MOSH and MOAH contamination in tea packaging is one of the least understood compliance risks in the co-packing industry. The tea itself is rarely the source. The contamination enters through the materials around it: outer cartons made from recycled board, jute transport bags, printed paper tags, and some film envelopes. EU food safety authorities and German retailers have issued benchmarks. Your buyers are testing against them.

This guide explains what MOSH and MOAH are, where they come from in a tea bag production chain, what the PT-2.33 envelope material choice means for your MOSH risk profile, and what buyers expect to see in your compliance documentation.

What MOSH and MOAH are

MOSH (Mineral Oil Saturated Hydrocarbons) are complex mixtures of saturated alkanes derived from mineral oil. They accumulate in body fat and liver tissue. Long-chain MOSH (C25+) accumulate more readily and persist longer.

MOAH (Mineral Oil Aromatic Hydrocarbons) are polycyclic aromatic compounds in the same mineral oil fraction. Some are genotoxic and potentially carcinogenic. MOAH is the higher-concern fraction because unlike MOSH, there is no established safe intake threshold.

The two fractions are always analyzed together. EU regulatory work has been running under EFSA since 2012. Germany's Federal Institute for Risk Assessment (BfR) was first to set practical guidance values for food contact materials and food. The European Commission has been working toward binding regulation; in the interim, BfR guidance and retailer-driven specifications fill the gap.

EFSA opinions and BfR guidance values

EFSA published a comprehensive risk assessment of mineral oil hydrocarbons in food in 2012 (EFSA-Q-2011-00565) and updated its position in subsequent opinions. The key findings:

• MOSH above C16-C35 accumulate in liver, spleen, and lymph nodes with no established safe daily intake
• MOAH with three or more aromatic rings are potentially genotoxic with no acceptable exposure threshold
• Food contact materials (packaging) are a primary migration pathway

BfR Germany issued technical guidance (BfR Opinion 016/2012 and subsequent updates) establishing practical limits for food contact materials. The recommendation for MOAH in food is effectively "as low as reasonably achievable," with BfR flagging any MOAH above 0.5 mg/kg in food as requiring action.

Belgian retail chains (Colruyt, Carrefour Belgium) and German discounters (Aldi, Lidl) have translated BfR guidance into supplier specifications with defined ceilings. These are the numbers your buyers use in audit questionnaires.

Sources of contamination in a tea bag production chain

Understanding where MOSH and MOAH enter the chain is the first step to controlling them.

Recycled cardboard outer cartons. This is the dominant source for tea products. Recycled paper and board contains mineral oil from printing inks used in the previous product lifecycle. The MOSH and MOAH migrate from the carton through the outer envelope and into the tea bag. This migration can occur without direct contact - gas-phase transfer through headspace is documented in BfR studies.

Jute transport bags for raw herbs. Jute is treated with batching oil (mineral oil-based) during fiber processing. Raw herb deliveries arriving in jute sacks carry MOSH into the production environment. The contamination transfers to herbs and from herbs to the finished tea bag.

Ink-printed paper tags. Conventional printing inks (especially offset inks) contain mineral oils as solvents and carriers. The string + paper tag assembly on the PT-2.33 bag runs directly against the tea bag surface during production. Offset-printed tags without mineral-oil-free ink certification are a confirmed MOAH pathway.

Lubricants in the bagging machine. Food-grade lubricants on the PT-2.33 are MOSH-free by specification (NSF H1 or equivalent). Non-food-grade lubricant use in tea bagging machines is a documented contamination source - it is not the case here, but it is something to verify when auditing any co-packer.

How envelope material choice affects MOSH risk

The PT-2.33 machine runs four envelope material types: OPP (oriented polypropylene), cellophane, PLA (polylactic acid), and paper. Each has a different MOSH/MOAH risk profile.

OPP (oriented polypropylene): MOSH from polymer processing and antioxidants are a documented concern in plastics. OPP migration into food is lower than paper but not zero. Plastics additives (polymer degradation products) can appear in the MOSH fraction. UV-printed OPP envelopes with UV-cured inks have significantly lower MOAH risk than solvent-based alternatives - UV inks do not use mineral oil solvents.

Cellophane: A regenerated cellulose film. Cellophane itself has very low MOSH contribution. The primary risk comes from the printing inks used on cellophane envelopes and from the outer carton migration pathway. Cellophane is gas-permeable, making it more vulnerable to vapor-phase MOSH transfer from outer packaging.

PLA (polylactic acid): Bio-based film. PLA has the lowest inherent MOSH contribution of the four envelope types and is not processed with mineral oil additives. The limiting factor is outer carton migration. PLA + mineral-oil-free ink printing + functional barrier board outer = lowest MOSH exposure pathway.

Paper (envelope wrap): Highest MOSH risk because paper fiber itself can carry mineral oil from its own production chain, and paper provides no migration barrier against outer carton contamination. Paper envelopes for EU retail distribution require functional barrier verification or independent MOSH/MOAH testing per lot.

Testing methods: what LC-GC and online HPLC mean

MOSH/MOAH analysis requires specialized analytical methods. Not all food labs offer them.

Online HPLC-GC-FID (High Performance Liquid Chromatography coupled with Gas Chromatography and Flame Ionization Detection) is the current standard method for MOSH/MOAH quantification in food. The method separates the MOSH and MOAH fractions by HPLC, then quantifies each by GC-FID. It can detect MOSH at 0.1 mg/kg and MOAH at 0.05 mg/kg in food matrices.

LC-GC-MS (with mass spectrometry detection) provides structural identification alongside quantification. This is required when a buyer wants compound-specific data rather than total MOSH/MOAH figures.

A valid MOSH/MOAH test report includes:

• Method reference (EN 16995:2017 or equivalent)
• Laboratory accreditation number (ISO/IEC 17025)
• Sample preparation details (extraction solvent, clean-up procedure)
• Quantified MOSH and MOAH separately by carbon chain length group
• Limit of quantification (LOQ) for each fraction
• Chain length distribution (to identify the accumulating fractions C16-C35 and C25+)

Ask any co-packer presenting a MOSH/MOAH COA whether the report includes chain length distribution. A report showing only total MOSH and total MOAH without chain length data does not meet German retailer audit requirements.

What buyer audit questionnaires ask

Tea buyers sourcing from co-packers increasingly include MOSH/MOAH in annual supplier questionnaires. The standard questions:

1. Do you test finished product for MOSH and MOAH? (Yes/No, and which lab?)
2. What is the MOSH C16-C35 result from the most recent production lot?
3. What is the MOAH result?
4. What outer packaging material do you use, and has it been tested for MOSH migration potential?
5. Are print inks on tags and envelopes certified mineral-oil-free?
6. How do you prevent jute bag contamination in raw material intake?

At Balkan Tea, the answers are documented by lot. Our intake protocol quarantines raw herbs that arrive in jute packaging until they pass MOSH spot-testing. The PT-2.33 runs with NSF H1 lubrication. Our tag supplier provides ink certification on request.

MOSH/MOAH and the German market

Germany is the strictest MOSH/MOAH market in the EU. BfR guidance has been applied by German retail buyers (both discounters and branded retail) since 2014. The German Food Federation (BLL/BVE) publishes sector-specific guidance that most German buyers incorporate by reference into their supplier codes.

For Balkan Tea, supplying the German market has been part of our operation since 1990. Herb exports to German buyers in the 1990s and 2000s predated formal MOSH regulation, but the family business already controlled jute-bag contamination because German buyers flagged off-flavors in herbs packed with conventional jute. The discipline that started as flavor management became the foundation for MOSH management when regulation arrived.

Tea brands launching into German retail via our full production service receive MOSH/MOAH documentation as part of the standard compliance package alongside pesticide MRL results. The package satisfies both regulatory requirements and typical German retailer audit criteria.

See also: Tea pesticide MRL limits EU buyers enforce, EU tea labeling rules, IFS vs BRC certification for tea, our bag specifications.

For MOSH/MOAH compliance questions on a specific project, contact us via the form below. Our technical team will confirm envelope material options and available test documentation for your target market.