Placards
Hazmat Placard Colors Explained for CDL Students
What each Hazmat placard color signals, why color is the fastest first clue, and where color alone is not enough.
Lawrence Arya··6 min read
Featured
Recent
Test prep
Bulk vs Non-Bulk Packaging Explained (Hazmat Basics)
What separates bulk from non-bulk hazmat packaging, the capacity thresholds that define each, and why the difference changes placarding and markings.
Lawrence Arya··5 min
Test prep
Cargo Tank Types Explained (DOT406, 407, 412, MC331, MC338)
The main cargo tank types and what each one hauls, from flammable liquids to high-pressure gases. A CDL study guide to recognizing tankers.
Lawrence Arya··5 min
Test prep
CDL Hazmat Endorsement Requirements: What to Expect
A study-focused rundown of what the CDL hazmat (H) endorsement involves: the knowledge test, the TSA security threat assessment, eligibility, fees, and renewal.
Lawrence Arya··6 min
Study tips
CDL Hazmat Test Anxiety: Practical Tips That Help
Nervous about the CDL hazmat test? Practical, no-nonsense ways to lower test anxiety before and during the exam, from preparation to breathing to question strategy.
Lawrence Arya··5 min
Placards
Class 1 Explosives Placards Explained (Divisions 1.1 to 1.6)
What the orange Class 1 explosives placard means, the six divisions from 1.1 to 1.6, compatibility groups, and which ones must be placarded in any amount.
Lawrence Arya··6 min
Placards
Class 2 Gas Placards Explained (Divisions 2.1, 2.2, 2.3)
Class 2 gases come in three colors for three divisions: red flammable gas, green non-flammable gas, and white toxic gas. Here is how to tell them apart.
Lawrence Arya··6 min
Placards
Class 3 Flammable Liquid Placards Explained (the Red Diamond)
The red Class 3 placard is the one drivers see most. Here is what it means, the common materials behind it, and the UN numbers worth recognizing.
Lawrence Arya··5 min
Placards
Class 4 Flammable Solids Placards Explained (4.1, 4.2, 4.3)
Class 4 has three very different divisions: flammable solids, spontaneously combustible materials, and dangerous-when-wet. Here is how to tell the placards apart.
Lawrence Arya··6 min
Placards
Class 5 Placards: Oxidizer vs Organic Peroxide (5.1, 5.2)
Class 5 has two yellow-leaning divisions that students mix up. Here is how oxidizers (5.1) and organic peroxides (5.2) differ and how to read each placard.
Lawrence Arya··6 min
