Many hazardous materials classified as poisonous are also flammable.

While the manual contains all of the information needed to pass the written exam for a hazardous materials endorsement, it does not contain all of the information necessary to do the job safely. You can learn more by attending hazardous materials training courses.

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

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.

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.

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

To determine which hazardous materials placards to use, you must know the hazard class of the materials; the amount of hazardous materials being shipped; and the total weight of all classes of hazardous materials in the vehicle.

If a substance is being transported in a reportable quantity, the shipper must display the letters "RQ" on the shipping paper and package.

Shippers package hazardous materials in a way that is meant to completely contain the materials. Vehicles should be placarded to communicate the risk of the cargo.

If your vehicle breaks down on the road while you are transporting explosive materials, you must warn other drivers. Put out warning signals like reflective triangles or electric lights if you are carrying Division 1.1, 1.2, or 1.3 explosives. Do the same if you are driving a tank used to transport Class 3 flammable liquids or Division 2.1 flammable gases, even if the tank is empty. If transporting flammable materials, do not use warning signals that could cause your cargo to catch fire.

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 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.

If you discover a leak in a cargo of hazardous materials, identify the materials in question by using the shipping papers, labels, or package location. Do not touch the leaking material.

At a minimum, emergency response information must include the basic descriptions and technical names of the materials being transported; immediate hazards to health; risks of fire or explosion; immediate precautions to be taken in the event of an accident or incident; immediate methods for handling fires; initial methods for handling spills or leaks in the absence of fires; and preliminary first aid measures.

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

You must have a commercial driver license with a hazardous materials endorsement before driving a vehicle of any size that is used to transport hazardous materials, even if the vehicle is not transporting hazardous materials at the time of operation.

Fighting a hazardous materials fire requires specialized training and equipment. Unless you possess these yourself, it is best to let emergency personnel deal with the fire.

When experiencing a cargo fire, it may be a bad idea to open the doors to the trailer. Doing so allows oxygen to enter the area, potentially causing the fire to flare up and expand.

Packages that contain liquid containers must have orientation markers. Arrows displayed on the box should be pointing in the correct upright direction.

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.

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.

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.

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

Hazardous materials warning placards are diamond-shaped.

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.

It is a good idea to compare a shipping paper to the applicable package markings and labels. Ensure that the shipper has included the correct basic description on the shipping paper and that it matches markings and labels.

Flammable liquids should not be transferred from one vehicle to another on a public roadway, unless being moved due to an emergency. Always warn others of the hazards presented by the materials.

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.

Nitric acid should not be stacked above any other product. Containers of nitric acid may be stacked, but no higher than two containers high.

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