It's determined by weight. Gasoline is Hazard Class 3, which requires placards to be displayed if more than 1,000 lbs. of it is being transported. One gallon of petrol weighs between 5.8 and 6.5 lbs, so you'd be looking at 153 to gallons (roughly) before placards had to be displayed.
Manifest
Gasoline falls under the class of petroleum products, specifically within the category of flammable liquids. It is classified as a hazardous material due to its potential for combustion and fire hazards.
The Air Force Interservice Manual 24-204 (AFMAN 24-204) definition of Hazardous Material is "A substance or material that is capable of posing an unreasonable risk to health, safety, and property when transported and has been so designated by this manual."
Hazardous material ceases to be hazardous when it is destroyed, sufficiently diluted in nonhazardous material, it is chemically changed into a nonhazardous material or incorporated into an object that immobilizes it and renders it unable to be hazardous.
The DOD Form used to document the transportation of hazardous material by military vehicle is the DD Form 626, titled "Motor Vehicle Inspection." This form ensures that vehicles transporting hazardous materials meet safety requirements and are in compliance with regulations. It includes details about the vehicle, the hazardous materials being transported, and any safety measures taken.
which hazardous material can enter the body
a. a hazardous material is exposed to fire.
In the United Kingdom, fire extinguishers are not considered as hazardous material for transportation by road. Fire extinguishers are considered hazmat for transportation by road and sea and should be accompanied with Dangerous Goods Note and Material Safety Data Sheets. Certain types of fire extinguishers may contain placard-required amounts of hazardous materials, including pressurized CO2 or nitrogen, liquids such as carbon tetrachloride, among other things. Therefore, the answer to the question would depend upon the specific type and quantity of extinguishers being transported.
Polystyrene is not a hazardous material (dangerous good) in transportation. However, in circumstances where a fire might be a problem, polystyrene, which can readily and rapidly burn, can be a very hazardous material.
When receiving a shipment of hazardous materials, the first thing to do is to determine the nature of the hazardous material and then inspect it to ensure there are no leaks.
While there are reams of federal paperwork and regulations on this subject, the individual states ARE empowered to be even more strict in their regulation of material stored, used or transported WITHIN their state.
a hazardous material