Mineral Oil in Recycled Fiber Food Packaging: What MOSH and MOAH Mean

Par Leo Chan  | Rédacteur, BonitoPak | Plus de 20 ans d'expérience dans le domaine des emballages en pâte moulée

MOSH and MOAH are mineral oil fractions that migrate from packaging into food. Recycled paper and board are the most critical source, because mineral oil printing inks enter the recycling stream. EU maximum levels for MOAH take effect from January 2027.

Mineral oil in food packaging is the least discussed risk in the fiber category and the one with a date attached. It also sits awkwardly for anyone selling recycled fiber, because recycled content is normally the environmental selling point and here it is the source of the problem.

This article covers what these substances are, why recycled fiber carries the risk, what changes in 2027, and what can actually be done about it.

What MOSH and MOAH Actually Are

Mineral oil hydrocarbons split into two fractions, and the distinction matters because they behave differently in the body.

The sharper concern sits with MOAH. Species with three or more aromatic rings and limited alkyl substitution have been associated with potential genotoxic and carcinogenic effects. MOSH is judged of lower immediate concern but accumulates in tissue over time, and long term effects remain uncertain. Background on both is set out by the Food Packaging Forum.

Where It Comes From in Recycled Paper Food Contact Materials

The pathway is specific and it explains why recycled fiber is singled out.

Mineral oil based printing inks have long been used in newspapers. Newsprint enters the paper recycling stream. Pulping does not remove those oils, so they carry through into recycled paper and board, and from there they can migrate into whatever the packaging contains.

European risk assessment identifies recycled paper and board packaging as the most critical source of mineral oil in food, contributing significantly to dietary exposure, particularly where no effective internal barrier is present. Reported migration has been substantial: MOSH commonly in the range of several milligrams per kilogram of food, exceeding 100 mg/kg in some cases, with MOAH usually lower but occasionally above 10 mg/kg.

Other sources exist, including adhesives, hot melts, machine and hydraulic oils, and jute or sisal transport bags. But recycled paper food contact materials are the ones that draw regulatory attention.

EU MOAH Regulation: What Changes in 2027

The European position has been developing for over a decade and is now converging on binding limits.

Exceeding the indicative MOSH levels will not automatically remove a product from the market, but it should trigger investigation into the source of contamination. Indicative MOSH levels run from roughly 1 to 50 mg/kg depending on the food category. The regulatory position is tracked in detail by AGRINFO, and it is worth checking directly rather than relying on any summary, including this one.

Some national positions already go beyond the EU MOAH regulation. Switzerland prohibits recycled paper and board in direct contact with food outright, and German draft rules have proposed a specific migration limit for MOAH alongside a requirement for functional barriers.

The US and EU Positions Diverge Sharply

This matters for anyone exporting, and it catches buyers who assume compliance is universal.

In the United States, mineral oil hydrocarbons are permitted as direct and indirect food additives under specific regulations, with technical white mineral oil allowed as an indirect additive across a range of food contact materials. There is no equivalent to the incoming EU maximum levels.

So the same carton can be compliant in one market and a problem in another. A producer selling domestically in the US faces little regulatory pressure today. A producer selling into the EU, or supplying a retailer that applies EU standards globally, faces a hard deadline. Large retailers increasingly apply the stricter standard across their whole supply base rather than managing two specifications.

Why Recycled Fiber Carries the Mineral Oil Migration Risk

The underlying issue is control over inputs rather than anything about fiber itself.

A virgin fiber producer controls what enters the process from forest to finished pulp. A recycled fiber processor works with whatever the waste stream delivers, and that stream changes continuously. Yesterday’s input might be clean office paper and today’s might carry a higher proportion of newsprint. Neither the processor nor the customer controls that composition.

Which leads to an uncomfortable point worth stating directly. Recycled content is usually presented as the environmentally superior choice, and for carbon footprint and material recovery it generally is. For food contact contamination risk specifically, it is the weaker option. Both things are true at once, and a buyer choosing recycled fiber for food contact should do so knowing the trade rather than assuming recycled is better on every axis.

Does This Apply to Egg Cartons?

Less directly than to a dry food carton, and not zero.

An egg sits in its shell, so there is no direct contact between the fiber and the edible portion in the way there is with cereal or flour in a recycled board box. That reduces the migration pathway substantially and is why egg packaging has not been a focus of the regulatory work.

The qualifier is that eggshells carry thousands of pores and readily take up airborne molecules, and yolk fat is an effective solvent for exactly this class of compound. Extended storage in a closed pack is the condition where transfer is most plausible. It is the same physics we describe in our article on why some egg cartons smell, applied to a different substance.

The honest summary is that the risk is lower than for direct contact packaging and has not been quantified for shell eggs specifically. For a producer selling into the EU or supplying a retailer with its own standards, it is still a question worth being able to answer.

Four Ways to Reduce Mineral Oil in Food Packaging

• Virgin fiber. Removes the recycling stream as an input. Highest cost and weakest environmental story.
• Functional barrier. A layer between fiber and food that blocks mineral oil migration. Effective, but it adds a second material and compromises recyclability and compostability claims.
• Feedstock control. Sourcing recycled input that excludes newsprint and high ink loads. Reduces rather than removes risk, and depends on supplier discipline.
• Testing. Establishes what you actually have. Does not prevent anything, but it is how you find out before a customer does.

Note the tension in the second option. A functional barrier solves the migration problem and creates an end of life problem, because a fiber pack with a polymer barrier is no longer a single material item for recycling or composting. Where a brand is making environmental claims, that trade needs deciding deliberately.

On testing, detection limits sit below 0.1 mg/kg for most foods but are substantially higher in fatty products, where fat interferes with the separation step. If your product is fatty, discuss method suitability with the laboratory rather than assuming a standard test is sensitive enough.

Ce que nous observons sur notre propre chaîne de production

We manufacture molded pulp packaging in Chashan Town, Dongguan, using both recycled and virgin fiber systems, so this is a live question for us rather than an abstract one.

The material choice is application specific

We do not treat recycled fiber as the automatic answer for every product. Our produits à base de pâte à papier recyclée use a mechanical pulping process without chemical additives, which suits protective and transport applications well. Where a customer needs direct food contact into the EU, virgin or bleached systems are the more defensible starting point, and our pâte blanchie uses hydrogen peroxide rather than chlorine based bleaching.

Ask about feedstock, not just recycled percentage

Recycled content is usually quoted as a percentage, which tells you nothing about composition. A high recycled percentage sourced from clean converting waste is a different proposition from the same percentage sourced from mixed post consumer paper containing newsprint. That distinction is the one that matters here, and it is a fair question to put to any supplier.

Decide the barrier question before tooling

If a functional barrier is needed, it changes the specification rather than being applied at the end. It affects surface preparation, wall section and the end of life claim together. Our ligne de pressage à humide produces the smooth dense surface a barrier needs at roughly 0.7 to 1.2mm, while pressage à sec suits uncoated structural parts at 2.5 to 3.0mm. Sample molds run in about seven days and production molds around eight days after geometry approval, minimums from 1,000 pieces, with material options on our emballage de pâte à papier moulé sur mesure page.

What to Ask a Supplier

• What is the recycled feedstock composition, and does it include newsprint?
• Has finished product been tested for MOSH and MOAH migration, and can you see the report?
• Which laboratory method was used, and is it appropriate for a fatty food if that applies?
• Is a functional barrier available, and what does it do to recyclability and compostability?
• How is feedstock variability monitored between batches?
• Can virgin fiber be supplied for the products that need it?

Mise en pratique

Start by working out whether mineral oil in food packaging is a live risk for you. Direct contact with dry or fatty food, long storage, recycled board and an EU market together describe the high risk case. Shell eggs in a fiber carton sold domestically in the US sit at the other end. Most situations fall somewhere between, and knowing where yours sits tells you how much to spend on this.

If you are exposed, establish a baseline by testing, ask about feedstock composition rather than recycled percentage, and decide the barrier question deliberately because it trades against your environmental claims. If you are not exposed today but sell into Europe, the January 2027 date is close enough to plan against rather than react to.

Au BonitoPak we would rather have this conversation at specification stage than after a retailer audit, because the answer changes which fiber system a product should run on, and that is a decision made before tooling rather than after. Telling us the destination market and whether the pack is in direct food contact is the fastest route to the right recommendation.

À propos de l'auteur

Leo Chan is the writer of BonitoPak and has spent more than 20 years in molded pulp packaging, working with over 500 brands moving from plastic and foam to fiber based formats. BonitoPak manufactures molded pulp packaging at its facility in Chashan Town, Dongguan, Guangdong, running both wet pressing and dry pressing lines across six pulp systems, with in house mold design and tooling. The regulatory summary here reflects published European risk assessment and regulatory tracking as of mid 2026, alongside production experience on that line. Requirements are changing on a defined timetable and should be verified directly for your market and product. This is general information rather than legal advice.

Questions fréquemment posées

Q: Are mineral oil food packaging rules the same in the US?

A: The regulatory pressure is European. US rules permit certain mineral oils as direct and indirect food additives. Exporters and brands with EU customers face the tighter position, and retailers increasingly apply it globally.

Q: Is virgin fiber safer than recycled paper for food contact?

A: Not automatically, but the risk is far lower because inputs are controlled from forest to pulp. Contamination can still enter through inks, adhesives, machine oils or storage, so testing remains sensible.

Q: What is a functional barrier?

A: A layer between the fiber and the food that slows or prevents migration. It reduces mineral oil risk but adds a second material, which affects recyclability and compostability claims for the finished pack.

Q: Which foods are most affected?

A: Dry foods stored for long periods in direct contact with recycled board show the highest migration. Fatty foods absorb more readily, and fat also makes laboratory detection harder.

Q: Should I test every batch?

A: Test to establish a baseline for a supplier and feedstock, then periodically. Because the recycled waste stream varies continuously, a single clean result does not certify future production indefinitely.