Dangerous Goods Class 7: Radioactive Materials

After Class 6, there’s the dangerous goods Class 7 featuring radioactive materials, which are comprised of unstable atoms capable of transforming their structure off the cuff. Over some time, these changes happen in a random fashion. With no subdivisions in the class, read on to find out what goods belong here and how to ship them correctly.

Substances For Radioactive Materials

In general, substances categorized as the radioactive materials in the dangerous goods Class 7 include spent nuclear fuel and radioactive metals like cobalt, plutonium, and uranium. There are also scientific isotopes used for x-ray imaging and therapy, as well as smoke detectors mostly consisting of americium radionuclides.

These are the commonly transported goods and materials in Class 7:

1. Enriched uranium
2. Depleted uranium
3. Radioactive ores
4. Uranium hexafluoride
5. Density gauges
6. Mixed fission products
7. Yellowcake
8. Surface contaminated objects

Adding into the list above is radionuclides and isotopes:

1. Cesium
2. Iridium
3. Americium
4. Plutonium
5. Radium
6. Thorium
7. Uranium

These substances need to be carefully handled and regulated since they tend to emit invisible ionizing radiation that is harmful to humans once exposed in a large dose or for a specific period.

Shipping Rules for Radioactive Materials

When we’re talking in the context of transportation, the radioactive materials in the dangerous goods Class 7 are described as “any substance with a specific activity greater than 0.002 microcuries per gram” by the U.S. Nuclear Regulatory Commission (NRC).

Considering that radioactive materials already pose a danger even when in small quantities, the shipping rules always starts from properly advised packaging. There’s a specific degree of care to consider, and each substance has different regulations to overlook. One guide you can look up to is the USDOT Hazmat Tables.

However, packages for the radioactive materials in the dangerous goods Class 7 are pretty safe to handle and transport whenever done accordingly. The bottom line lies in the packaging itself, as long as it’s the UN-compliant hazmat packaging.

Besides being the shield, the packaging can alert the shipping personnel through either the 4G or 4GV hazmat boxes.  Moreover, keeping the dose of ionizing radiation moderate also helps in preventing any health hazard for transport workers. 

Also consider placing vermiculite, a hydrous phyllosilicate mineral commonly used in gardening and building. Besides filling any void in the packages, this mineral is non-reactiveand helps absorb moisture.

Categorizing Radioactive Materials

Meanwhile, a five-string packaging method is devised based on the radioactivity levels inside the package:

·       Excepted Packaging

This packaging is for substances posing surface radiation level less than 5 m Sv/hour and applies the U.S. government’s 49 CFR 173.421 packaging criteria.

·       Industrial Packaging

This packaging is for low-level radioactive materials and applies 49 CFR 173.411 packaging criteria.

·       Type A Quantity Packaging

This packaging is for low-to-medium radioactive substances and applies 49 CFR 173.412 packaging standards.

·       Type B Quantity Packaging

This packaging is for medium-to-high radioactive materials and must meet 49 CFR 173.413 packaging standards.

·       Highway Route Controlled Quantity

This packaging is for substances with the highest levels of radioactivity and only aided by military organizations and government.