Awareness-level personnel should become familiar with the ERG prior to an incident occurring. Following are a few important notes when using the ERG.

• If you are unable to identify the UN ID number, do not know the name of the material, do not see a placard or label and cannot identify the rail car or road trailer, use Guide 111 in the orange pages until additional information becomes available. Once the name of the material or accurate UN ID number is identified, redo the flowchart
• A guide number supplemented with the letter “P” next to it indicates that the material may undergo violent polymerization if subjected to heat or contamination
• If you see an explosive placard or label, you will use the orange pages Guides. For Divisions 1.1, 1.2, 1.3, or 1.5, use Guide 112. For Divisions 1.4 or 1.6, use Guide 114