This document is organized into five sections:
- Introduction: Provides information on the background, purpose, scope, audience, and organizational structure of this document.
- Operational Phasing and Planning Framework: Provides an overview of key decision process guidelines, operational phasing, and an overarching planning framework for chemical incident consequence management.
- Hazardous Chemicals and Their Characteristics: Identifies the various types and characteristics of hazardous chemicals to help inform both the immediate response and longer-term remediation and re-occupancy decisions.
- Principles of Risk Assessment for Hazardous Chemicals: Provides background information on risk assessment considerations for hazardous chemicals.
- Key Elements in Clearance Decision-Making: Presents points of consideration for each of the key activities required for successful remediation and re-occupation of areas/sites impacted by a large- scale chemical incident, as well as references for further scientific or expert guidance.
Substantial additional references and background information are provided in the appendices. Appendix A discusses available hazardous chemical-specific exposure guidelines (environmental health-based levels) and factors to consider when selecting appropriate types of values to apply at each stage of an incident (e.g., emergency response, remediation activities, establishing remediation goals, and making clearance decisions). Appendix B presents example scenarios and case studies based on real-world incidents and exercise events.
The procedures described in the appendices are based primarily on historical cases of large-scale HAZMAT responses and large-scale exercises involving chemical incident scenarios. It is assumed that those officials involved in the decision-making process will have (or will be advised by individuals who have) appropriate background and field experiences regarding the technical aspects of chemical incident consequence management which is the focus of this document. The approaches as outlined in Appendix B do not replace or eliminate the need for the informed judgment of competent risk assessors and managers for site-specific decision-making.