Introduction: The Regulatory Significance of Petroleum Hydrocarbons
Mineral oil hydrocarbons (MOH) are among the most significant groups of chemical contaminants found in food-contact packaging materials, particularly in packaging made from recycled paper and cardboard. MOH can be divided into two main fractions: MOSH (Mineral Oil Saturated Hydrocarbons) and MOAH (Mineral Oil Aromatic Hydrocarbons). The European Food Safety Authority (EFSA) has scientifically demonstrated that MOSH can accumulate in the liver and spleen and lead to chronic toxicity; the MOAH fraction, on the other hand, poses genotoxic and carcinogenic risks, particularly with regard to its 3- to 7-ring aromatic components. Under the European Union’s Packaging and Packaging Materials Regulation (PPWR), controls regarding MOAH contamination in packaging that comes into contact with food are being further tightened, and clear obligations are being imposed on manufacturers in this regard. Nano-Test Labor Services performs MOSH and MOAH analyses in compliance with GLP principles using the internationally recognized LC-GC-FID technique and provides our customers with reliable quantitative data as well as an assessment of regulatory compliance.
Chemical Definition and Toxicological Profile of MOSH and MOAH
Mineral oil hydrocarbons are a complex mixture of numerous hydrocarbon compounds produced during the refining of crude oil. Depending on their chemical structure and toxicological properties, they are divided into two main fractions. The following table compares the chemical definitions, toxicological profiles, and typical sources of the MOSH and MOAH fractions in packaging:
| Property | MOSH (saturated mineral oil hydrocarbons) | MOAH (aromatic petroleum hydrocarbons) |
|---|---|---|
| Chemical Structure | Straight-chain (n-alkanes), branched (isoalkanes), and cyclic (cycloalkanes) saturated hydrocarbons | Hydrocarbons containing one or more aromatic rings; highly alkylated benzene derivatives and polycyclic aromatic compounds |
| Carbon number range | C10–C50 (typical analysis range: C10–C35 or C10–C50) | C10–C50 (typical analysis range: C10–C35 or C10–C50) |
| Toxicological Concerns | Accumulation in the liver and spleen (granuloma formation), chronic inflammation; classified by the EFSA as a “potential risk to human health” | 3- to 7-membered aromatic compounds can bind to DNA; Potential for genotoxic carcinogenicity; classified by the EFSA as a “high-priority health risk” |
| Typical source in packaging | Recycled paper/cardboard (newsprint inks), mineral oil-based process chemicals used in the production of virgin paper, printing inks, adhesives, wax coatings, and batch oils derived from jute and sisal fibers | |
Regulatory Framework and Applicable Limits
Although no legally binding specific migration limit (SML) for petroleum hydrocarbons has yet been established at the European Union level, various member states and the EFSA have published recommended thresholds and monitoring guidelines. The PPWR aims to close this regulatory gap and provides for stricter control of the presence of petroleum hydrocarbons in packaging materials.
Current Recommended Limits
The following table summarizes the current limit values recommended by various regulatory agencies and industry associations for MOSH and MOAH:
| Parameters | Reference / Source | Limit value (mg/kg of food or simulant) | Scope / Explanation |
|---|---|---|---|
| MOAH (C10–C35) | Federal Food and Feed Act (LFGB) / 22nd Amending Ordinance | 0.5 (not detectable) | Mandatory national limit for paper and cardboard that come into contact with food |
| MOAH (C10–C25) | German LFGB / 22nd Amendment Ordinance | 0.15 (not detectable) | Additional limit value specifically for the more volatile, low-molecular-weight MOAH fraction |
| MOSH (C10–C16) | EFSA/JRC Technical Report (2019) | 12 | Recommended threshold value for the MOSH fraction with low viscosity and high migration potential |
| MOSH (C16–C35) | EFSA/JRC Technical Report (2019) | Recommendations for Monitoring and Minimization | High-molecular-weight MOSH fraction; due to its potential to accumulate in the body, a reduction in exposure is recommended |
| MOAH (all political groups) | FoodDrinkEurope Packaging Guide | 0.5 (at the limit of detection) | A limit value voluntarily adopted by the industry; the goal is to achieve a level below the detection limit |
Note: The limit values listed above apply to materials that come into contact with food; the total concentration limits for the packaging itself may differ. Once the PPWR takes effect, harmonized, binding limit values are expected to be established at the EU level. Nano-Test continuously monitors developments in legislation and proactively informs its customers.
MOSH/MOAH Analysis Methods at the Nano-Test Laboratory
MOSH and MOAH analyses are an analytical process that requires a high degree of technical expertise and relies on the reliable separation and quantitative determination of complex hydrocarbon mixtures. At the Nano-Test laboratory, this analysis is performed using the internationally recognized reference method LC-GC-FID (liquid chromatography–gas chromatography–flame ionization detector).
LC-GC-FID System: Analytical Principle and Workflow
The LC-GC-FID method is a fully automated and highly precise analytical platform in which the MOSH and MOAH fractions are first separated using liquid chromatography (LC) and then each fraction is analyzed using gas chromatography (GC) and quantitatively determined with a flame ionization detector (FID). This method has been validated in accordance with the DIN EN 16995:2017 standard.
The following table describes the individual steps of the MOSH/MOAH analysis at the Nano-Test laboratory in detail:
| Step | Process | Technical Details |
|---|---|---|
| 1. Sample Preparation | Extraction | The packaging sample or migration simulant is extracted using a suitable organic solvent (hexane or an ethanol/hexane mixture). Appropriate internal standards (e.g., 5-α-cholan, perylene) are added to monitor the extraction yield and correct for matrix effects. |
| 2. LC Fractionation | Separation of MOSH and MOAH | The resulting extract is injected into a normal-phase LC column. The silica gel column allows the MOSH fraction (saturated hydrocarbons) to pass through but retains the MOAH fraction (aromatic compounds) in the column. The MOAH fraction is then eluted from the column by changing the composition of the mobile phase and transferred to the GC system. |
| 3. GC-FID Analysis | Quantitative Determination | The MOSH and MOAH fractions from the LC are transferred separately into the GC column. A temperature program is used to separate the hydrocarbons according to their carbon number. The FID detector is used to quantitatively measure all hydrocarbons. The MOSH and MOAH quantities are calculated based on the peak areas of the internal standards. |
| 4. Data Analysis | Fraction Integration and Reporting | In the chromatograms, the characteristic “humps” (insoluble complex mixture—UCM) of the MOSH and MOAH fractions, as well as the sharp n-alkane peaks above them, are integrated. The results are divided into different fractions based on carbon number (e.g., C10–C16, C16–C25, C25–C35) and reported in mg/kg. |
Quality Control and Method Validation
The reliability of the MOSH/MOAH analyses at the Nano-Test laboratory is ensured by a comprehensive quality control protocol. The following table summarizes the key quality control parameters applied during the analysis process:
| Quality Control Parameters | Application | Acceptance criterion |
|---|---|---|
| Blind Test | Mindestens 1 pro Analyseserie</ td> | MOSH und MOAH < LOQ; Überwachung der Laborkontamination |
| Recovery rate of the internal standard | Added to each sample (e.g., 5-α-cholestane, perylene) | 70–120% for the MOSH internal standard; 50–120% for the MOAH internal standard |
| Control standard (mineral oil mixture) | At least 1 in each series of analyses | Within ±20% of the expected concentration |
| Duplicate Analysis | 1 out of 10 samples in each group | Relative Percentage Deviation (RPD) ≤ 30% |
| Certified Reference Material (CRM) | If available, in each series | Within ±25% of the certificate value |
Nano-Test's Integrated Service Approach to MOSH/MOAH Analysis
At Nano-Test Labor Services, we do not offer MOSH and MOAH analyses as standalone tests, but rather as an integral part of the PPWR and food safety compliance process. Our service model consists of the following components:
| Service Component | Scope | Benefits for the Customer |
|---|---|---|
| Regulatory Consulting | Determining which fractions (C10–C16, C16–C25, C25–C35) need to be analyzed | Cost Optimization Through the Right Testing Strategy; Avoiding Missing or Unnecessary Analyses |
| LC-GC-FID Analysis | Quantitative Determination of MOSH and MOAH Using a Fully Validated LC-GC-FID System for the Quantitative Determination of MOSH and MOAH | Reliable and traceable results using the reference method recognized by regulatory authorities |
| Faction-Based Reporting | Breakdown and detailed presentation of the results by carbon number fractions (C10–C16, C16–C25, C25–C35) | Easier identification of the source of contamination (fresh fibers, recycled components, specific process chemicals) |
| Conformity Assessment | Preparation of a statement of compliance or non-compliance by comparing the results with applicable national limit values (e.g., the German LFGB) and industry recommendations, and issuance of a statement of compliance or non-compliance | A clear and definitive assessment of the product's legal status |
| Technical Documentation | Comprehensive, GLP-compliant analytical report and Declaration of Conformity (DoC) | Complete documentation for regulatory applications and customer audits |
For manufacturers that use packaging made from recycled paper and cardboard in particular, MOSH/MOAH contamination is one of the most critical aspects of supply chain management. At Nano-Test, we not only provide analytical data, but also offer our customers technical consulting regarding root cause analysis for detected contaminants, supplier evaluation, and functional barrier solutions.
To ensure that your packaging, which you export to the European market, complies with MOSH/MOAH requirements under the PPWR and related regulations, and to have your mineral oil hydrocarbon analyses performed by a reliable and experienced partner, please contact our team of experts to receive detailed information about Nano-Test’s accredited laboratory services and technical consulting.