Can Hazmat Change Classes During Transportation?

Posted on 7/31/2025 by Lion Technology Inc.

Materials, hazardous and otherwise, can change states. At different temperatures, water becomes gas, and sand becomes glass.

At room temperature, phosphoric acid is a crystalline solid with a melting point of around 100° F. During transportation, ambient temperatures can range from -40° F to over 200° F. So, it is reasonable that solid phosphoric acid could liquefy, and liquid phosphoric acid can corrode metal packagings and vehicles.

So, hazmat can change classes during transportation, right? Wrong.

Hazmat Changes Characteristics, Not Classes

For some materials, we do not wait until they exhibit the characteristics of a hazardous material to classify them. Solid phosphoric acid powder is a Class 8 corrosive hazardous material because of its potential to liquefy and become corrosive. Believe it or not, the Hazardous Materials Regulations (HMR) already cover this specific issue.

“A liquid, or a solid which may become liquid during transportation, that has a severe corrosion rate on steel or aluminum based on the criteria in 173.137(c)(2) is also a corrosive material.”
[49 CFR 173.136(a)]

Put simply, it is the shipper’s responsibility to classify, name, and package a material as if it will exhibit the most hazardous characteristics possible during transportation.

How to Pack Shapeshifting Hazmat

Learn all the DOT’s rules for classifying, packaging, marking, labeling, and documenting your hazmat shipments in full compliance with the Hazardous Materials Regulations at Lion’s Hazmat Ground Shipper Certification (DOT) Workshop.

Or browse all Lion’s hazmat shipper training at Lion.com/Hazmat.

Tags: hazardous materials, hazmat shipping

Find a Post

Search for:

Compliance Topics

Compliance Archives

Lion's online training is more comprehensive, has better slides, and is a superior training experience than what I would get from other trainers.

Robert Brenner

District Environmental Manager

I really enjoy your workshops. Thank you for such a great program and all the help Lion has provided me over the years!

George Chatman

Hazardous Material Pharmacy Technician

We have a very busy work schedule and using Lion enables us to take the course at our own time. It makes it easy for me to schedule my employees' training.

Timothy Mertes

Hazmat Shipping Professional

This training broke down the regulations in an easy-to-understand manner and made them less overwhelming. I now feel I have the knowledge to make more informed decisions.

Amanda Oswald

Shipping Professional

The instructor was very knowledgeable and provided pertinent information above and beyond the questions that were asked.

Johnny Barton

Logistics Coordinator

The instructor was excellent. They knew all of the material without having to read from a notepad or computer.

Gary Hartzell

Warehouse Supervisor

Convenient; I can train when I want, where I want.

Barry Cook

Hazmat Shipping Professional

The instructor's energy, enthusiasm, and knowledge of the subject make the class a great learning experience!

Brian Martinez

Warehouse Operator

I really enjoyed this training. Even after years on both sides of the comprehension coin, I find myself still learning! The quality of the delivery exceeded much of the training I have received in the past.

Neil Ozonur

Safety Officer

If I need thorough training or updating, I always use Lion. Lion is always the best in both instruction and materials.

Bryce Parker

EHS Manager

Download Our Latest Whitepaper

Ace hazmat inspections. Protect personnel. Defend against civil and criminal penalties. How? See the self-audit "best practices" for hazardous materials shippers.

Download

By submitting your phone number, you agree to receive recurring marketing and training text messages. Consent to receive text messages is not required for any purchases. Text STOP at any time to cancel. Message and data rates may apply. View our Terms & Conditions and Privacy Policy.