Chemical Assessment
Gravimetric analysis quantifies the total mass of substances transferred from a food contact material into a food simulant under specified time and temperature conditions. Overall migration testing establishes a universal ceiling for the transfer of non-volatile compounds regardless of their individual toxicological properties. Regulators mandate this procedure to ensure that packaging substrates do not contribute harmful amounts of plasticizers, pigments, or monomers to the consumer goods they hold.
Materials that exceed the prescribed limit fail the compliance verification and remain unsuitable for direct food contact applications.
Analytical Procedure
Laboratories prepare samples by cutting squares or discs from the finished sheet or container to represent the functional surface area. Analysts then immerse these specimens in liquids like ethanol or acetic acid that model common fatty and acidic foodstuffs. High precision balances record the mass of the simulant before and after contact while controlling for environmental variables such as evaporation or surface absorption.
Operators calculate the difference in mass per square decimeter of the material surface to determine if the substrate performs within safety parameters.
Material Performance
Success depends on the inherent barrier properties of the base fiber and the chemical stability of any coatings applied during the converting process. Inadequate crosslinking in a polymer layer or high solubility in the chosen simulant leads to elevated mass transfer during the test window. Manufacturers select additives and resins based on their stability against chemical leaching to maintain structural integrity throughout the shelf life of the package.
Compliance remains a static metric that confirms the barrier prevents unintended chemical migration into the food supply.
