The ERG provides a comprehensive reference for hazardous materials organized by which identifiers?

• A. Name and ID number
• B. Hazard class
• C. Chemical composition
• D. Manufacture date

Answer: (A)

On-scene safety hinges on quickly matching a hazardous material to a specific reference. The ERG is organized by identification numbers—the UN/NA four-digit codes—and the material’s name. This setup lets responders flip to the exact entry for that substance and read the recommended actions right away, using both the ID and the common name as the anchor. Hazard class is useful context, but it isn’t the primary way the book is laid out, so materials with the same class can appear far apart and slow reference if that were the organizing principle. Chemical composition and manufacture date aren’t navigational anchors in the ERG, since the crucial need is to identify the material reliably by its ID and name to guide immediate response. So the most accurate description is that the ERG is organized by name and ID number.