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.

Shippers of certain kinds of hazardous materials are required to display diamond-shaped warning signs, known as placards, on any transporting vehicles. Shippers are required to provide applicable placards, labels, shipping papers, and emergency response information.

A placard must be placed at least three inches away from any other markings. The placard should be kept clear of attachments or devices, such as doors and ladders. Placards should always be placed against a background of a contrasting color.

If you are experiencing a truck fire, you should not attempt to open trailer doors without first feeling the doors to see if they are hot. If the doors are hot, there may be a cargo fire. Leave the doors closed if there is a cargo fire.

You must examine each tire on a motor vehicle at the beginning of each trip. The only effective way to check tire pressure is by using a tire pressure gauge.

If the words "Inhalation Hazard" appear on the shipping paper or package, you must display the "Poison Inhalation Hazard" or "Poison Gas" placards, as appropriate.

If a shipping paper describes both hazardous and non-hazardous materials, the hazardous materials must be distinguished in one of three ways. They must be entered first on the shipping paper, highlighted in a contrasting color, or properly marked with an "X" in a column titled "HM."

If you discover that a cargo of hazardous materials is leaking from your vehicle, you should park the vehicle as soon as possible. The longer you continue driving, the longer the trail of contamination becomes. While this creates potential danger and harm to others, it also increases clean-up expenses.

In general, vehicles carrying hazardous materials are required to display diamond-shaped warning signs on all four sides. These warning signs are called "placards."

On a compressed gas tank, liquid discharge valves must always be kept closed, except during loading and unloading.

When carrying Division 1.1, 1.2, or 1.3 explosives, you should not park within 300 feet of a bridge, tunnel, or building, unless you are parking for a short period of time while performing an operational necessity, like refueling.

You should use a floor lining when transporting Division 1.1, 1.2, or 1.3 materials. The floors must be tight and the liner must be made from either non-metallic material or non-ferrous metal. Non-ferrous metals are any metals that do not contain iron or iron alloys.

When transporting hazardous materials, you may leave your vehicle unattended in a safe haven. A safe haven is a location that has been approved for parking unattended vehicles that are loaded with explosives.

You should not smoke within 25 feet of a placarded cargo tank used to transport materials that are categorized as Class 3 (flammable liquids) or Division 2.1 (gases). Do not smoke or carry a lit cigar, pipe, or cigarette near a vehicle containing flammable or explosive materials.

Always protect containers of hazardous materials. When loading hazardous materials, never use equipment that could damage containers or packaging, such as hooks.

If a cargo of hazardous materials begins to leak, do not move your vehicle any more than safety requires. If you continue to drive, an even larger area will become contaminated. Instead, you should park your vehicle, secure it, stay with the vehicle, and contact the proper emergency personnel. If you do not have access to a phone, you should send someone else to get help.

Before loading or unloading a tank with flammable liquids, you should turn off the engine, unless running the engine is necessary to operate a pump. Ground the tank before opening the filling hole and maintain the ground until after closing the filling hole.

If you need to refuel a vehicle carrying hazardous materials, you must first turn off the engine. While refueling, someone must be at the nozzle and controlling the fuel flow at all times.

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.

When applying for an original or renewed HazMat endorsement, you must undergo a federal security threat assessment done by the Transportation Security Administration (TSA).

Packaging can be an indicator of whether or not materials are hazardous. Cylinders and drums are often used to hold and transport hazardous materials.

If transporting Division 1.1, 1.2, or 1.3 explosives, you must follow a written route plan. Whenever placarded, avoid heavily populated areas, crowds, tunnels, narrow streets, and alleys. Be sure to research any restrictions that may apply to the routes you plan to take.

Containers of hazardous materials should be braced so they will not fall, slide, or bounce around during transportation.

A placarded vehicle must have at least four identical placards: one on the front, one on the rear, and one on each side of the vehicle.

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.

A hazardous material will be placed into one of nine classes to explain the type of risks associated with the material.

Shippers of hazardous materials are required to include an emergency response telephone number on shipping papers.

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.

When carrying Division 1.1, 1.2, or 1.3 explosives, do not park within 300 feet of a bridge, tunnel, or building; a place where people gather; or an open fire.

Shippers of hazardous materials are required to warn drivers and others about the risks of the materials by putting hazard warning labels on packages, putting placards on the transporting vehicles, and providing proper shipping papers and emergency response information.