A compressed gas meeting the defining criteria of 49 CFR 173.115 must comply with the Hazardous Materials Regulations (HMR) of the USDOT/PHMSA when transported, or offered for transport, in commerce. However, there are some exceptions from full regulation for certain compressed gases.  These potentially excepted compressed gases are identified at §173.307.

The following materials are not subject to the Hazardous Materials Regulations of USDOT/PHMSA:

• Carbonated beverages.
• Tires when inflated to pressures not greater than their rated inflation pressures.
  • For transportation by air, tires and tire assemblies must meet the conditions in §175.8(b)(4).
• Balls used for sports.
• Refrigerating machines, including the following:
  • Dehumidifiers,
  • Air conditioners, and;
  • Components of dehumidifiers and air conditioners (e.g., precharged tubing).

If contains…

• • 12 kg (25 lb) or less of a non-flammable, non-toxic gas, or;
  • 12 L (3 gal) or less of ammonia solution (UN2672), or;
  • 12 kg (25 lb) or less of a flammable, non-toxic gas (unless transported by air), or;
  • 20 kg (44 lb) or less of a Group A1 refrigerant specified in ANSI/ASHRAE Standard 15 (unless transported by air or vessel), or;
  • 100 g (4 oz) or less of a flammable, non-toxic liquefied gas.

• Manufactured articles or apparatuses, other than light bulbs, each containing not more than 100 mg (0.0035 oz) of inert gas and packaged so that the quantity of inert gas per package doe not exceed 1 g (0.035 oz).
• Light bulbs (lamps) as described at §173.11.

If the material you transport or offer for transport is one of the above, then congratulations! The transport of that material is not subject to the HMR. If, however, you are the offeror (i.e., shipper) or transporter of a hazardous material, then you must comply with all of the regulations of the USDOT/PHMSA for its classification, packaging, hazard communication, and more. Contact me your questions about the transportation of hazardous materials by highway, rail, vessel, or air.