Why The Overall Migration Limit (OML) Testing is of Critical Importance in Food Safety

Food contact materials, such as plastics, rubber, ceramics, and metals, can release chemical substances into food during contact, posing potential food safety risks. Overall Migration Limit (OML) testing is a crucial indicator for assessing the safety of these materials. Its significance is highlighted in several key areas:

Protecting Consumer Health

OML testing quantifies the total amount of non-volatile substances that migrate from the material into food. This helps prevent health risks such as chronic poisoning, cancer, and birth defects that could result from excessive levels of harmful substances (e.g., plasticizers, heavy metals, monomer residues). For instance, if phthalate plasticizers from plastics migrate into food, they could disrupt the human endocrine system.

Ensuring Regulatory Compliance

Major global markets have established strict OML limits for food contact materials:

Ÿ   European Union (EU): According to Framework Regulation (EC) No 1935/2004 and specific directives (e.g., (EU) No 10/2011), the OML is typically 10 mg/dm² or 60 mg/kg (calculated using food simulants).

Ÿ   China (GB): The GB 4806 series of standards, such as GB 4806.7-2016 (plastics), specifies an OML of 10 mg/dm².

Ÿ   United States (FDA): Through 21 CFR Parts 170-189, the FDA regulates indirect food additives (including migrants), with some scenarios requiring OML to be ≤ 50 mg/kg.

Enhancing Product Competitiveness

Obtaining an OML test report certified by authoritative bodies (such as SGS or Intertek) can increase consumer trust and help brands enter high-end markets.

Methods for Determining Overall Migration Limit in Food Contact Materials

OML testing simulates real-world contact between the material and food. It involves extracting migrating substances using food simulants and then performing quantitative analysis. Based on relevant standard test methods, common procedures and steps include:

1、 Selection of Food Simulants

The appropriate food simulant is chosen based on the type of food the material is expected to contact:

Ÿ   Aqueous foods (e.g., drinking water, fruit juice): Distilled water or 3% (w/v) acetic acid solution.

Ÿ   Acidic foods (e.g., vinegar, ketchup): 3% (w/v) acetic acid solution.

Ÿ   Alcoholic beverages (e.g., beer, wine): 10% (v/v) or 20% (v/v) ethanol solution.

Ÿ   Fatty foods (e.g., cooking oil, chocolate): Vegetable oil (e.g., olive oil) or isooctane.

2、 Migration Experiment Conditions and Preparation of Food simulant

Pre-treatment for migration tests requires a migration test cell that meets standard requirements. Food simulant for migration tests should be prepared according to relevant standards, at specified temperatures and times, based on food contact conditions.

Common Instruments for Overall Migration Limit Testing

Overall Migration Limit and Non-Volatile Residue Analyzer: This highly integrated and automated instrument efficiently measures migration and non-volatile residues. It's widely used for

Ÿ   Measuring migration in various food contact materials and products.

Ÿ   Determining non-volatile residues in pharmaceutical packaging materials.

Ÿ   Similar physicochemical measurements for food, food additives, and pharmaceuticals.

Through innovative integrated technology, this system combines the core experimental steps of traditional evaporation residue detection—evaporation, drying, and constant weight weighing at room temperature—into a single unit. This completely changes the traditional method where experimenters frequently operate separate devices like evaporation dishes, constant temperature water baths, electric ovens, and analytical balances. It significantly reduces manual operation intensity and effectively controls test errors caused by manual operations, markedly improving the repeatability and reproducibility of detection data.

In conclusion, overall migration limit testing is the cornerstone of food contact material safety assessment. By simulating actual use conditions, it quantifies the total amount of chemical substances migrating from materials into food, ensuring product compliance with regulations and safeguarding consumer health. Detection requires strict adherence to standard methods (e.g., GB 31604.8, ISO 10993-17) and relies on high-precision instruments (e.g., migration cells, overall migration limit and non-volatile residue analyzers) to achieve reliable results. For businesses, establishing a comprehensive overall migration limit testing system is not only a regulatory requirement but also key to enhancing product competitiveness and mitigating market risks.

Labthink is committed to helping customers deal with packaging problems through the improvement of packaging testing technology and the research and development of testing instruments, and helping the quality and safety of packaging related industries. For more information, please visit www.labthink.com, or contact us via trade12@labthink.com.