Marking Requirements for Radioactive Material Packages (Ground)

Why Package Markings Matter

Markings are the cheapest part of a Class 7 shipment to get right and one of the most common reasons a shipment gets stopped. A marking problem costs pennies to fix at your dock and a full transit cycle to fix after a carrier refuses the package — and carriers do refuse. The acceptance clerk cannot see your classification math, but they can absolutely see a missing UN number or an absent “TYPE A” marking.

In fifteen years of shipping Class 7, the rejections I have seen were rarely about the hard parts of the job. They were about a shipping name that never made it onto the box, an ID number printed too small, or an old marking from the package's previous life that nobody covered up. The classification was fine; the felt-tip work was not.

Marking is Step 5 territory in the overall Class 7 shipping process — where your classification becomes visible on the box, and where an inspector checks that the package, the labels, and the shipping paper all tell the same story.

Who Needs to Know This

This applies to anyone who:

• Physically prepares Class 7 packages for ground shipment — the person with the marker, the stencil, or the label printer
• Signs shipping papers and needs to verify the package matches the document before it leaves
• Receives radioactive packages and wants to know what a compliant package should look like on arrival
• Audits or inspects hazmat operations and needs the marking checklist in one place

Marking vs. Labeling: Two Different Requirements

The regulations treat these as separate obligations, and so do inspectors. Marking is the written information applied to the package — words, numbers, and addresses required by 49 CFR Part 172, Subpart D. Labeling is the diamond-shaped hazard communication — the RADIOACTIVE WHITE-I, YELLOW-II, and YELLOW-III labels required by Subpart E. A fully marked package with no labels is a violation; a fully labeled package with no markings is a different violation.

This guide covers the marking side. For label selection, the entries on the label, and the Transport Index, see the labeling basics guide.

What Every Non-Bulk Package Must Be Marked With (172.301)

49 CFR 172.301 sets the baseline for every non-bulk hazmat package, radioactive or not.

Proper Shipping Name and UN Number

Under 172.301(a)(1), the package must be marked with the PSN and identification number from the 172.101 Hazardous Materials Table, with the identification number preceded by “UN,” “NA,” or “ID” as appropriate. Every Class 7 entry carries a UN prefix, so for radioactive material this means markings like “UN2915, Radioactive material, Type A package” — the UN numbers guide covers how your classification lands on one of the twenty Class 7 entries.

The identification number marking has minimum character heights, and this is where packages fail tape-measure checks:

My advice: ignore the small-package allowances and print the UN number at 12 mm or larger on everything. I have watched an inspector put a ruler against a package, and I have never once regretted a marking being too big. The allowances exist for packages that physically cannot fit larger characters — not to save toner.

Consignor or Consignee Name and Address

Under 172.301(d), each non-bulk hazmat package must be marked with the name and address of the consignor or the consignee — either one satisfies the rule. There are two exceptions: packages transported by highway only that will not be transferred from one motor carrier to another, and packages that are part of a carload, truckload, or freight container load where the entire contents ship from one consignor to one consignee.

In practice, I mark the address on every package and skip the exception analysis entirely. The exception depends on how the carrier routes the package — something you do not control after tender — and an address block costs nothing.

Special Permit Packages

If your package is authorized by a special permit, 172.301(c) requires the outside to be plainly and durably marked “DOT-SP” followed by the special permit number. Packages under an exemption issued before October 1, 2007 may carry the older “DOT-E” form instead.

The Class 7-Specific Markings (49 CFR 172.310)

49 CFR 172.310 adds requirements that apply only to radioactive material packages, on top of everything above.

Gross Weight Marking Over 50 kg

Under 172.310(a), each package with a gross mass greater than 50 kg (110 lb) must have its gross mass, including the unit of measurement, marked on the outside of the package. The unit may be abbreviated — “62 kg” works.

Weigh the finished, closed package — do not add up tare and contents from a spec sheet. Shielded packages gain weight in ways spec sheets forget: extra dunnage, a different liner, the pallet nobody mentioned. A marked weight that disagrees with the carrier's scale invites exactly the second look you do not want.

The Package Type Marking: TYPE A, TYPE B(U), TYPE IP-#

Under 172.310(b), each industrial, Type A, Type B(U), or Type B(M) package must be legibly and durably marked on the outside, in letters at least 12 mm (0.47 in) high, with “TYPE IP-1,” “TYPE IP-2,” “TYPE IP-3,” “TYPE A,” “TYPE B(U),” or “TYPE B(M),” as appropriate. Which of these your shipment needs is determined back at classification — see package types explained.

The same paragraph contains the rule people miss: a package that does not conform to the Type IP-1, IP-2, IP-3, Type A, B(U), or B(M) requirements may not be so marked. The marking is a conformity claim, not a description of intent.

The most common version of this mistake I see is the reused vendor box. A lab receives sources in a genuine Type A package, keeps the box, and later ships something else in it with the original “TYPE A” marking still on the side. If the package as prepared no longer meets the Type A design — different contents, missing inner components, no documentation tying it to the tested design — that marking is a false conformity claim. Re-establish conformity, or take the marking off.

Country of Origin of the Design: the USA Marking

Under 172.310(c), each package conforming to an IP-1, IP-2, IP-3, or Type A design must be marked with the international vehicle registration code of the country where the package was designed — “USA” for packages designed by a United States company or agency. On a domestic Type A box this typically appears right alongside the “TYPE A” marking.

Type B Packages: the Embossed Trefoil and the Certificate Marking

Type B packages carry two additional marking obligations:

• Embossed radiation symbol (172.310(d)): the outside of the outermost fire- and water-resistant receptacle must be plainly marked — by embossing, stamping, or other means resistant to fire and water — with a radiation symbol conforming to appendix B of Part 172. The point is that even if a fire consumes every printed label, the trefoil survives on the metal.
• Package identification marking (173.471(b)): for NRC-approved packages, the outside must be durably and legibly marked with the package identification marking from the NRC packaging approval — and under 173.471(c), the same marking must appear on the shipping paper.
• Export shipments (172.310(e)): each Type B(U), Type B(M), or fissile material package destined for export must also be marked “USA” in conjunction with the specification marking or other package certificate identification.

Putting It Together: a Marked Type A Package

How Markings Must Be Applied (49 CFR 172.304)

49 CFR 172.304 governs the quality of every marking in the subpart. Each required marking must be:

• Durable, in English, and printed on or affixed to the surface of the package or on a label, tag, or sign
• Displayed on a background of sharply contrasting color
• Unobscured by labels or attachments — your RADIOACTIVE label cannot sit on top of the UN number
• Located away from any other marking (such as advertising) that could substantially reduce its effectiveness

The failure mode I see most is not the initial application — it is what happens between your dock and the destination. Inkjet-printed markings smear in the first rain; packing tape run across a marking can lift it clean off at the next handling point. Print with something waterproof, keep the closure tape off the markings, and give the finished package the ten-second look: can I read every marking at arm's length, and will I still be able to after a wet ride in three trucks?

Prohibited Markings (49 CFR 172.303)

49 CFR 172.303 is the mirror image of everything above: no person may offer or transport a package marked with a proper shipping name, an identification number, or any other marking indicating the material is hazardous (the rule gives “RQ” and “INHALATION HAZARD” as examples) unless the package actually contains that hazardous material or its residue.

For Class 7 shippers this rule bites in one specific place: package reuse. That sturdy box marked “UN2915” from last month's inbound shipment cannot carry your non-hazardous return shipment with the markings intact. The section does allow markings that are securely covered in transportation — but my standing practice is simpler: before any package leaves my dock, every marking on it is either true or gone. Obliterate old markings with paint or opaque tape rather than litigating the exceptions, because “securely covered” gets judged after the tape peels, not before.

What About Orientation Arrows for Liquids?

Mostly, you are off the hook. 49 CFR 172.312 requires orientation arrow markings on two opposite vertical sides of most non-bulk packages with inner packagings of liquid hazardous materials — but paragraph (c)(7) exempts Class 7 radioactive material in Type A, IP-2, IP-3, Type B(U), or Type B(M) packages.

Note what the exemption does not cover: it lists specific package types, and a liquid radioactive shipment in a package outside that list does not inherit the relief. If you ship liquid Class 7 in anything other than the exempted types, check 172.312(a) before assuming arrows are optional — and under 172.312(b), arrows for any purpose other than orientation may not appear on a liquid hazmat package at all.

How RadShip.com Helps

RadShip.com connects marking to the classification it depends on:

• RAMcalc classifies your material to the UN number, proper shipping name, and package type — the exact text your markings must carry — so the box and the math always agree.
• LabelCalc handles the other half of the package face: label category and Transport Index, so marking and labeling are built from the same inputs.
• The generated shipping paper uses the same PSN and UN number, which closes the classic gap where the box says one thing and the paperwork says another.

Marking errors are almost never math errors — they are transcription errors. When the UN number on the package, the label, and the shipping paper all flow from a single classification instead of being retyped three times, the transcription step disappears, and with it most of the ways a marking check can go wrong.

Try it free for 7 days.

Common Questions

What is the difference between marking and labeling a package?

Marking is written information; labeling is the hazard diamond. Markings — PSN, UN number, TYPE A, gross weight, addresses — come from Part 172 Subpart D. Labels — RADIOACTIVE WHITE-I, YELLOW-II, YELLOW-III — come from Subpart E and are covered in our labeling guide. Inspectors cite them separately, so a package must satisfy both.

How big does the UN number marking have to be?

At least 12 mm (0.47 in) for standard packages. 172.301(a)(1) allows 6 mm (0.24 in) characters for packages of 30 L or 30 kg net mass or less (and cylinders of 60 L water capacity or less), and a “size appropriate” marking at 5 L or 5 kg and below. When in doubt, go bigger.

When do I have to mark the gross weight on a radioactive package?

When gross mass exceeds 50 kg (110 lb). Under 172.310(a), the gross mass including the unit of measurement must be marked on the outside. Weigh the finished package rather than calculating it — the marked number should survive a meeting with the carrier's scale.

Can I reuse a box that has old hazmat markings on it?

Not with the old markings showing. 172.303 prohibits offering a package marked for a hazardous material it does not contain (residue excepted). Remove or obliterate old markings — and remember the companion rule in 172.310(b): a “TYPE A” marking may only stay on a package that actually conforms to a Type A design.

Do radioactive packages need orientation arrows?

Usually not. 172.312(c)(7) exempts Class 7 material in Type A, IP-2, IP-3, Type B(U), and Type B(M) packages. Liquid radioactive material in a package type not on that list should be checked against 172.312(a).

What does the “USA” marking on a radioactive package mean?

It identifies the country where the package was designed. 172.310(c) requires IP-1, IP-2, IP-3, and Type A packages to carry the international vehicle registration code of the design country — “USA” for U.S.-designed packages. For Type B and fissile packages going to export, 172.310(e) requires “USA” in conjunction with the package certificate identification.

My overall take: marking has the best effort-to-risk ratio in Class 7 compliance. No calculation, no judgment calls — just a checklist, decent materials, and thirty seconds of looking at the finished package. Spend the thirty seconds. It is the cheapest inspection insurance you will ever buy.

Summary: Your Package Marking Checklist

Before a Class 7 package leaves your dock, confirm:

• ☐ Proper shipping name and UN number marked, matching the 172.101 entry and the shipping paper exactly
• ☐ Identification number characters at least 12 mm (0.47 in) high — or the applicable small-package allowance verified
• ☐ Consignor or consignee name and address marked (or a documented exception applies)
• ☐ Gross mass with unit marked if the package exceeds 50 kg (110 lb)
• ☐ “TYPE IP-#,” “TYPE A,” “TYPE B(U),” or “TYPE B(M)” marked in letters at least 12 mm high — and the package genuinely conforms to that design
• ☐ Country-of-design code (“USA”) marked on IP and Type A packages
• ☐ Type B only: embossed/stamped radiation symbol present; NRC package identification marking on the package and the shipping paper; “USA” certificate marking for export
• ☐ DOT-SP number marked if shipping under a special permit
• ☐ All markings durable, in English, on contrasting background, not covered by labels or tape
• ☐ No leftover markings from previous contents — everything on the box is true or gone

Regulatory References

DOT Requirements:

• 49 CFR 172.301 – General marking requirements for non-bulk packagings (PSN, ID number, sizes, consignor/consignee)
• 49 CFR 172.303 – Prohibited marking
• 49 CFR 172.304 – Marking requirements (durability, language, contrast, visibility)
• 49 CFR 172.310 – Class 7 (radioactive) materials special marking requirements
• 49 CFR 172.312 – Liquid hazardous materials in non-bulk packagings (orientation arrows and the Class 7 exemption)
• 49 CFR 173.471 – Requirements for NRC-approved packages (package identification marking)

NRC Requirements:

• 10 CFR Part 71 – Packaging and transportation of radioactive material (source of the packaging approvals whose identification markings 173.471 requires)

IATA (Air Transport):

• IATA Dangerous Goods Regulations, Section 7 (Marking & Labelling) and Section 10 (Radioactive Material) – additional and modified marking requirements for air shipments