Migration

Substance migration in the Packaging Industry

Substance migration is a critical process in the interaction between packaging and its contents, characterized by the transfer of chemical compounds between two contacting mediums. This phenomenon, driven by molecular diffusion and thermal agitation, plays a crucial role in the packaging industry, especially when it comes to packaging liquid food products where the interaction between the liquid and the solid (container wall and content) is inevitable.

Categorization of migration:

1. Global Migration: This refers to the total amount of migrating substances, measured in mg/kg of foodstuff or mg/dm² of material, without distinguishing individual components.

2. Specific Migration: In contrast, specific migration focuses on the quantity of a single identified compound, whether it's a simple or combined compound, moving from one surface to another.

Regulation and Control:

Current regulations tend to prioritize the assessment of specific migration for better risk management concerning human health and the environment. This regulatory approach is crucial for monitoring substances such as additives, monomers, or potential contaminants like plasticizers (e.g., DEHP) or bisphenol A (BPA), whose migration is strictly regulated.

Influential Factors:

Several factors influence migration in food packaging:

- Chemical composition of migrating substances
- Ambient and content temperatures
- Duration and contact conditions
- Contact surface
- Composition of packaging materials

Understanding these elements is essential for developing safe packaging that complies with public health standards.