Placards
Class 9 Miscellaneous Placards Explained (Lithium Batteries)
What the black-and-white striped Class 9 placard means, why lithium batteries and dry ice fall here, and the quirky domestic placarding rules.
Lawrence Arya··6 min
Placards
Compatibility Groups for Explosives Explained (the Letter Codes)
What the letter on a Class 1 explosives placard means, how compatibility groups decide what can travel together, and why 1.1D looks the way it does.
Lawrence Arya··5 min
Placards
Dangerous When Wet Placard Explained (Division 4.3)
What the blue dangerous-when-wet placard means, why it is the only blue diamond, which materials carry it, and why it must be placarded in any amount.
Lawrence Arya··5 min
Test prep
DOT Hazmat Roadside Inspections Explained (What They Check)
What a roadside inspection checks on a hazmat load, from placards and papers to securement, and how to be ready so a stop goes smoothly.
Lawrence Arya··5 min
Placards
Elevated Temperature Marking Explained (the HOT Marking)
What the HOT marking means, which elevated-temperature materials require it, and how it differs from a hazard placard. A quick study guide for CDL students.
Lawrence Arya··5 min
Placards
The Emergency Response Guidebook (ERG) Explained
What the ERG is, what its yellow, blue, orange, green, and white sections do, and how a responder uses a UN number to find the right action guide.
Lawrence Arya··6 min
Placards
Flammable vs Combustible Liquid: The Difference (Class 3)
Flammable and combustible liquids are both Class 3 but split on flash point. Here is the dividing line, the placards, and why diesel sits near the edge.
Lawrence Arya··5 min
Test prep
Forbidden Hazardous Materials Explained (49 CFR 173.21)
Some materials are forbidden from transport entirely. Here is what makes a material forbidden, common examples, and why a driver should never accept one.
Lawrence Arya··5 min
Placards
Hazardous Materials Hazard Classes Explained (1 to 9)
A plain-English breakdown of the nine DOT hazard classes, what each one covers, the placard color and symbol that signal it, and how to memorize them.
Lawrence Arya··6 min
Test prep
Hazardous Waste Manifest Explained (Cradle to Grave)
What the Uniform Hazardous Waste Manifest is, why it tracks waste from generator to disposal, and how it works as shipping papers for a driver.
Lawrence Arya··5 min
Test prep
Hazmat Endorsement Disqualifying Offenses (TSA Rules)
Which offenses can block a CDL hazmat endorsement, the difference between permanent and interim disqualifiers, and where the TSA rules live.
Lawrence Arya··5 min
Test prep
Hazmat Fines and Penalties Explained (Why Compliance Matters)
What happens when hazmat rules are broken: civil and criminal penalties, out-of-service orders, and why the consequences are designed to be serious.
Lawrence Arya··5 min