Two Day Chemical Hazards Engineering Fundamentals (CHEF) Workshop | AIChE

Two Day Chemical Hazards Engineering Fundamentals (CHEF) Workshop

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    Hilton Americas and George R. Brown Convention Center, Houston, TX

    Registration Information:

    Member Rate: $1,200

    Non-member Rate: $1,500


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    Note: You can also add this course as a ticketed event to your conference registration, or call our customer service at  800.242.4363 to register

    CHEF Course 


    Chemical Hazard Engineering Fundamentals (CHEF) is a compilation of correlations and methods which are used in the various hazard evaluation and risk analysis steps within the Risk Analysis Screening Tool (RAST).  The methods selected are generally well defined and well validated, reasonably simple to apply, and provide results which appear consistent with more sophisticated models. 

    This course will enable users to become familiar with concepts and simple methods so that evaluation teams can perform screening level Hazard Identification and Risk Analysis (HIRA). Example problems are provided so that users understand the limitations of the methods and when to utilize more advanced techniques or to engage a Subject Matter Expert.

    Included in CHEF are the:

    • Identification of chemical (flammability, toxicity and reactivity) and operational hazards
    • Techniques for development of incident scenarios
    • Source models for estimation of leak rate, evaporation rate, vapor dispersion, and explosions
    • Effect models for estimation of human harm from toxic releases, flammable releases, and explosions
    • Techniques for evaluation of likelihood (historical data, fault tree, and event tree), and
    • Quantification of risk (i.e., risk is a function of the frequency times consequence)

    CHEF also includes an Excel calculation aid to help study teams understand and utilize the correlations used to evaluate leak sources, vapor dispersions, and explosion overpressures and their impact. These correlations provide users with powerful screening techniques to help an organization prioritize its overall process safety risks – a bridge between the qualitative approach and quantitative approach – before investing in complex, detailed quantitative hazards and risk assessments (e.g., Quantitative Risk Assessments, QRAs).

    A CHEF manual and the calculation aid are available at no charge from the CCPS. Attendees should download this manual and aid prior to the workshop. Download CHEF Manual and CHEF Calculation Aid

    CHEF Course Outline

    Day 1:

    1 – Introduction

    • Overall Work Process Steps for a Hazard Identification and Risk Analysis (HIRA) study

    2 – Hazard Screening

    • Hazard Definition
    • Where to find Hazard Information
    • Criteria for Hazard Severity such that an Analysis may be Warranted

    3 – Flammability

    • Flammability Characteristics
    • Ignition Sources

    4 – Toxicity

    • Toxic Criteria for Risk Screening
    • Toxic Dose
    • Probit Models

    5 – Reactivity

    • Categorization of Reactivity Hazards
    • Test Methods

    6 – Hazard Evaluation

    • Determining “What can go Wrong” in our Chemical Processes.
    • Overview of Hazard Evaluation Techniques
      • Checklist
      • Relative Ranking
      • What-if Analysis
      • HAZOP

    Day 2

    7 – Introduction to Consequence and Risk Analysis

    • Definition of Undesired Consequence and Risk
    • Risk Matrix

    8 – Source Models

    • Discharge Models
    • Droplet Evaporation
    • Evaporation from Liquid Pools

    9 – Vapor Dispersion

    • Jet Mixing
    • Dense Gas Dispersion
    • Neutrally Buoyant Dispersion

    10 – Explosions

    • Physical Explosion
    • Confined Space Explosion
    • Vapor Cloud Explosion

    11 – Impact Assessment

    • Incident Outcome
    • Quantification of Human Harm

    12 – Likelihood Evaluation

    • Failure Frequency from Historical Data
    • Overview of Estimation Techniques
      • Fault Tree
      • Event Tree
    • Risk and Tolerable Frequency

    13 – Link to Risk Analysis Screening Tool (RAST)