Based on 49 CFR (DOT) and 10 CFR (NRC) as currently published in the eCFR
UN2912 and UN2913: LSA Material and Surface Contaminated Objects Explained
Everything you need to know about classifying and shipping low specific activity radioactive material and surface contaminated objects — including LSA subcategories, SCO contamination limits, Industrial Package types, and exclusive use provisions.
Quick Answer
UN2912 is the UN number for low specific activity (LSA) radioactive material — material where the activity is distributed throughout and the specific activity is inherently limited. UN2913 covers surface contaminated objects (SCO) — solid objects that are not themselves radioactive but have radioactive contamination on their surfaces. Both are non-fissile or fissile-excepted, defined in 49 CFR 173.403.
- UN2912 (LSA): Three subcategories — LSA-I, LSA-II, LSA-III — based on specific activity concentration
- UN2913 (SCO): Two subcategories — SCO-I, SCO-II — based on surface contamination levels
- Packaging: Requires Industrial Packages (IP-1, IP-2, or IP-3) — these are not excepted packages
- Requirements: Radioactive labels, Transport Index, and full shipping papers are required
Why LSA and SCO Matter
LSA material and SCO represent a huge volume of radioactive material shipments in the United States. Every time a nuclear facility decommissions equipment, processes radioactive waste, or moves contaminated soil, there is a good chance the material falls into one of these categories. The regulations provide a practical middle ground — the material is above excepted package thresholds, but the specific activity or contamination level is low enough that full Type A packaging is not always necessary.
I have seen it where shippers treat everything coming out of a radiological area as high-hazard material, defaulting to Type A packaging and handling for waste that clearly qualifies as LSA-I. On a large decommissioning project, that mistake multiplies fast — hundreds of extra drums, thousands of dollars in unnecessary packaging costs, and weeks of wasted time. Getting the LSA and SCO classification right is one of the highest-impact decisions you can make on a waste or decommissioning project.
Who Needs to Know This
UN2912 and UN2913 are most relevant to:
- Decommissioning projects: Contaminated soil, debris, concrete rubble, piping, and structural materials
- Radioactive waste operations: Evaporator bottoms, filter media, resins, solidified waste forms
- Nuclear facility maintenance: Contaminated tools, equipment, pipes, and components removed from controlled areas
- Uranium mining and milling: Ores, concentrates, and mill tailings
- Environmental remediation: Contaminated water, soil, and debris from legacy sites
- Research and medical facilities: Large-volume, low-activity waste streams
Important: UN2912 and UN2913 are specifically for non-fissile or fissile-excepted material. If your LSA material or SCO contains fissile material that is not excepted under 49 CFR 173.453, you must use UN2915 (LSA, fissile) or UN2917 (SCO, fissile) instead, which carry additional criticality safety requirements.
LSA Material Explained (UN2912)
Low specific activity material is radioactive material that, by its very nature, has a limited concentration of activity per unit mass. The activity is distributed throughout the material — not concentrated in a discrete special form source. The three LSA subcategories — defined in 49 CFR 173.403 — reflect increasing levels of specific activity and correspondingly stricter packaging requirements.
LSA-I: Lowest Activity Category
LSA-I covers materials with the lowest specific activity levels. These include:
- Uranium and thorium ores and their physical and chemical concentrates
- Unirradiated natural uranium or depleted uranium
- Unirradiated natural thorium
- Evenly distributed material with activity concentration ≤ 30 × the exempt concentration from Table 8
- Tritiated water with concentration ≤ 0.8 TBq/L
LSA-I is the most permissive category. It can be shipped in IP-1 packaging — the simplest Industrial Package type — and under exclusive use conditions, it can even be shipped unpackaged. That is a major distinction from every other category.
Practical tip: Most of the uranium ore and mill tailings shipments I have worked with fall squarely into LSA-I. The key qualification is that the material must be in its natural or unirradiated state. The moment you have irradiated uranium or processed material with higher concentrations, you are likely looking at LSA-II or LSA-III.
LSA-II: Moderate Activity Category
LSA-II covers material where activity is distributed throughout and the estimated average specific activity does not exceed certain limits based on the A2 value:
- Water with tritium concentration ≤ 20 TBq/L
- Solids and gases: Average specific activity ≤ 10⁻⁴ × A2/g
- Liquids: Average specific activity ≤ 10⁻⁵ × A2/g
Notice that liquids have a limit 10 times more restrictive than solids and gases. This reflects the greater dispersal risk that liquids pose in an accident scenario.
LSA-III: Solids Only
LSA-III is exclusively for solid material — no liquids or gases qualify. The activity must be distributed throughout a solid or a collection of solid objects, and the material must meet two conditions:
- Relatively insoluble: Leaching test result ≤ 0.1 × A2 released in one week
- Specific activity: Estimated average ≤ 2 × 10⁻³ × A2/g
The leaching test is the distinguishing feature of LSA-III. The material must be solid enough that even if the package fails and the material is exposed to water, no more than 0.1 A2 leaches out per week. This is why solidified waste forms — concrete or bitumen matrices with distributed activity — often qualify for LSA-III.
Tip: I worked with a waste processing facility that was solidifying evaporator bottoms into a cement matrix specifically to qualify the waste as LSA-III instead of LSA-II. The solidification step added cost, but the downstream savings on packaging — IP-2 instead of more robust containment for liquids — more than offset it. Sometimes the classification drives the waste form, not the other way around.
LSA Category Summary
| Category | Physical Forms | Key Limit | Common Examples |
|---|---|---|---|
| LSA-I | Solids, liquids, gases | ≤ 30 × exempt concentration; ores; unirradiated U/Th | Uranium ore, mill tailings, depleted uranium, tritiated water (≤ 0.8 TBq/L) |
| LSA-II | Solids, liquids, gases | Solids/gases: ≤ 10⁻⁴ × A2/g; Liquids: ≤ 10⁻⁵ × A2/g | Contaminated soil, evaporator bottoms, contaminated water |
| LSA-III | Solids only | ≤ 2 × 10⁻³ × A2/g; leaching ≤ 0.1 A2/week | Solidified waste forms, concrete with distributed activity, glass waste forms |
SCO Explained (UN2913)
Surface contaminated objects are fundamentally different from LSA material. With SCO, the solid object itself is not radioactive — the contamination exists only on its surfaces. Think of a wrench used in a hot zone, a pipe removed from a contaminated system, or a piece of equipment from a decommissioned reactor room. The object's bulk material is clean; the radioactivity is limited to what has deposited on accessible and inaccessible surfaces.
The regulations distinguish between two types of surface contamination:
- Fixed contamination: Contamination that cannot be removed from a surface during normal handling — it is physically bonded to the surface
- Non-fixed (removable) contamination: Contamination that can be transferred from the surface during normal handling — this is what a wipe test detects
They also distinguish between accessible and inaccessible surfaces. An accessible surface is one that can be contacted during normal handling. The inside of a sealed pipe, for example, would generally be inaccessible.
SCO-I Contamination Limits
| Surface & Type | Beta/Gamma & Low-Tox Alpha | All Other Alpha |
|---|---|---|
| Accessible — non-fixed | 4 Bq/cm² | 0.4 Bq/cm² |
| Accessible — fixed | 4 × 10⁴ Bq/cm² | 4 × 10³ Bq/cm² |
| Inaccessible — non-fixed | 4 × 10⁴ Bq/cm² | 4 × 10³ Bq/cm² |
SCO-II Contamination Limits
| Surface & Type | Beta/Gamma & Low-Tox Alpha | All Other Alpha |
|---|---|---|
| Accessible — non-fixed | 400 Bq/cm² | 40 Bq/cm² |
| Accessible — fixed | 8 × 10⁵ Bq/cm² | 8 × 10⁴ Bq/cm² |
| Inaccessible — non-fixed | 8 × 10⁵ Bq/cm² | 8 × 10⁴ Bq/cm² |
Common mistake: The most common mistake I see with SCO classification is people confusing total contamination with non-fixed contamination. You can have an object with very high fixed contamination and still qualify as SCO-I — as long as the non-fixed (removable) contamination on accessible surfaces stays under 4 Bq/cm². The wipe test measures non-fixed contamination. The direct survey measures total (fixed + non-fixed). You need both measurements to classify correctly.
Package Requirements: Industrial Packages
LSA material and SCO must be shipped in Industrial Packages — designated IP-1, IP-2, or IP-3. These are not excepted packages. They require radioactive labels, a Transport Index, and full shipping papers. The specific IP type depends on the LSA or SCO subcategory.
Industrial Package Types
- IP-1: Meets general packaging requirements of 49 CFR 173.410 — structurally sound, properly closed, no leakage under normal conditions
- IP-2: Meets IP-1 requirements plus withstands the free drop test (173.462) and stacking test (173.464)
- IP-3: Meets IP-2 requirements plus Type A packaging test requirements — essentially equivalent to a Type A package in performance
Required Package Type by Category
| Material Category | Non-Exclusive Use | Exclusive Use |
|---|---|---|
| LSA-I (all forms) | IP-1 | IP-1 or unpackaged |
| LSA-II (all forms) | IP-2 | IP-2 |
| LSA-III (solids only) | IP-2 | IP-2 |
| SCO-I | IP-1 | IP-1 or unpackaged |
| SCO-II | IP-2 | IP-2 |
Tip: My approach for selecting the package type is to start with the minimum required IP level and work up only if the physical characteristics of the material demand it. A standard steel drum meeting the free drop and stacking tests will satisfy IP-2. You do not need a custom-engineered container for most LSA-II or SCO-II shipments. However, for liquids in LSA-II, make sure your container meets the additional retention requirements — a leaking drum full of contaminated water is a bad day for everyone involved.
Exclusive Use Provisions
Exclusive use is a critical concept for LSA and SCO shipments. Under 49 CFR 173.403, exclusive use means the sole use of a conveyance by a single consignor, where all loading, unloading, and handling is directed by the consignor or consignee. This unlocks significant advantages:
- LSA-I and SCO-I may be shipped unpackaged — no Industrial Package required
- Higher dose rate limits at the vehicle surface — up to 2 mSv/h (200 mrem/h) instead of the standard package limits
- Unlimited activity per conveyance for all LSA and SCO categories
Dose Rate Limits for Unpackaged Material
When shipping LSA-I or SCO-I unpackaged under exclusive use, the following dose rate limits apply:
- ≤ 10 mSv/h (1,000 mrem/h) at 3 meters from the unshielded material
- ≤ 2 mSv/h (200 mrem/h) at the vehicle surface
- ≤ 0.1 mSv/h (10 mrem/h) at 2 meters from the vehicle surface
- ≤ 0.02 mSv/h (2 mrem/h) in any normally occupied space
Keep in mind: I have seen shippers lean on the exclusive use unpackaged provision as a cost-saving measure, but it comes with real operational requirements. You need a vehicle dedicated solely to your shipment, the driver cannot pick up other freight, and you as the shipper are responsible for directing loading and unloading. If the carrier mixes your LSA-I material with another customer's freight on the same truck, it is no longer exclusive use — and your unpackaged shipment just became non-compliant. Make sure the carrier understands and agrees to exclusive use conditions in writing before the truck leaves.
UN2912 vs UN2913: Key Differences
These two UN numbers address fundamentally different types of material. Understanding the distinction prevents misclassification:
| Feature | UN2912 (LSA) | UN2913 (SCO) |
|---|---|---|
| What is radioactive | The material itself — activity is distributed throughout | Only the surface contamination — the object itself is not radioactive |
| Physical forms | Solids, liquids, gases | Solid objects only |
| How limits are expressed | Specific activity (Bq/g or fractions of A2/g) | Surface contamination (Bq/cm²) |
| Subcategories | LSA-I, LSA-II, LSA-III | SCO-I, SCO-II |
| Classification basis | Activity concentration per gram | Surface contamination per cm² (fixed and non-fixed) |
| Common examples | Contaminated soil, radioactive waste, uranium ore, contaminated water | Contaminated tools, pipes, equipment, vehicles, reactor components |
| Fissile version | UN2915 | UN2917 |
Here's the reality: The line between LSA and SCO can get blurry in practice. A contaminated pipe, for example — if the contamination is only on the surfaces, it is SCO. But if the pipe material itself has become activated (neutron activation in a reactor environment, for instance), the pipe itself is now radioactive material, and you are looking at LSA, not SCO. The distinction matters because the classification criteria and limits are completely different. When in doubt, characterize the material thoroughly before classifying.
Common Practical Scenarios
Scenario 1: Decommissioning Waste Shipment
A nuclear facility is removing contaminated concrete and soil during decommissioning. The material has Cs-137 distributed throughout at an average specific activity of 3 × 10⁻⁵ × A2/g.
- A2 for Cs-137 = 0.6 TBq — the LSA-II limit for solids is 10⁻⁴ × A2/g
- Material is well within LSA-II limits (3 × 10⁻⁵ is less than 10⁻⁴)
- Ship as UN2912, LSA-II in IP-2 packaging
- Standard DOT-certified steel drums or B-25 boxes meeting drop and stacking tests
- Full shipping papers, radioactive labels, and TI required
Scenario 2: Contaminated Equipment from Hot Zone
Maintenance removed a valve and several hand tools from a contaminated work area. Wipe tests on accessible surfaces show non-fixed contamination of 2.5 Bq/cm² (beta/gamma). Direct surveys show fixed contamination at 1.8 × 10⁴ Bq/cm².
- Non-fixed on accessible surface: 2.5 Bq/cm² < 4 Bq/cm² (SCO-I limit) — passes
- Fixed on accessible surface: 1.8 × 10⁴ Bq/cm² < 4 × 10⁴ Bq/cm² (SCO-I limit) — passes
- Ship as UN2913, SCO-I in IP-1 packaging
- Under exclusive use, could ship unpackaged if dose rate conditions are met
Scenario 3: Uranium Mill Tailings
A remediation project is moving uranium mill tailings to a disposal cell. The tailings are natural uranium ore processing residue.
- Uranium mill tailings from natural ore processing qualify as LSA-I
- Under exclusive use, these can be shipped unpackaged (e.g., in dump trucks)
- Dose rate at 3m from unshielded material must be ≤ 10 mSv/h
- Vehicle surface dose rate must be ≤ 2 mSv/h
- Full shipping papers and placarding still required
Real case: I worked with a facility that was shipping contaminated soil from a remediation site. They initially classified everything as LSA-II and packaged it all in IP-2 drums. After a more detailed characterization, they found that a significant portion of the soil actually qualified as LSA-I based on the activity concentrations. By reclassifying that material, they were able to use IP-1 packaging for those shipments and saved roughly 30% on packaging costs across the project. The lesson: thorough characterization up front pays for itself.
How RadShip.com Helps
RadShip.com streamlines the LSA and SCO classification process:
- RAMcalc — Calculates specific activity against LSA-I, LSA-II, and LSA-III thresholds based on your isotope and A2 value, and determines the correct UN number and Industrial Package type
- Generates compliant shipping papers with the correct proper shipping name, UN number, and all required Class 7 entries
- Identifies whether your shipment qualifies for exclusive use provisions and the associated reduced packaging requirements
Here's the reality: LSA and SCO classification involves looking up exempt concentrations, calculating specific activity against A2-based limits, or comparing surface contamination against multiple limit categories simultaneously. These are not difficult calculations individually, but when you are processing dozens of waste streams on a decommissioning project, it is easy to make an error that either over-classifies (costing money) or under-classifies (creating a violation). Having a tool that handles the lookups and comparisons automatically keeps your shipments compliant and your costs in check.
Common Questions
Can LSA or SCO material be shipped as an excepted package?
No. LSA and SCO are distinct from excepted packages. They require Industrial Packages with full radioactive labels, a Transport Index, and complete shipping papers. The “low” in low specific activity refers to the concentration of activity — not the regulatory burden. This is one of the biggest misconceptions I encounter.
What is the difference between LSA-II and LSA-III?
LSA-III is for solids only and requires a leaching test. LSA-II allows all physical forms (solids, liquids, gases) with specific activity limits based on the A2 value. LSA-III has a higher specific activity limit (2 × 10⁻³ × A2/g vs. 10⁻⁴ × A2/g for solids) but requires the material to be relatively insoluble — releasing no more than 0.1 A2 when subjected to a week-long leaching test. This makes LSA-III ideal for solidified waste forms.
Can I ship SCO without any packaging?
Only SCO-I under exclusive use conditions. The object must meet the SCO-I contamination limits, the conveyance must be under exclusive use, and the applicable dose rate limits must be met. SCO-II always requires IP-2 packaging regardless of whether you use exclusive use.
How do I handle a mixture of LSA and SCO in the same shipment?
Each item must be classified individually. You may ship both LSA material and SCO in the same conveyance, but each package must meet the requirements for its respective classification. The packaging type is determined by the highest category present — if you have both LSA-I and LSA-II material, the entire shipment must meet the LSA-II packaging requirements (IP-2) unless the materials are in separate, individually compliant packages.
Summary: Your LSA/SCO Shipping Checklist
Before shipping UN2912 (LSA) or UN2913 (SCO):
- ☐ Material characterized — specific activity or surface contamination measured
- ☐ Correct subcategory determined (LSA-I/II/III or SCO-I/II)
- ☐ Fissile status confirmed — non-fissile or fissile-excepted (otherwise use UN2915 or UN2917)
- ☐ Correct Industrial Package type selected (IP-1, IP-2, or IP-3)
- ☐ Package meets applicable test requirements (general design, drop test, stacking test)
- ☐ Radioactive labels applied (WHITE-I, YELLOW-II, or YELLOW-III)
- ☐ Transport Index calculated and marked on labels
- ☐ UN number marked on package — “UN2912” or “UN2913”
- ☐ Shipping papers prepared with proper shipping name, UN number, activity, physical/chemical form
- ☐ External contamination within limits per 49 CFR 173.443
- ☐ Exclusive use conditions documented and agreed upon with carrier (if applicable)
- ☐ Dose rate surveys performed and within applicable limits
Regulatory References
DOT Requirements:
- 49 CFR 173.403 — Definitions (LSA-I, LSA-II, LSA-III, SCO-I, SCO-II, exclusive use)
- 49 CFR 173.427 — Transport requirements for LSA material and SCO (Table 6)
- 49 CFR 173.410 — General design requirements (IP-1 basis)
- 49 CFR 173.462 — Free drop test for IP-2 and IP-3
- 49 CFR 173.464 — Stacking test for IP-2 and IP-3
- 49 CFR 173.443 — Contamination control (Table 9)
- 49 CFR 173.435 — Table of A1 and A2 values
- 49 CFR 173.453 — Fissile material exemptions
About the Author
Scott Brown is the Subject Matter Expert and co-creator of RadShip.com. He has been a trained hazmat shipper for over 15 years and specializes in DOT Class 7 radioactive material shipping.
This guide is based on the requirements of 49 CFR (DOT), 10 CFR (NRC), and the IATA Dangerous Goods Regulations as of the publication date. As regulations are amended, RadShip.com is committed to keeping its guides current with the latest requirements.
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