Aviation - Class 7 Distance Requirements

The Transport Index (TI) is placed on the label of most radioactive packages to indicate to the carrier the degree of control that must be exercised during transportation. The TI is derived from a radiation reading conducted one meter from the package containing radioactive materials. The total TI is the sum of the TI on the labels of individual packages. For example, if one HAZMAT contains a TI of 1 and another HAZMAT package contains a TI of 2.5, then the total TI equals 3.5. The TI is used to determine the minimum separation distances from the nearest undeveloped film, passengers, employees, and animals during normal transportation.

Separation distance requirements for packages containing Class 7 radioactive materials differ for both passenger-carrying aircraft and cargo aircraft; special distance requirements are found in §175.701 for passenger-carrying aircraft and §175.702 for cargo aircraft.

However, Class 7 radioactive materials within both passenger-carrying and cargo aircraft labeled RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III, must follow distance requirements prescribed by the chart under §175.706.

For passenger-carrying aircraft, persons involved with the transport of packages containing Class 7 radioactive material must ensure that:

• The minimum separation distances, found under §175.701 (a), between RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III and passengers and crew are followed.
• Overpacks or freight containers labeled RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III must be separated from live animals by a distance of at least 0.5 m (20 inches) for journeys less than 24 hours and 1.0 m (39 inches) for journeys longer than 24 hours.
• If more than one package of Class 7 materials is placed in a passenger-carrying aircraft, the minimum separation distances for these packages must be determined by the sum of the packages (total TI).
• A package labeled RADIOACTIVE YELLOW-II or RADIOACTIVE YELLOW-III must have a pre-designated area established by the aircraft operator.

For cargo aircraft, persons involved with the transport of packages containing Class 7 radioactive materials must ensure that:

• The minimum separation distances, found under §175.702 (ii), between radioactive materials and any areas occupied by persons are followed.
• The total (TI) for all packages does not exceed 50.0 and the packages are in accordance with §175.701 (a).
• If the total TI for all packages does exceed 50, the separation distance between the surfaces of the radioactive materials packages, overpacks, or freight containers is at least 0.5 m (20 inches) for journeys less than 24 hours and 1.0 m (39 inches) for journeys longer than 24 hours.
• The criticality safety index of any single group of packages does not exceed 50.
• Each group of packages is separated from every other group in the aircraft by no less than 6 m (20 feet), measured from the outer surface of each group.

To learn more about Aviation HAZMAT visit our DOT Aviation HAZMAT Online Training web page.