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Haz-Mat Survival Tips -Beyond The Rule Of Thumb
Survival Tip 2 - Interpreting Highway Transportation Placards
By Steven De Lisi
During an early morning rush hour, you respond to a report of a vehicle accident involving a tractor trailer. Upon arrival, you discover the vehicle has overturned down an embankment. The driver has managed to escape from the vehicle, but may have suffered a head injury since he has no recollection of events just prior to the incident or what may be loaded on the trailer. Any attempt to retrieve the shipping papers from the truck cab is too dangerous at this time, but using binoculars, you notice a steady leak of a clear liquid exiting from the rear of the trailer. You do not see any placards on the trailer. Since the vehicle is not placarded, is it safe to conclude that the liquid is NOT a hazardous material?
During another incident, you respond to a reported vehicle fire involving an 18' box truck. Upon arrival, you find the cab of the truck fully involved, with fire quickly spreading to the cargo box. The truck displays the "dangerous" placard. Just what does this placard indicate?
First responders should always remember that placards function primarily as an information system designed to indicate a material's assigned hazard class. While knowing the exact name of hazardous materials involved in a highway transportation incident is best, knowing at least the hazard class will still enable first responders to make better informed decisions. Information available from placards usually includes the following:
- Background color(s)
- Hazard class name (displayed in the center)
- Hazard class number (single-digit number displayed in the lower corner)
- Symbol (displayed in the upper corner)
Placards are normally affixed to the front, rear, and both sides of transport vehicles such as closed vans, flatbeds, and cargo tanks. The required placarding for the front of a motor vehicle may be on the front of a truck or tractor instead of, or in addition to, a placard on the front of the cargo body to which the truck or tractor is attached.
When transport vehicles such as closed vans or flatbed trucks display placards, any one of the following situations could exist:
- Any quantity of a material that meets the definitional criteria of a hazard class found in Table 1 of 49 CFR. These include materials that are categorized as explosive, dangerous when wet, and radioactive, along with certain types of organic peroxides. There are also some poisonous materials that can present first responders with inhalation hazards.
- 1,001 pounds or more of a material that meets the definitional criteria of a hazard class found in Table 2 of 49 CFR. These include materials categorized as corrosive, flammable materials in the form of solids, liquids, or gases, as well as oxidizers and some types of explosives.
- There could also be lesser amounts of materials found in Table 2, since regulations allow placards to be used if less than 1001 pounds of these materials are being transported.
- Display of the "dangerous" placard likely indicates a mixed load of materials from Table 2.
- Display of a four-digit identification number either in the center of a placard (in lieu of the hazard class name) or on orange panels located near placards on a closed van or flatbed may indicate the presence of materials shipped in large packages or a large quantity of small packages.
When transport vehicles such as closed vans and flatbed trucks do not display a placard, the following situations could exist:
When transport vehicles such as highway cargo tanks display placards, usually the hazard class name displayed in the center of a placard is replaced by a four-digit identification number for the material being transported. When first responders see this number displayed on a highway cargo tank, the following situations could exist:
- The presence of only the material assigned the displayed four-digit identification number.
- When a cargo tank with multiple compartments contains "different liquid petroleum distillate fuels,"(such as gasoline and diesel fuel) the identification number for the distillate having the lowest flash point (and thus the more dangerous commodity) may be displayed instead of the individual number for each material.
- Placards usually cannot be removed from a cargo tank unless it is "sufficiently clean of residue and purged of vapors to remove any potential hazard." As a result, it may be difficult during the initial phase of an incident to determine the quantity of material loaded in a cargo tank.
For additional study, first responders can refer to the latest edition of the Emergency Response Guidebook for full color diagrams of placards commonly found on highway transport vehicles.
Match the following placard background colors, symbols, and hazard class numbers with the appropriate hazard class. When you're done, use the latest edition of the Emergency Response Guidebook to check your answers.
1. Match the following background colors found on placards with the hazard class.
| Blue | Non-Flammable Gases |
| Yellow | Corrosive |
| Orange | Dangerous When Wet |
| Red / White vertical stripes | Spontaneously Combustible |
| White over Black | Oxidizer / Organic Peroxide |
| Green | Explosive |
| White over Red | Flammable Solids |
2. Match the following symbols found on placards with the hazard class.
| Cylinder | Flammable solid, liquid, gas |
| Flame | Poison |
| Burning "O" | Nonflammable compressed gas |
| Skull and crossbones | Oxidizer |
3. Match the following hazard class numbers found on placards with the hazard class.
| Explosives | 6 |
| Gases | 8 |
| Flammable liquids | 1 |
| Flammable solids | 9 |
| Oxidizers and organic peroxides | 7 |
| Poisonous materials and infectious substances | 5 |
| Radioactive materials | 3 |
| Corrosive materials | 4 |
| Miscellaneous hazardous materials | 2 |
Steven M. De Lisi is Deputy Chief for the Virginia Air National Guard Fire Rescue located in Henrico County and a 26-year veteran of the fire service. He has served as a company officer for the Newport News (VA) Fire Department and as a regional training manager for the Virginia Department of Fire Programs. He is a certified Hazardous Materials Specialist and previously served with the Virginia Department of Emergency Management in the Technological Hazards Division. De Lisi is currently chairman of the Virginia Fire Chiefs Association's Hazardous Materials Committee and a former member of the National Fire Protection Association's committee on Hazardous Materials Protective Clothing.
