The 60-second answer
- The risk in a food-packaging label is not whether the ink is "toxic" — it is how much unreacted material can reach the food. The three usual sources are photoinitiators, residual monomers, and mineral oil.
- Paper labels and cartons fail mostly by set-off: under reel or stack pressure the printed face presses residues onto the reverse side, which is the side that later meets the food. A barrier film stops permeation; it does not stop set-off.
- Four things are under your control: a food-packaging-compliant (low-migration) ink, a thin ink film (total deposit at or below 2 g/m²), full cure inside a defined speed–dose window, and cooling plus controlled stack pressure after printing.
1. Three terms that get mixed up
When a buyer asks "is your ink food grade?", three different questions are usually bundled together. Separate them and you know what to ask the supplier for, and what to test.
| Route | How it happens | Paper / board | Film | Control |
|---|---|---|---|---|
| Through migration | Substances pass through the substrate itself, from the printed face to the other side, then into the food | High risk (porous, fibrous) | Depends on structure; PET and PA are good barriers, PE less so | Barrier substrate, ink load, cure |
| Set-off | The printed face presses unreacted residues onto the reverse side under reel or stack pressure; usually invisible, only molecules move | The dominant route | Also happens on reels and linerless stock | Cool the web, control tension and stack pressure, interleaving, low-migration ink |
| Gas phase | Volatile components evaporate from the print into the headspace and condense on the food | Very visible on dry foods (cereal, flour) | Depends on headspace and storage temperature | Low-volatility formulations, avoid hot storage |
Why labels deserve particular care: labels are printed, stored and shipped in rolls, and the pressure between laps is exactly what set-off needs. And because the label sits on the outside of a pack, it looks as if there is no contact — while the inside face of that pack is the surface that touches food.
2. The regulatory map: which document covers what
| Rule / document | What it covers | What it means for a label |
|---|---|---|
| (EC) No 1935/2004 | Framework for food contact materials: no transfer of constituents in quantities that endanger health or unacceptably change the food; Article 17 requires traceability | Applies to all food packaging, including indirect contact; batch and printing records must be retrievable |
| (EC) No 2023/2006 | Good manufacturing practice for food contact materials | Only food-packaging auxiliaries on the press — reducers, wash, varnish, adhesive |
| (EU) No 10/2011 | Specific migration limits (SML) and overall migration for plastics | Used by analogy for the plastic layers of laminates; benzophenone, for example, has an SML of 0.6 mg/kg |
| Swiss SR 817.023.21, Annex 10 | The first statutory positive list for printing inks: Part A evaluated substances with limits, Part B non-evaluated, detection limit 10 ppb (0.01 mg/kg) | The de facto common yardstick for ink compliance; after the 2024 revision non-listed substances must be non-CMR and migrate below 10 µg/kg, with a transition ending in January 2026 |
| German Printing Ink Ordinance (GIO) | Positive list on the same model | Transition ended January 2026; German-speaking buyers often specify it directly |
| EuPIA GMP guideline and Charter | Industry manufacturing and raw-material standard | The document to ask an ink supplier for when you request a compliance statement |
| Brand-owner guidance (e.g. Nestlé Guidance Note) | Brand-specific packaging ink requirements | Usually stricter than legislation; read it before choosing a formulation |
| Singapore SFA / Malaysia Food Regulations 1985 / Indonesia BPOM | Local food contact and labelling requirements | Generally framed as "must not endanger health"; lists and test packages differ — confirm with your importer |
A second track on the packaging side: the sum of lead, cadmium, mercury and hexavalent chromium must not exceed 100 mg/kg (Directive 94/62/EC, Article 11). From 12 August 2026 Regulation (EU) 2025/40 replaces it, keeps the 100 mg/kg limit and adds PFAS limits for food-contact packaging (next section).
3. Four substance groups buyers ask about
| Substance | Where it comes from | Why it is questioned | Numbers that matter |
|---|---|---|---|
| Photoinitiators (benzophenone, ITX) | Molecules in UV inks and varnishes that were never activated or reacted | Small and volatile; they move through paper within hours. ITX migrating from a UV offset carton into baby milk in 2005 was the turning point for the industry | Benzophenone SML 0.6 mg/kg; default 10 ppb for non-evaluated substances |
| Residual monomers and oligomers | Acrylate monomers and oligomers left behind by incomplete cure | Small molecules move; as a rule of thumb, above about 1,000 Da migration risk drops sharply | Under-cure means the molecules never joined the network |
| Mineral oil MOSH / MOAH | Conventional offset inks (mineral oil roughly 20–30% of the ink, of which MOAH 1–50%), adhesives, recycled fibre | Most visible on dry foods (cereal, flour, chocolate) with long contact; MOAH is the fraction under scrutiny for carcinogenic potential | BfR advice: virgin fibre, mineral-oil-free inks, a functional barrier; PET and PA work as barriers |
| Heavy metals and PFAS | Pigment impurities, recycled stock, grease-proof coatings | Hard limits that fail a shipment on the spot | Sum of four heavy metals ≤100 mg/kg; food-contact PFAS: 25 ppb any, 250 ppb sum, 50 ppm including polymeric (from 12 Aug 2026) |
4. Three ways a label meets food — three different risks
| Where the label sits | What touches the food | Main route | What to do |
|---|---|---|---|
| Outside the pack (bottle, can, carton, pouch) | Not the label itself, but the inner face of the pack | Through, set-off, gas phase | Compliant ink, controlled ink load, full cure; follow the brand owner's guidance where it exists |
| Inside the pack, or directly on the food (fruit stickers, bakery paper, seal labels) | The label itself | Direct migration | Only direct-contact-grade materials and inks; general offset inks are not suitable. The applicable list is confirmed by the buyer and their compliance adviser |
| Linerless, large stacks, roll-fed application | The reverse side, against food or inner packaging | Set-off, at its worst | Cooling, reel tension and stack pressure control, interleaving, low-migration ink first |
5. Six things you can actually control
- Ink selection: specify a food-packaging-compliant (low-migration) ink. The mechanism is molecular weight, not a secret formula — photoinitiators are themselves polymeric or carry acrylate groups so they react into the network, and monomers and oligomers are chosen high-molecular-weight and low-volatility.
- Print thinner: keep total deposit at or below 2 g/m². Full-bleed CMYK plus white plus two varnishes is simply more potential migrant per square metre.
- Cure fully: establish the speed–dose window on the densest colour, run inside it with a margin, and log lamp hours and radiometer readings — ageing lamps are the most common hidden cause.
- Cool and control pressure: cool before rewinding or stacking; manage stack pressure and reel tension. This is the cheapest set-off control there is.
- Press hygiene: food-packaging auxiliaries only. One ordinary wash or reducer is enough to take a compliant job out of compliance.
- Look at the substrate: porous or recycled stock brings its own mineral oil and absorbs uncured ink. For low mineral oil, specify virgin fibre.
6. Three checks anyone can do on the floor
② Rub: ten rubs with an ethanol-soaked tissue on the print; colour on the tissue means under-cure.
③ Compare: keep a sample at ambient for 24–48 hours, then smell and rub it again against a fresh-off-press sheet. A large difference says the cure window is wrong.
7. If testing is required, how to arrange it
- Migration test: the finished article is exposed to the specified food simulants (aqueous, acidic, alcoholic, fatty) at set time and temperature, then tested for specific migration (SML) or overall migration.
- Set-off test: printed face pressed against unprinted face under load for a set period (commonly 10 days), then the unprinted side is tested. This is the test most often skipped and the one closest to how a reel actually behaves.
- Sensory test: odour and taint, frequently required by food brands.
What we can do: select materials to the standard and limits you specify, keep retention samples, and arrange third-party laboratory testing, with the report issued by the laboratory. The test package, limits and pass criteria are specified by you or your compliance adviser. Compliance determination sits with the brand owner and their advisers; we do not issue compliance declarations or decide which regulation applies to your market.
8. Three questions buyers ask us
Is there really a problem with ordinary offset ink on food packaging?
It depends on whether there is indirect contact with food, and on ink load and cure. A label on the outside of a pack is not forbidden — but it should use food-packaging-compliant ink, with controlled deposit and verified cure. Ordinary ink laid on thick, against a fatty product or long contact, is a materially higher risk. Most brand owners simply require compliant ink plus a test report, and that requirement usually matters more than a few cents per label.
Does a gloss or barrier film make it safe?
A film stops permeation through the substrate; it does not stop set-off. Residues on the printed face transfer to the reverse side under reel or stack pressure, and the reverse side is the one that meets food. A barrier is an addition, not an exemption — choose the ink first, then talk about barriers.
Can you supply a migration test report?
We can arrange third-party laboratory testing to the standard you name — the simulants and conditions of EU 10/2011, the Swiss list, a brand owner's guidance note — with the report issued by the laboratory. If your market only requires compliant ink plus a supplier statement, we can provide the ink supplier's compliance documentation and batch traceability. Tell us which one you need, and which tests, before production: discovering at the end that the report does not use your customer's pass criteria is an expensive way to learn it.
9. Six things to send with an enquiry
- Where the label sits — outside the pack, inside, or in direct contact with food — and the substrate;
- The food type (dry, fatty, acidic, alcoholic, frozen), the contact time and the storage temperature;
- Size, quantity, and whether it is supplied on rolls (core diameter and unwind direction);
- The destination market and the standard to be met (EU, Swiss list, brand-owner guidance, local rules);
- Whether a test report is needed, which tests, and who determines pass or fail;
- Artwork (AI or PDF, fonts outlined or embedded), spot colours and any barcode grade requirement.
Related reading: Choosing a label factory, Food labelling for Singapore, Malaysia and Indonesia, Allergen labelling in four markets, Labels for chilled and frozen food, Specifying a roll label.
Where to go next
- Artwork: AI, PDF, EPS or PSD with fonts outlined or embedded; include the die line if you have one; 20MB per file. A photo or screenshot is fine if the design is not final.
- Finished size and shape (round, square, custom; a die-line file is ideal).
- Quantity: how many versions, how many per version, and whether it ships in rolls or cartons.
- Material and where the label sits: paper, synthetic paper, PE or PET; outside the pack or inside.
- Destination market and the standard to meet (Hong Kong, Southeast Asia, EU food-contact rules).
- Required delivery date: samples and digital work about 24 hours, small runs about one week, bulk about 15 days — confirmed against the actual schedule.
Your contacts: quotations Ms Zeng +86 180 1199 6161 | sales Mr Hong +86 189 2511 1128. We reply within the working day (Monday to Saturday); for urgent work please call.
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