The Real Boundaries of UN Performance Level Marking for Export Dangerous Goods Packaging: The 3 Fields Printers Most Often Misread—Packaging Type Code / Relative Density / Pressure Test Value

On the evening of October 8, 2026, the business manager of a printing plant in Suzhou that produces color boxes and inner trays received an English message from a Vietnamese customer via WeChat. The attachment was a sample image showing a UN performance grade label, and the customer said: “Just print it exactly as shown, red ink, we only need the box.” (Just print it as shown, using red ink; we only need the box.)

The diagram is labeled 1A2/Y1.4/150/25/USA/+AB123. The sales manager forwarded the design file to the prepress team, who completed the layout and produced the printing plates. Seven days later, the batch of inner trays shipped to Vietnam, but the customer’s third-party testing laboratory returned the samples for one reason only: “The performance-grade designation in Section 4 does not match the measured packaging data.”

Broken down, this string of markings contains 3 printing errors. Each of these 3 is a pitfall that print shops most commonly fall into when “following the design draft” to print.

What Do UN Performance Grades Mean: 7 Mechanical Codes, Not Product Model Numbers

The red diamond mark on export dangerous goods packaging (lithium battery inner trays, chemical drums, and dangerous goods transport boxes) does not indicate a product model, customer part number, or a name invented by the packaging manufacturer. It is the package specification mark specified in the United Nations Recommendations on the Transport of Dangerous Goods—Model Regulations. It consists of 7 segments, each of which contains measured or registered data, and not a single character may be descriptive in nature.

段位What to writeTested/Registered SourceCan the printing plant make its own decision?1Package type code, e.g., 1A2 / 4G / 4CRegistration of package design type and materialNo2Solid contents (S) or liquid contents (L)Packaging test conditionsNot applicable3Hazard class letters, X/Y/ZPackaging strength level testNo4Relative density (for liquids) or hydrostatic pressure value kPa (for solids)MeasuredCannot5Year of manufacture (2 digits)Date of manufactureNot available6Country of Origin CodePlace of ProductionCannot7Manufacturer codePackaging plant registration numberCannot

In other words, not one of these 7 segments can be assigned by the printer “based on experience.” The entire series was copied verbatim from the packaging manufacturer’s test report; the printer merely transferred it from the report to the carton. The Vietnamese shipment was returned not because the printing was misaligned, but because the figures in segment 4 did not match the box’s actual test data—and the printer had never requested that report from the customer before printing.

Boundary 1: The three pieces of information in packaging type code 1A2 are copied together as a single "model designation"

1A2 Each of these three digits has an independent meaning: the first digit 1 indicates a bucket/box-type package for solid contents (4 indicates a fiberboard box, and 3 indicates a case), the second digit A indicates steel material (B aluminum, C natural wood, D plywood, F fiberboard, G fiberboard, with G types further subdivided by an additional digit), and the third digit 2 indicates a non-removable inner lining (1 indicates a removable one).

The most common mistake printing companies make is to treat 1A2 as the customer’s complete product model. When the customer places an order and says, “We want 1A2 drums,” the printing company checks its own price list to see whether there is a 1A2 option. If there is none, it asks the customer, “Do you mean the 1A2 model we quoted last time?” The “1A2” in these two statements refers to two completely different things: one is a UN specification code, while the other is the printing company’s internal product numbering convention.

What the printing factory can actually do: During pre-review, split the seven segments of this string of identifiers into a table and return it to the customer, requiring the customer to confirm each segment in writing and explicitly stating: “The factory will print only the content confirmed by the customer and is not responsible for the accuracy of the identifier content.” This is not shirking responsibility; it clearly defines the printing factory’s actual role in the chain—the factory does not conduct packaging tests or manufacture packaging structural components, and only handles the printed surface.

Boundary 2: A relative density of 1.4 is treated as "product density" or "filling density"

Paragraph 4 states relative density for liquid packaging (1.4 means that the packaging has undergone a liquid filling test using a liquid with a density of 1.4), and the hydrostatic test pressure value for solid packaging (150 means 150 kPa). Neither value refers to the density of the customer's product, nor to what the printing factory understands as "the weight contained in this carton."

Here is how this actually happened: The customer verbally stated, “We are filling it with a liquid with a density of 1.4,” so the printing plant simply entered 1.4 in segment 4 of the mark. In reality, the customer’s liquid had a density of 1.25; 1.4 was the more stringent condition selected by the packaging plant for testing that year. The printing plant followed the customer’s verbal instructions, but the customer’s transportation carrier specified packaging according to the 1.4 grade. The actual test failed. The printing plant was responsible because it was the party that printed the number on the mark.

Another, subtler mistake is writing 1.4 as 1,4 or 1.40. The United Nations format templates specify the format for this section: use a solid decimal point, do not use thousands separators, and do not add trailing zeros. Such formatting errors may be completely undetectable when proofreading by eye, but they will be automatically deemed noncompliant during the inspection authority’s format validation.

What the printing plant can actually accept: During the pre-review stage, only two sources are recognized—a test report PDF issued by the packaging plant, or a specification sheet signed and confirmed by the customer. If the customer says in a WeChat group that the figure is “around 1.4,” always revert to written confirmation by email, and the email must repeat the figure for the customer to reply “Confirmed.”

Boundary 3: The production year 25 is printed as 2025

Paragraph 5 contains a two-digit year, not a four-digit one. Packaging produced in 2025 should be marked 25, and packaging produced in 2026 should be marked 26. This is the element that is most often “helpfully” altered: layout colleagues at the printing plant see “2025” on the design, think that two digits look too short and unprofessional, and take it upon themselves to change it to 2025.

This is not a matter of formatting pedantry. The purpose of the year code is to determine whether the packaging has exceeded its periodic inspection interval—dangerous goods packaging generally requires periodic design type testing or requalification in most countries/regions, and the year code serves as the reference point for inspection authorities to trace its history. An incorrect year amounts to fabricating an inspection date for the entire batch of packaging; if a subsequent transport accident occurs, the traceability chain is broken at the marking stage.

There is also a related issue: the country-of-origin code in paragraph 6. USA stands for the United States, CHN for China, and DEU for Germany. The printing plant is in Wuxi, so CHN is factually correct for the country of origin. However, if the customer is using branded packaging from a packaging plant, with the packaging produced in Vietnam and the printing plant providing only printing services, what should be stated in this paragraph depends on which company the term “packaging plant” refers to within the supply chain. This must be clarified during the pre-review stage, rather than assumed by the printing plant on the customer’s behalf.

3 Types of Response Actions for Printing Plants

Action 1: Break the mark down into a 7-section confirmation table. Upon receipt of an order containing a UN performance level mark, do not modify the artwork before printing; first prepare a table with one row per section, and have the customer reply “Confirmed” or provide the correct value for each row. Archive this table together with the customer’s reply.

Action 2: Request the source file. Tell the client: “Every number in this string of identification marks must be supported by the packaging factory’s test report, and we will print according to the report. Would it be convenient to provide a scanned copy of the report?”—This sentence keeps the most dangerous data source, namely “the client’s verbal description,” outside the process.

Action 3: Add a statement to the dispatch note. On the dispatch note/delivery note, specify: “The UN specification markings shall be confirmed in writing by the customer. The factory shall print solely according to the confirmed content, and the confirming party shall be responsible for the accuracy of the markings.” In the event of an accident investigation, the value of this statement is generally equivalent to the value of an entire shipment.

Further Reading

Four Compliance Requirements for Packaging Exported to the EU: REACH / 1935/2004 / 94/62/EC / EN 13427

Three Compliance Hurdles for Packaging Exports to the United States: What FDA, Prop 65, and CPSIA Each Regulate

Real-World Data on 6 Packaging Inspection Methods

Packaging Box Supplier Factory Audit: 6 Types of Real Actions

3 Types of Copyright Risks When Customers Provide Their Own Designs