We covered the basics of MIL-STD-2073 in an earlier post — what it covers, the three components (preservation, packaging, packing), and the A/B/C levels of protection. One question that comes up constantly once contractors get that far: if Level C in MIL-STD-2073 just points to ASTM D3951, why do both standards exist, and how do you know which one your contract actually needs?
Here’s the practical difference.
Two Standards, Two Purposes
MIL-STD-2073-1 is a Department of Defense standard. It’s written for materiel that has to survive the defense supply chain specifically — extended and sometimes indefinite storage, multiple handling points, worldwide shipment, and exposure to whatever climate and terrain a given deployment throws at it. It assumes the item may sit in a container or warehouse for a long time before anyone opens it, and it has to come out ready to use.
ASTM D3951 is a civilian standard published by ASTM International — the “Standard Practice for Commercial Packaging.” It’s built around commercial shipping conditions: a package that moves through a distribution network in a matter of days or weeks, not years, and doesn’t need to withstand the same extremes of climate and handling that a Level A or B military pack does.
Neither standard is “better” than the other — they’re built for different journeys. The mismatch happens when a contractor applies the wrong one to the wrong item.
Where They Meet: Level C
MIL-STD-2073 doesn’t ignore commercial packaging — it incorporates it. When an item’s Packaging Requirement Code (PRC) calls for Level C (Commercial), the contract is telling you the item doesn’t need Level A or B protection, and ASTM D3951 packaging is acceptable. This is common for items that are rugged by nature, low-value, or headed somewhere with a short, predictable shipping and handling path.
So in practice, most contractors aren’t choosing between MIL-STD-2073 and ASTM D3951 in the abstract — they’re reading the PRC on their specific contract, which tells them exactly which level (A, B, or C) applies to that item, and therefore which packaging approach to use.
Marking Applies Either Way
One detail that gets missed: choosing Level C doesn’t mean the marking requirements go away. Shipments to DoD still need to be marked in accordance with MIL-STD-129, regardless of whether the pack itself was built to full MIL-STD-2073 levels or to ASTM D3951 commercial packaging. Contractors sometimes treat “Level C” as “commercial packaging, commercial rules” across the board — and then get flagged for marking, not for the pack itself.
Why the Distinction Matters
Getting this wrong runs in both directions, and both are costly:
- Over-packaging — building a Level A pack for an item the PRC specifies as Level C wastes material, labor, and money on protection the contract doesn’t require or pay for.
- Under-packaging — using commercial-grade ASTM D3951 packaging for an item the PRC specifies as Level A or B risks damage in transit, failed DCMA inspection, and a rejected shipment that has to be repacked and resubmitted — on your schedule, not the government’s.
The fix in both cases is the same: read the packaging requirement code for the specific item before building the pack, not after.
The Short Version
MIL-STD-2073 is the military packaging standard for items that need to survive the defense supply chain. ASTM D3951 is the commercial packaging standard, and MIL-STD-2073 explicitly permits it for Level C items. The PRC on your contract tells you which one applies — and no matter which one you use, MIL-STD-129 marking requirements still apply to shipments going to DoD.