There are nine different classes of hazardous materials. A class reflects the risks associated with a type of material.

Cylinders and drums are often used to contain hazardous materials. Be sure to take the proper precautions if transporting a cargo of hazardous materials.

A material's ID number must appear on its accompanying shipping paper as well as on its packaging. It must also appear on cargo tanks and other bulk packaging.

Column 2 of the Hazardous Materials Table lists the proper shipping names and descriptions of regulated materials.

When required, hazardous materials placards must be placed on the front, rear, and both sides of a vehicle.

On hazardous materials shipping papers, the identification number, shipping name, and hazard class must not be abbreviated, unless specifically authorized in the hazardous materials regulations.

When a vehicle is required to have hazardous materials placards, at least four identical placards must be displayed. These placards must be placed on the front, back, and both sides of the vehicle.

If a hazardous materials label will not fit on a package, it may be placed on a tag that is securely attached to the package.

Some radioactive materials are required to be accompanied by a transport index. A transport index is a number that indicates how much control the material will require during transport. The total transport index of all cargo in a single vehicle may not exceed 50.

Always set the parking brake before loading or unloading hazardous materials.When loading or unloading containers of hazardous materials, you should not use hooks, or any other tools that could damage containers or packaging. Hazardous materials should be kept away from heat sources.

All drivers must be trained in the security risks of hazardous materials transportation. This training must include how to recognize and respond to possible security threats. Hazardous materials employees must be trained and tested at least once every three years.

While the manual includes all of the information required to pass the hazardous materials knowledge test, you should consider reading the manual as only the first step to learning about the topic. You can learn more by reading and understanding the federal and state rules about the transportation of hazardous materials, as well as by attending hazardous materials training courses.

Parts of a vehicle that have been exposed to corrosive liquids must be thoroughly washed with water.

When a shipper packages hazardous materials, they are certifying that the package has been prepared in accordance with its applicable rules.

When marking hazardous materials in an "HM" column on a shipping paper, the letters "RQ" may be used instead of an "X" if a reportable quantity of the material must be identified.

One clue that a shipment may contain hazardous materials is that the shipper is in a line of business that involves such materials. Examples include paint dealers; chemical suppliers; scientific supply houses; pest control businesses; agricultural supply firms; and dealers in explosives, munitions, or fireworks.

Due to the risks involved, government on federal, state, and local levels may impose regulations on the transportation of hazardous materials. These regulations exist to protect the driver, others near the vehicle, and the environment.

To drive a vehicle of any size that is used to transport hazardous materials, you must have a CDL with a hazardous materials endorsement.

A vehicle carrying hazardous materials must be appropriately placarded to be driven. An improperly placarded vehicle may only be driven if necessary to protect life or property in an emergency.

A vehicle that lacks the proper placards for any hazardous materials on board may not be driven, except as necessary to protect life and property in an emergency.

Many hazardous materials classified as poisonous are also flammable.

Always turn the engine off before refueling a vehicle carrying hazardous materials. Someone must always be at the nozzle controlling the fuel flow.

Unless your engine runs a pump for product transfer, turn it off when loading or unloading a compressed gas tank. If you do use your engine to run a pump, you should turn the engine off after the product transfer but before unhooking the hoses.

When hazardous materials placards are required, they must be placed on all four sides of the transporting vehicle.

Keep liquid discharge valves on a compressed gas tank closed, except when loading and unloading.

When transporting hazardous materials, shipping papers should be kept in a pouch in the driver's side door, or in another location where the driver is able to easily reach them while their seat belt is fastened. The papers must be easily visible to anyone who is entering the cab.

Among other information, shipping papers must include a description of the specific hazardous materials being transported.

If you discover a cargo leak while transporting hazardous materials, use the shipping papers, label, or package location to identify which materials are involved. Do not try to touch or smell the leaking materials to determine what they are because doing so could result in injury or death.

Shippers must place diamond-shaped hazard warning labels on most packages of hazardous materials. If the label won't fit on the package, it can be placed on a tag that is securely attached to the package.

Shippers of hazardous materials must retain a copy or electronic image of the associated shipping papers for at least two years from the date that the material is accepted by the initial carrier. For hazardous waste, this increases to three years.