Special hazards: explosives, radioactive, poisonous, and corrosive materials
Explosives (Class 1)
Divisions run 1.1 mass explosion, 1.2 projection, 1.3 fire with minor blast, 1.4 minor explosion, 1.5 very insensitive, 1.6 extremely insensitive. Compatibility groups (A–G and S) further limit what rides together. Placards are required for any quantity of 1.1, 1.2, and 1.3; 1.4, 1.5, and 1.6 follow the 1,001-lb Table 2 rule. No smoking anywhere near the vehicle, and observe the 5-foot and 300-foot parking limits.
Radioactive (Class 7)
Labels run White-I (lowest surface reading), Yellow-II, and Yellow-III (highest); Yellow-II and Yellow-III packages carry a transport index and require placards for any quantity. Use time, distance, and shielding - doubling distance sharply cuts dose. Packages travel in closed or exclusive-use vehicles, never with food, and you inspect for damage, leakage, or a broken seal before signing.
Poisonous and inhalation hazards (Class 6.1)
Materials in Hazard Zones A–D are toxic by inhalation. They are never loaded with food or feed and are placarded for any quantity. Never open a package or smell the product to identify it; stay upwind; a dust mask gives no protection against most toxic vapors.
Corrosive (Class 8)
Acids and bases burn skin and destroy metal, and some react violently with water. Check closures and look for staining or fumes before loading, keep cyanides away from acids, and flush exposed skin with water for at least 15 minutes.
Worked example
A pickup includes a case labeled Radioactive Yellow-III, transport index 2.5. You must placard RADIOACTIVE, keep it out of any food load, secure it as far from the cab as practical, and verify the package is undamaged before signing.
Traps that cost marks
Loading Class 6.1 with a food shipment; confusing White-I with Yellow-III; assuming all corrosives behave alike when some are water-reactive.