Class 7 Radioactive Signs – What They Are and Why They Matter

“Class 7 radioactive and fissile dangerous goods signs infographic showing label types and compliance markings.”

Class 7 Radioactive Signs – What They Are and Why They Matter

Radioactive materials are tightly regulated around the world, and for good reason — mishandling them can pose serious risks to people, workplaces, and the environment. That’s why Class 7 Dangerous Goods Signs exist: to clearly identify when radioactive materials are present during transport or storage.

In New Zealand and Australia, using the correct Class 7 signage is a legal requirement under NZS 5433, the HSNO Act, and UN transport regulations. In this guide, we’ll explain the different types of Class 7 signs, when they must be used, and how to stay compliant.

Understanding Class 7 Radioactive Materials

Class 7 dangerous goods include any material that emits ionising radiation. These can be used in a wide range of industries, including:

  • Medical – radiopharmaceuticals for diagnosis and cancer treatment

  • Research – radioactive isotopes for scientific studies

  • Industrial – radiography, gauges, or material testing

  • Energy – uranium and plutonium fuels (though less common in NZ)

Because exposure can cause radiation sickness, long-term health effects, or contamination, correct signage is essential wherever these substances are handled.

Types of Class 7 Radioactive Signs

There are several different Class 7 signs, each with a specific purpose:

☢️ General “Radioactive” placard (White/Yellow)

  • Used when the shipment doesn’t require type categorisation or is used for general hazard warning.

☢️ Radioactive I (White/Yellow)

  • Used for packages with very low radiation levels.

  • Safe to handle with minimal shielding.

  • Features “RADIOACTIVE I” wording on a white background.

☢️ Radioactive II (White/Yellow)

  • Used for materials with moderate radiation levels.

  • Requires shielding and a Transport Index number to indicate safe handling distance.

  • Marked with “RADIOACTIVE II” wording on yellow and white background.

☢️ Radioactive III (White/Yellow)

  • Used for materials with higher levels of radiation.

  • Strictest handling requirements and mandatory documentation.

  • Features “RADIOACTIVE III” wording, yellow/white design, plus boxes for activity and transport index.

⚛️ Fissile Sign

  • Specifically for fissile radioactive materials (e.g. uranium-235, plutonium-239).

  • Alerts handlers that these materials can sustain a chain reaction if not properly controlled.

  • Required under UN regulations for fissile shipments — separate from general radioactive signage.

💡 Summary: Radioactive I, II, and III cover different intensities of radiation hazard, while the Fissile Sign identifies a unique criticality risk.

Class 7 Radioactive Signs are used to identify and label packages or vehicles transporting radioactive materials. These signs follow a consistent two-colour split design:

  • Upper section (yellow): Displays the black trefoil radiation symbol.

  • Lower section (white): Contains the text “Radioactive”, the hazard class number 7, and where required, details such as category (I, II, or III), transport index, and activity/contents information.

Compliance Requirements

  • Size: Minimum 250 mm per side for placards on transport vehicles. Larger sizes (400–800 mm) are recommended for depots, warehouses, and outdoor use.

  • Material: Signs must be durable and weather-resistant — laminated vinyl, PVC, Corflute, or ACM panels are standard.

  • Labelling vs Placarding: Small package labels may differ in size, but transport vehicles and containers require full-size placards.

Failure to display the correct signage can result in serious fines, shipment delays, and unnecessary risk to staff and emergency responders.

Why Class 7 Signs Matter

  • Legal compliance – Required under NZS 5433 and AS/NZS 1319:1994.

  • Worker safety – Warns staff and contractors of the need for radiation precautions.

  • Emergency response – Helps fire crews and HazMat teams act quickly with the right protective gear.

In short: the right sign isn’t just paperwork — it’s lifesaving communication.

Choosing the Right Sign

When deciding which Class 7 sign you need, consider:

  • Radiation intensity – choose I, II, or III depending on the hazard level.

  • Material type – fissile materials require the Fissile Sign, even if radiation levels are moderate.

  • Usage – transport vehicles, laboratories, hospitals, and depots all have different size and visibility requirements.

If you’re unsure, consult your dangerous goods documentation (UN numbers, packaging certificates) — these will specify the correct sign.

Where Class 7 Signs Are Used

  • Hospitals and clinics – transporting or storing radiopharmaceuticals

  • Laboratories – research samples and isotopes

  • Industrial sites – radiography, gauges, and test equipment

  • Transport vehicles – trucks, containers, and air freight carrying radioactive materials

  • Nuclear facilities – where fissile substances are moved or stored

FAQs – Class 7 Radioactive Signs

Q1: What’s the difference between Radioactive I, II, and III?
They represent increasing levels of radiation hazard. Class I is the lowest, Class III is the highest. Each requires different handling and safety measures.

Q2: When do I need a Fissile Sign?
Use the Fissile Sign when transporting fissile radioactive materials (like uranium-235 or plutonium-239) capable of sustaining a nuclear chain reaction.

Q3: What size does a Class 7 placard need to be?
Transport placards must be at least 250 mm per side. Larger options (400–800 mm) are recommended for high visibility in storage areas and depots.

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