The Emergency Response Guidebook (ERG) is used to:
Correct. The ERG cross-references the four-digit ID number from the placard or shipping paper to a guide page with isolation distance, response procedures, and first aid.
CDL Practice Question #246
Category: Hazmat
Why this question matters
This question is one of 68 in our Hazmat bank. The reasoning above comes directly from the AAMVA CDL Manual, the source document used by every U.S. state DMV. Memorizing the underlying rule — not just the letter answer — is what separates passing on the first attempt from a return trip and another fee.