When transporting hazardous materials, how do shippers correctly label their cargo? There are numerous classifications for a wide range of materials that are classified as hazardous or dangerous for a number of reasons, including explosiveness, causticness, and flammability. The class 3 flammable liquids class contains liquids with flash points of no more than 60.5 degrees Celsius or 141 degrees Fahrenheit. It also contains molten materials in their liquid phase with flash points that are no greater than 37.8 degrees Celsius or 100 degrees Fahrenheit. Because there are numerous products and materials that fit into this class, understanding how to properly label and transport them is extremely important. Here are a few things you need to know about the class 3 flammable liquid class.

There Are Exceptions to the General Rules

While the guidelines above lay out the general requirements for a substance to be considered a class 3 flammable liquid, there are a few exceptions. Any liquid that meets one of the definitions outlined in 49CFR 173.115 and any mixtures containing at least one component that makes up at least 99% of the total volume of the mixture and has a flash point of 60.5 degrees Celsius (141 degrees Fahrenheit) or higher are also categorized as class 3 flammable liquids.

According to ISO 2592, any liquid with a flash point greater than 35 degrees Celsius (95 degrees Fahrenheit) that has a fire point greater than 100 degrees Celsius (212 degrees Fahrenheit) falls into the category as well. Liquids with flash points greater than 35 degrees Celsius (95 degrees Fahrenheit) that are in water-miscible solutions and are at least 90% water also fall into this category.

Common Examples of Class 3 Flammable Liquids

Many of the products that we use on a regular basis are classified as class 3 flammable liquids. Gasoline and items that contain gasoline or gasoline fumes are some of the most common examples. Other common types of class 3 flammable liquids include rubbing alcohol, witch hazel, paint and paint-related materials, acetone and cigarette lighters containing butane.

Transporting Class 3 Flammable Liquids

The Department of Transportation (DOT) has strict guidelines for shippers involved in the transport of hazardous materials. Class 3 flammable liquids are one of the most commonly transported dangerous goods worldwide, so it is essential for shippers to understand how to do so safely and in accordance with the law.

Only approved portable tanks and containers may be used to store and transport class 3 flammable liquids. Portable tanks must include provisions for emergency vents that can be used to decrease internal pressure under fire exposure conditions. They must also have at least one pressure-activated vent.

Small containers holding less than 8 gallons of flammable liquid and with a weight less than 440 pounds can be transported by anyone who has undergone general hazmat training. The shipment must include MSDS sheets and must be appropriately labeled as “Gasoline” or “Flammable Liquid.”

When transporting larger quantities of flammable liquids, the requirements of the Department of Transportation are much stricter. While the only documentation required for certain small shipments are MSDS sheets, larger shipments must include an emergency response guide and hazmat bill of lading. Drivers who transport more than 119 gallons or more than 1,001 pounds of class 3 dangerous goods must also have a commercial driver’s license, or CDL. Extensive driver training is also highly recommended for those who carry large amounts.

Shippers who transport containers that hold less than 8 gallons and weigh more than 440 pounds but less than 1,001 pounds and containers that hold between 8 and 119 gallons and weigh less than 1,001 pounds must complete emergency response guide training as well as HM-126F training.

Lastly, all shipments of class 3 flammable liquids must be labeled appropriately. Class 3 flammable liquid labels should be affixed to all small containers to let anyone handling them know that the materials contained within are dangerous. Dangerous Good placards are required by 49 CFR 172.500 as well as the International Maritime Organization. Such placards must be affixed to highway, rail and ocean containers. They are generally made from fade- and water-resistant vinyl to ensure longevity and to prevent them from falling off during transit.


Many of the products we use in our everyday lives are classified as class 3 flammable liquids. As such, these materials are frequently transported by sea, rail and roadway. Understanding these liquids and the requirements for shipping them will help your company better comply with DOT regulations and ensure the safety of your staff as well as the general public.