Driver (CDL) - Loading and Unloading Class 2 Gases

Do not load cylinders containing Class 2 - Gases materials onto a motor vehicle that does not have a flat floor or platform. If the motor vehicle floor or platform is not flat, the cylinder must be:

• Securely restrained in an upright position
• Loaded into a rack or packaged in a box or crate attached to the motor vehicle
• Protected from movement or ejection during normal transportation

If there is a cylinder containing Division 2.1 gas onboard the motor vehicle, a pressure relief device, when installed, must be in communication with the vapor space of the cylinder. Turn off engines during loading and unloading, unless the engine is being used for the operation of the transfer pump of the vehicle. For each shipment of Division 2.1 materials, the driver must make a written record of the cargo tank pressure at the start of each trip, immediately before and after manual venting, at least once every five hours, and at the destination point.

Vehicles carrying a specification DOT-4L cylinder containing hydrogen, cryogenic liquid can only be transported under the following regulations:

• The vehicle must have an open body with a suitable rack that holds the cylinder upright when subjected to an acceleration of 2 "g."
• The combined total of the hydrogen venting rates must not exceed 60 SCF per hour.
• Highway transportation must be limited to private and contract carriage and to direct movement from point of origin to destination.
• The vehicle must not enter a tunnel.

Chlorine cargo tank motor vehicles must not be moved when loading and unloading connections are attached to the vehicle, nor may it be left without the power unit attached, unless means are provided to prevent motion. Chlorine cargo tank motor vehicles may only be shipped when equipped with the following:

• A gas mask approved by the National Institute of Occupational Safety and Health Pittsburgh Research Center
• An emergency kit for controlling leaks

Regularly check a Division 2.1 flammable gas that is a cryogenic liquid in a package exceeding 450 L of water capacity, and write a record of the cargo tank pressure and outside temperature at the start of each trip, immediately before and after any manual venting, at least once every five hours, and at the destination point.

Cargo tank motor vehicles must also undergo safety checks by a qualified person before unloading a liquefied compressed gas. This check must be made after pressure in the discharge system has reached equilibrium with the pressure in the cargo tank.

Further cargo tank motor vehicle requirements can be found in §177.840.

To learn more about CDL HAZMAT Transportation visit our DOT Driver (CDL) HAZMAT Transportation Online Training web page.