Hazardous Materials
Hazardous Materials
This domain tests hazard classes, shipping papers, placards, parking, and railroad-crossing rules. A hazardous materials endorsement is required, and the questions often turn on thresholds.
Classes and paperwork
The nine classes run from 1 (explosives) through 9 (miscellaneous). Shipping papers must describe the material, show the hazard class, and include a 24-hour emergency response telephone number. Keep the papers within reach while driving.
Placards
Placards warn others about the load. Some materials require placards in any amount; others require them at 1,001 pounds or more. A mixed load of Table 2 materials may use the DANGEROUS placard when the aggregate reaches the threshold. Placards must be readable from the direction of approach.
Driving and parking
Avoid smoking and open flames. Park away from people, bridges, tunnels, and congested areas. A placarded load must stop before a railroad crossing, check both directions, and cross only when clear.
Worked example
A truck carries 1,200 pounds of a Table 2 flammable liquid. Because the amount is at least 1,001 pounds, the vehicle needs the proper placard. If the same truck carried 900 pounds, it would generally not need that Table 2 placard, though other rules or local requirements could still apply.
Traps that cost marks
- Applying the 1,001-pound rule to every hazard class.
- Forgetting the emergency response telephone number.
- Parking a placarded load near a bridge or tunnel.
- Rolling through a railroad crossing with a placarded load.