The PPWR heavy metal limit is a combined ceiling: lead, cadmium, mercury and hexavalent chromium must total no more than 100 milligrams per kilogram of the packaging or packaging component being assessed. For a printed rigid box with a removable insert, the useful question is which part a result describes. A low result for the box base establishes something different from a low result for the insert—and a result for unprinted board leaves the added printing and finishes unaddressed.
Regulation (EU) 2025/40 has generally applied since August 12, 2026. Its heavy-metal ceiling carries forward the numerical limit under the earlier Packaging and Packaging Waste Directive 94/62/EC. As the European Commission explains, EU packaging rules cover packaging regardless of material or origin. A paper gift box made in China for products placed on the EU market is within that scope; food contact is not a condition for the heavy-metal restriction to apply.
Four substances share one limit
The calculation under Article 5(4) is:
Lead (Pb) + cadmium (Cd) + mercury (Hg) + hexavalent chromium (Cr(VI)) ≤ 100 mg/kg.
All four concentrations must refer to the same assessed packaging or component and use a consistent mass basis. The limit is equivalent to 100 parts per million by mass, or 0.01%.
The 100 mg/kg allowance is shared by all four substances. For example, 80 mg/kg of lead and 30 mg/kg of cadmium already produce a combined concentration of 110 mg/kg, before mercury or hexavalent chromium is included. Conversely, measurable lead does not automatically mean a failure: the relevant comparison is the four-substance sum against the combined ceiling.
The kilogram belongs to the packaging or component assessed
Milligrams per kilogram expresses concentration. It does not require a package to weigh one kilogram, and it does not provide an allowance of 100 milligrams for every box. The denominator is the mass of the relevant packaging or component, excluding the product inside. Adding a heavier product cannot change the packaging’s concentration.
Consider the printed base and removable insert of a lid-and-base gift box. The lid is a further component; this illustration compares just the base and insert. Assume separate assessments produce the following results:
| Component | Component mass | Combined four-metal concentration | Corresponding mass of the four metals |
|---|---|---|---|
| Printed box base | 300 g | 20 mg/kg | 6 mg |
| Removable insert | 50 g | 160 mg/kg | 8 mg |
The base is below the ceiling; the insert exceeds it. If the two were blended into one calculation, their combined 14 mg of metals divided by 0.35 kg of packaging would give just 40 mg/kg. That low average conceals the insert’s higher concentration. Although the insert contains only 8 mg of the metals in absolute terms, 8 mg within a 50 g component equals 160 mg/kg.
A passing average across an assembled pack does not, by itself, establish that its separate components meet the limit. The removable insert needs evidence that addresses it. This is why a report’s sample description and any mixing of parts during sample preparation matter as much as the headline result.
What counts as a component in a printed rigid box?
A rigid box may combine greyboard, printed wrapping paper, adhesive and a surface finish. Its insert may introduce another paper, foam, fabric or plastic. To understand the concentration limit, we need to distinguish the components of that pack from the materials making up each component.
For describing the construction, the terminology reproduced in CEN/TR 13695-2:2019 provides a useful distinction. A packaging component is a part that can be separated by hand or simple physical means. A packaging constituent is a part from which packaging or its components are made that cannot be separated that way.
In the gift box above, the lift-off lid, base and removable insert are distinct components. Now consider the construction within the base. Suppose its wrap is bonded to the board so that they cannot be separated by hand or simple physical means. The board, wrap, dried printing ink, adhesive and inseparable coating are then constituents of that bonded component. Its assessment needs to account for their contributions within the finished base. Combining those constituent contributions describes one component; averaging the base with the removable insert merges two distinct components.
Being attached or glued does not automatically make a part inseparable. A wrap or decorative piece that can be separated by hand or simple physical means needs to be reflected in the component breakdown. A removable decorative band is a component; a transferred foil layer that cannot be separated from its substrate that way is a constituent. The construction determines the distinction, rather than whether a detail is decorative, thin or light.
What a finished-component result should cover
Evidence intended to cover the finished printed base must account for its board, wrap, applied ink, adhesive and finish. A suitable assessment may use representative testing of the finished component, traceable information about its constituents, or both. A test of unprinted board alone leaves the added materials unaddressed. A report intended to cover the complete gift box must also support conclusions about its lid, insert and any other relevant components.
When constituent data are used to calculate a component’s concentration, their contributions must be weighted by the amounts present in the finished component. A raw ink result has ink as its mass basis; it cannot simply be substituted for the concentration in the printed base. Wet ink or adhesive quantities also differ from the amounts remaining after drying. The calculation therefore needs suitable constituent data and the finished construction’s material proportions.
The laboratory’s prepared sample is a third, separate concept. Cutting, grinding or extracting material makes it suitable for analysis; those steps do not themselves redefine the packaging component. A blank offcut alone leaves printed or decorated areas unrepresented. Pooling equal quantities of different materials may create proportions unlike the finished component. And grinding a base and insert together still produces a mixed result that needs interpretation before it can support conclusions about either component.
At CMIC, we can connect the approved construction and its component breakdown with material specifications, colour versions and available supplier documents, then coordinate suitable testing where evidence is missing. Two colourways may share the same board but use different printed wraps. Identifying that difference helps focus the assessment on what changed while retaining relevant evidence for unchanged materials.
Concentration and migration answer different questions
The 100 mg/kg restriction concerns the concentration present in the packaging or component. Migration testing asks how much of a substance moves from a material into food or a test medium under defined conditions, such as a particular temperature and contact time. A low migration result therefore cannot, on its own, establish a low concentration within the packaging material.
For food-contact packaging, composition evidence and applicable food-contact testing may both be relevant. For a jewellery or skincare gift box, the four-metal limit still matters even where food-contact testing has no role. When reviewing a report, look at what was measured and against which criterion: the presence of the word “lead” in a migration table does not make it a result for the PPWR concentration limit.
Hexavalent chromium is one form of chromium
The fourth entry in the legal sum is hexavalent chromium, written as Cr(VI). “Hexavalent” identifies a particular chemical state. A total-chromium result includes chromium in other states as well, so a report labelled simply “Cr” needs interpretation before it is used for the four-metal assessment.
Total chromium can provide a conservative screen because the amount of Cr(VI) cannot exceed the amount of chromium overall. If lead, cadmium, mercury and total chromium together are sufficiently low, a suitable analytical method may provide useful evidence without distinguishing chromium’s forms. If that conservative sum exceeds 100 mg/kg, however, the result alone does not show how much is Cr(VI). The laboratory can explain whether further analysis that distinguishes Cr(VI) is needed. The method’s suitability and sensitivity remain part of that judgment.
Read the result alongside the sample description
A report headed “packaging box” may contain results for several submitted parts, or for one prepared sample. The heading alone cannot tell you which. To understand its value for the box you are buying, look for four connections:
- The sample and your specification. Descriptions, photographs or sample codes should identify the assessed components and connect them to the relevant construction, material and colour version.
- The sample and its preparation. Establish which constituents were included, whether components were assessed separately or mixed, and what the reported concentration represents. A mixed result needs an explanation of how it supports conclusions about the relevant components.
- The results and the criterion. Check the four named substances, units and combined assessment against 100 mg/kg. Clarify whether a chromium entry means total chromium or Cr(VI).
- The method and the material. The laboratory should be able to explain why its methods and reporting limits suit the submitted paper, coating, plastic, fabric or other material.
“Not detected” describes the result relative to the laboratory’s stated detection or reporting limit. It is not proof of absolute zero. Where one or more entries are reported this way, the report or laboratory explanation should make clear how those entries were treated in the combined assessment.
For a result close to 100 mg/kg, the laboratory’s decision rule also matters: this is the basis it uses to turn measurements, including their uncertainty, into a conformity statement. A rounded number can conceal that detail. Asking for the explanation is more useful than independently turning a borderline result into an unqualified pass.
Specific derogations do not create a general recycled-material allowance
The European Commission’s packaging page lists heavy-metal derogations for glass packaging and for plastic crates and pallets. Their use depends on the conditions of the relevant legal decisions. These provisions are specific to those packaging formats; they do not provide a general allowance for recycled paper boxes or recycled-plastic inserts. For an ordinary printed rigid box and its removable insert, use the 100 mg/kg combined ceiling as the assessment criterion.
Keep the evidence connected to the packaging you order
An earlier heavy-metal report may still contribute useful evidence because the numerical ceiling has carried forward. Its usefulness depends on how well the tested sample represents the current packaging. A change of insert supplier, printed colour, coating or material formulation can change that relationship. Review the affected evidence when the specification changes, rather than assuming either that an old report covers every future version or that its date makes all its information unusable.
A passing four-metal assessment supports this particular composition requirement for the packaging or components covered. Recyclability, other applicable substance restrictions and the wider conformity documentation require their own supporting evidence. Our guide to PPWR testing and reports for paper packaging explains how these documents fit together.
If you are developing packaging for EU sales, you can discuss the project with us using a sample or drawing, the intended material and colour variants, and any existing reports. We can help connect those records to the proposed construction and coordinate additional evidence where it is needed—so your team can see how the results support the finished components it has approved.
