EN 1104 Paper and Cardboard Intended for Contact with Foodstuffs - Determination of Transfer of Antimicrobial Compounds

The European standard “EN 1104 Paper and cardboard intended for contact with food - Determination of transfer of antimicrobial components” describes a method for determining the transfer of antimicrobial components from paper and cardboard materials and articles intended for contact with food. The necessity of using this standard may be determined by legal regulations concerning paper and cardboard intended for contact with food.

For the purposes of this standard, an inhibition zone refers to a distinct region around test specimens inoculated with a pre-selected test microorganism in a nutrient medium, where no growth occurs due to the release of water-soluble antimicrobial components. Evidence of the presence of an inhibition zone is the absence of test microorganism growth in a region (translucent zone) at least 2 mm wide at the edges of the test specimens.

In principle, a prepared nutrient medium is mixed with a suitable vaccine and poured into Petri dishes. Test samples are placed in the nutrient medium before it completely solidifies and then incubated. Upon completion of incubation, the presence of an inhibition zone is an indicator of the release of antimicrobial components. The test is performed with a bacterium called Bacillus subtilis and a fungus called Aspergillus niger. The result is based on visual assessment.

In an era where food safety is paramount, the materials used in packaging play a critical role in protecting consumers from potential contaminants. European standards offer rigorous guidelines to ensure that everyday items such as paper cups, cardboard boxes, and food packaging do not pose a health risk. One such standard, EN 1104, addresses a niche but vital concern: the migration of antimicrobial substances from paper and cardboard into food.

The EN 1104 standard provides manufacturers, regulators and laboratories with a standardized method for measuring and controlling this transfer, in compliance with broader EU regulations on food contact materials.

This standard reflects the increasing use of antimicrobials in packaging to extend shelf life and prevent bacterial growth. However, if proper controls are not in place, these substances can leach into food and potentially affect flavor, safety, and even human health. This standard ensures that innovations in antimicrobial packaging do not jeopardize consumer welfare.

Antimicrobial agents such as silver ions, quaternary ammonium compounds, or organic acids are increasingly being incorporated into paper and cardboard to prevent microbial contamination. This is especially true for products such as takeaway containers, fruit trays, or baking dishes where moisture and temperature can promote bacterial growth. However, the properties that make these materials effective barriers against microbes also raise concerns about unwanted migration during food contact.

The EN 1104 standard fills this gap by defining a test protocol to measure how much of these antimicrobial components migrate from the material to the food simulator under simulated usage conditions. This is crucial for compliance with EU Framework Regulation 1935/2004, which requires that food contact materials not endanger human health or unacceptably alter the composition of food. By offering a reproducible method, the EN 1104 standard helps prevent scenarios where trace amounts of antimicrobials could accumulate in the food chain, leading to antimicrobial resistance or allergic reactions.

In practice, the standard supports industries by enabling early detection of migration issues during product development. For example, a packaging manufacturer testing a new antimicrobial coated carton uses the EN 1104 standard to verify that migration levels remain below legal limits, thus preventing costly recalls or market rejection.

The EN 1104 standard essentially involves a migration test using food simulators to mimic real-world exposure. The process has a methodical structure that emphasizes repeatability and accuracy. The main steps of this process are as follows:

• Sample preparation: Samples are cut from paper or cardboard, usually into 10 cm x 10 cm squares. To standardize moisture content, samples are incubated at 23 degrees Celsius and 50% relative humidity for 24 hours. Antimicrobial components are identified through preliminary analysis (e.g., HPLC or GC-MS) to target specific migrations.
• Food-grade simulant selection: Simulants are chosen according to the type of food; distilled water for watery foods, 3% acetic acid for acidic foods, or 95% ethanol for fatty foods. Volume is typically 100 ml per 600 cm2 of material surface, providing a surface-to-volume ratio that reflects the usage.
• Migration simulation: The sample is brought into contact with the simulant in a sealed container. It is incubated at controlled temperatures (e.g., 40 degrees Celsius for 10 days) to simulate long-term storage, or at higher temperatures for shorter periods (e.g., 100 degrees Celsius for 30 minutes) for hot-filling applications. Periodic shaking is used to accelerate the transfer.
• Extraction and analysis: The simulant is separated from the sample and filtered if necessary. Antimicrobial transfer is measured using techniques such as spectrophotometry, chromatography, or microbial inhibition tests. Migration is calculated in mg/kg for the simulant or mg/dm2 for the material.
• Evaluation and reporting: Results are compared against specific migration limits set by regulations (e.g., 10 mg/kg for many antimicrobials). Uncertainties, detection limits, and compliance statements are reported.

The sensitivity of this method allows for the detection of low-level transfers (down to 0,01 mg/kg), making it suitable for both routine quality control and regulatory inspections.

In conclusion, the EN 1104 standard exemplifies how targeted standardization can increase trust in the food supply chain.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "EN 1104 Paper and cardboard intended for contact with foodstuffs - Determination of the transfer of antimicrobial components" standard.