 17 Hazard Classification criteria under European Dangerous Substances Directive ........................................ 17 Other Sources for Chemical Hazards Information .................................................................................... 18 Guidance for Determining Equipment or Unit Operations to Include in Hazard Evaluation ........................... 18 Hazard Screening Summary .................................................................................................................. 19 3.FLAMMABILITY .................................................................................................................................................. 20 Module Objectives ................................................................................................................................ 20 Fire Triangle ........................................................................................................................................ 20 Flammability Parameters....................................................................................................................... 20 Where to Obtain Flammability Data ........................................................................................................ 21 Estimation of Flammable Limits for Vapor Mixtures .................................................................................. 22 Example Estimation of LFL for Vapor Mixtures ........................................................................................ 22 13 September 2018 Page 4 of 131 Table of Contents CHEF Manual Estimation of Flash Point for Liquid Mixtures ........................................................................................... 23 Combustible Dusts ............................................................................................................................... 23 Liquid Aerosol or Mist ........................................................................................................................... 23 Limiting Oxygen Concentration .............................................................................................................. 23 Fire and Explosion ................................................................................................................................ 24 Fundamental Burning Velocity ............................................................................................................... 25 Dust Explosion Pentagon ...................................................................................................................... 25 Secondary Dust Explosion .................................................................................................................... 26 Deflagration Index ................................................................................................................................ 26 Maximum Explosion Pressure ............................................................................................................... 27 Minimum Ignition Energy ....................................................................................................................... 27 Managing Ignition Sources .................................................................................................................... 28 Adiabatic Compression ......................................................................................................................... 28 Static Electricity .................................................................................................................................... 29 Managing Electrostatic Discharge from Liquids and Solids ....................................................................... 29 4. TOXICITY ........................................................................................................................................................... 30 Module Objectives ................................................................................................................................ 30 How Toxicants Enter Biological Organisms ............................................................................................. 30 Toxicological Studies ............................................................................................................................ 30 Response to Toxic Dose ....................................................................................................................... 31 Lethal Concentration and Lethal Dose .................................................................................................... 31 Toxic Criteria for Risk Screening ............................................................................................................ 32 Emergency Response Planning Guidelines (ERPG) ................................................................................ 32 Inhalation Toxic Dose ........................................................................................................................... 33 Inhalation Toxic Mixtures ...................................................................................................................... 33 Example Estimation of Equivalent ERPG-3 for Vapor Mixtures ................................................................. 34 Relationship of Lethality to a Multiple of ERPG-3 ....................................................................................