What’s on the Truck

Sinclair Gas Mascot going for a Ride

August 9 - We made a quick 2,000 mile trip over 7 days. There wasn’t a lot of time for side trips or interesting photos. We saw thousands of acres of corn, many cows, every size and configuration of hay bale, and more wind turbines than you can imagine. Actually, the passenger gets to see those things. The driver gets to see long sections of asphalt pavement that occasionally run into sections of concrete pavement. All this exciting entertainment occurs along side commercial trucks carrying, something? Often you just can’t tell what they’re carrying. If it is a Walmart or FedEx truck you have a pretty good idea what’s on the truck. Sometimes there is a tarp over a strange shape. If you had kids in the car it might be a fun guessing game for them but you have to start the game knowing you are unlikely to ever know the true answer. It took us a while to figure out why someone was traveling with a dinosaur. And we could clearly see it was a dinosaur. If it’s a tanker truck carrying hazardous material, it’s a different story. You can look up what’s on the truck. 

You may have seen the diamond shaped signs on the sides or back of some trucks. These signs are hazmat placards. Often there will be several, one of which has a four digit number between 0004 and 3534. These numbers are UN numbers that are assigned by a team of shipping experts at the United Nations. This ensures that, the same set of numbers will be used everywhere to identify what is in a container. Additionally, the placards provide shippers and first responders with information on what can or shouldn’t be shipped together and what dangers the material may present in an emergency. Consider an accident where a tank is leaking an unknown substance. First responders can’t go over to take a sample then wait for the lab analysis to come back. The placards allow first responders to determine what is in the container from a distance then decide the correct course of action.

The truck in the photo above says “Liquefied Petroleum Gas” which makes the placard above it redundant but its the photo I have for example purposes. Let’s consider the diamond-shaped sign above it. That sign says 1075 which also means LPG. You’ll see that the sign also has a red background with the number 2. Red means flammable and if you didn’t know that, there is a helpful picture of flames. But the number 2 means it’s a gas. That way in an emergency, if you couldn’t look up 1075, you would still be able to tell the truck was transporting a flammable gas.

Not all hazardous materials are flammable so the classification system has 9 categories with background colors for additional information. Those 9 classes are:

1 Explosives (orange)

2 Gases (Flammable, Non-Flammable, Inhalation Hazards) (red, green, black and white, or yellow)

3 Liquids (Combustible, Flammable) (red)

4 Solids (Flammable, Dangerous when Wet, Spontaneously Combustible) (red and white, blue, white top / red bottom)

5 Oxidizers, Organic Peroxides (yellow, red top / yellow bottom)

6 Poisons, Inhalation Hazards (white with black writing)

7 Radioactive (yellow top / white bottom)

8 Corrosives (black and white)

9 Miscellaneous Hazards (black and white strip top / white bottom)

There are colored background for each of the 9 categories as indicated above. If the gas in the truck above had been non-flammable, something like carbon dioxide, 1013, then the placard would have a green background similar to the one shown below.

The most specific information however is the UN number. The sign I have seen most often is 1203 meaning gasoline. But is some areas where a specific industry uses or produces a hazardous material other UN numbers are common. In parts of Colorado we see more trucks with 1267 placards than passenger cars. The 1267 placards are for petroleum crude oil.

Red for Flammable, 3 for Liquid

If you want to know more about UN numbers and hazmat placards SafeRack and Hazmattool both are good sources that go into much more detail. If your traveling and wonder what is in that truck next to you and you happen to have an internet connection, you can easily look up a UN number on a reference site like Wikipedia’s list of UN number or simply Google “UN” followed by the number.

I first became aware of, and therefore curious about, UN numbers when a coworker retired and handed be a pocket size book of the numbers. Before that I had only seen a truck with sign, which I ignored. I had never stopped to consider what it was telling me. Now I want to know if I’m traveling at 75 miles an hour beside a tank of 2480!

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