UN Numbers for Radioactive Material: Complete Guide

Why UN Numbers Matter

The UN number is the starting point for everything on your shipping papers. It tells the carrier what they're hauling, tells emergency responders how to handle an accident, and tells the DOT inspector whether your paperwork matches your package. Get the UN number wrong, and your entire shipping paper is wrong.

I've seen shippers default to UN2915 (Type A) for every radioactive shipment because it's the one they use most often. The problem is that when you ship an excepted package as UN2915, you're adding unnecessary requirements—labeling, placarding, emergency response information—that don't apply. It wastes time, confuses carriers, and can actually create compliance issues because inspectors will expect to see documentation that matches a Type A shipment.

Choosing the correct UN number ensures your package moves through the system with the right level of regulatory oversight—no more, no less.

Who Needs to Know This

This applies to anyone who:

• Prepares shipping papers for radioactive material
• Marks or labels RAM packages
• Classifies radioactive material for transport
• Receives or accepts RAM shipments
• Audits hazmat shipping compliance

What Are UN Numbers?

UN numbers (also called UN IDs) are four-digit codes assigned by the United Nations Committee of Experts on the Transport of Dangerous Goods. Every hazardous material shipped anywhere in the world uses these standardized numbers. For radioactive material, the UN number tells you two things:

• What type of material or package you're dealing with
• What regulatory requirements apply to your shipment

In the US, these numbers appear in the Hazardous Materials Table (49 CFR 172.101), which is the master lookup table for all hazmat shipments. When you find your UN number in that table, the corresponding row tells you the proper shipping name, hazard class, packing group (if applicable), labels, and special provisions.

Excepted Packages: UN2908–UN2911

Excepted packages have the lowest regulatory burden. They don't require radioactive labels, placards, or the same level of shipping paper detail as other RAM shipments. There are four UN numbers covering different types of excepted packages.

UN2908 – Empty Packaging

Used for packages that previously contained radioactive material but have been emptied. The package must meet specific contamination limits: internal contamination must be less than the limits in 49 CFR 173.428, and external surface radiation must be below 0.5 mrem/hr.

The word “empty” is misleading here. The package may still have residual contamination—it just has to be below the regulatory thresholds. I've seen new shippers assume “empty” means the package was never used or is completely clean. That's not the case. UN2908 specifically applies to packages that were used and now have residual contamination within limits.

UN2909 – Articles Manufactured from Natural/Depleted Uranium or Natural Thorium

Covers manufactured articles (like counterweights, shielding, or ballast) made from natural uranium, depleted uranium, or natural thorium. These materials are radioactive but at low enough levels that they qualify as excepted when manufactured into solid articles.

UN2910 – Limited Quantity

For packages containing small amounts of radioactive material that fall below the A1/A2 activity limits specified in 49 CFR 173.425. The activity limits depend on the physical form of the material and the type of packaging.

UN2910 is probably the most commonly misapplied UN number. Shippers know their activity is low and assume they qualify, but they don't check whether the surface dose rate exceeds excepted package limits. Remember: both the activity and the dose rate must meet excepted package criteria.

UN2911 – Instruments or Articles

For instruments or manufactured articles containing radioactive material as a component, such as smoke detectors, gauge devices, or calibration sources installed in equipment. The radioactive material must be within activity limits specified in 49 CFR 173.424.

LSA and SCO: UN2912–UN2913

These UN numbers cover materials with low concentrations of radioactivity or objects with surface contamination.

UN2912 – Low Specific Activity (LSA)

LSA material has radioactivity that is essentially distributed throughout the material at low concentrations. There are three sub-categories (LSA-I, LSA-II, LSA-III) with different concentration limits defined in 49 CFR 173.403. Common examples include contaminated soil, low-level waste, and uranium ore.

LSA shipments are common in the waste and decommissioning world. If you're shipping contaminated debris from a site cleanup, you're probably looking at UN2912.

UN2913 – Surface Contaminated Objects (SCO)

SCO covers solid objects that aren't themselves radioactive but have radioactive contamination on their surfaces. There are two sub-categories (SCO-I and SCO-II) based on contamination levels. Think of contaminated tools, equipment, or building materials.

Type A and Type B: UN2915–UN2917

These are the UN numbers most RAM shippers encounter regularly. They cover packages with activity levels that require full DOT labeling, placarding, and shipping paper requirements.

UN2915 – Type A Package

The workhorse of radioactive shipping. Type A packages carry material with activity up to the A1 (special form) or A2 (normal form) limits. This covers the majority of routine RAM shipments—medical isotopes, calibration sources, industrial gauges, and more.

If you're shipping radioactive material that exceeds excepted package limits but stays within A1/A2 values, UN2915 is your number. It's the most common UN number I see in day-to-day RAM shipping.

UN2916 – Type B(U) Package

For material exceeding A1/A2 limits that requires a Type B package. The “(U)” stands for unilateral approval—the package design is approved by the country of origin only. Type B(U) packages must withstand severe accident conditions including a 9-meter drop test and fire exposure.

UN2917 – Type B(M) Package

Similar to UN2916, but the “(M)” stands for multilateral approval—meaning the package design must be approved by every country it passes through during transport. This is less common and typically applies to international shipments of high-activity sources.

Special Cases: UN2919, UN2977, UN2978

UN2919 – Special Arrangement

When a shipment doesn't fit neatly into the standard classification system, the shipper can apply for a special arrangement with the competent authority (DOT in the US). UN2919 covers these approved exceptions. This is uncommon—most shippers will never encounter it.

UN2977 – Uranium Hexafluoride, Fissile

Specifically for fissile uranium hexafluoride (UF₆), which has unique hazards because it's both radioactive and chemically reactive. Requires specialized packaging.

UN2978 – Uranium Hexafluoride, Non-Fissile

For non-fissile or fissile-excepted UF₆. Same chemical hazards as UN2977 but without the criticality concern.

Fissile Material: UN3321–UN3333

The UN numbers UN3321 through UN3333 include both additional non-fissile classifications not covered in the UN2908–UN2919 range (such as LSA-II, LSA-III, and Type A special form) and fissile counterparts for Type A, Type B, and special arrangement package types.

For example:

• UN3327 = Radioactive material, Type A package, fissile (the fissile version of UN2915)
• UN3328 = Radioactive material, Type B(U) package, fissile (the fissile version of UN2916)
• UN3332 = Radioactive material, Type A package, special form, non fissile or fissile-excepted

How to Determine Your UN Number

Selecting the correct UN number comes down to answering a series of questions about your material and package:

Step 1: Is the Material Fissile?

If yes, you're in the UN3321–UN3333 range. If no (or fissile-excepted), continue with the standard UN numbers.

Step 2: What Type of Package?

Your package type directly determines your UN number:

• Excepted package? → UN2908, UN2909, UN2910, or UN2911 (depends on contents)
• Industrial package (IP)? → UN2912 or UN2913 (LSA or SCO)
• Type A? → UN2915
• Type B(U)? → UN2916
• Type B(M)? → UN2917

Step 3: For Excepted Packages, What Are the Contents?

If you determined your package is excepted, narrow down further:

• Empty packaging? → UN2908
• Manufactured DU/thorium article? → UN2909
• Limited quantity of material? → UN2910
• Instrument or article containing RAM? → UN2911

The mistake I see most often is shippers skipping straight to UN2915 without considering whether their package qualifies as excepted. If your activity and dose rates are below excepted limits, using UN2910 or UN2911 saves you significant paperwork and labeling requirements. It's worth checking every time.

How RadShip.com Helps

RadShip.com simplifies UN number selection by:

• RAMcalc – Enter your nuclide, activity, and form. It determines whether your material qualifies as excepted, Type A, or Type B, and provides the correct UN number.
• LabelCalc – After classification, it generates the proper shipping name with UN number ready for your shipping papers.
• Built-in A1/A2 lookup for every nuclide so you don't have to manually search the table.

Classification is the step where most errors happen in RAM shipping. You're looking up A1/A2 values, comparing activity, checking dose rates, and cross-referencing package types—all before you even get to the shipping paper. A tool that handles the classification chain from nuclide to UN number eliminates the most error-prone part of the process.

Let RAMcalc handle the classification for you. Try it free for 7 days.

Common Questions

Can a package have more than one UN number?

No. Each package gets one UN number based on its contents and package type. If you're shipping multiple radioactive materials in one package, classify based on the combined contents and select the appropriate single UN number.

What's the difference between UN2915 and UN3327?

Fissile vs. non-fissile. UN2915 is a Type A package with non-fissile (or fissile-excepted) material. UN3327 is the same thing but with fissile material, which adds criticality safety requirements.

Do excepted packages still need shipping papers?

Yes, but simplified. Excepted packages (UN2908–UN2911) still require a shipping paper with the proper shipping name, UN number, and the statement “Radioactive material, excepted package.” However, they don't require the full emergency response information that labeled packages need.

Where does the UN number appear on the package?

On the package marking. For non-excepted packages, the UN number appears on the outside of the package along with the proper shipping name. For excepted packages, the marking requirement is “UN” followed by the number (e.g., “UN2910”) and “RADIOACTIVE” on the outer surface.

The bottom line is that UN numbers aren't just bureaucratic labels—they're the language that the entire hazmat transportation system uses to communicate. Getting the right UN number means your package flows through the system correctly, from pickup to delivery.

Summary: Your UN Number Selection Checklist

Before assigning a UN number, verify:

• ☐ You've determined whether the material is fissile or non-fissile
• ☐ You've classified the package type (excepted, IP, Type A, or Type B)
• ☐ For excepted packages, you've identified the correct sub-type (empty, article, limited quantity, instrument)
• ☐ You've verified the UN number matches the proper shipping name in the 49 CFR 172.101 table
• ☐ The UN number appears on both shipping papers and package markings
• ☐ You've applied the correct labeling requirements for your UN number

Or let RAMcalc determine the correct UN number automatically based on your material and activity.

Regulatory References

DOT Requirements:

• 49 CFR 172.101 – Hazardous Materials Table (UN number lookup)
• 49 CFR 173.403 – Definitions (LSA, SCO, fissile, etc.)
• 49 CFR 173.424 – Excepted packages for instruments and articles
• 49 CFR 173.425 – Excepted packages for limited quantities
• 49 CFR 173.428 – Excepted packages for empty packagings

IATA (Air Transport):

• IATA Dangerous Goods Regulations, Section 10 – Radioactive material requirements (uses same UN numbers)