Tenax Migration Testing Parameters for Recycled Packaging Hydrocarbon Verification
Modified solid simulant Tenax TA testing under EN 14338 verifies gas-phase MOSH and MOAH migration from recycled paperboard without false-positive wax interference.
Gas Phase Partition Coefficient
Thermodynamic Ratio
The equilibrium concentration of a volatile compound in the vapour phase relative to its concentration in a solid or liquid substrate determines its migration potential. In paperboard packaging, the gas phase partition coefficient governs how volatile organic compounds move from the recycled fibres into the air space inside the box. This value helps calculate whether contaminants will easily evaporate from the board and settle onto the packaged goods.
Substrate Interaction
Higher values of this index indicate that a compound prefers to remain in the gas phase rather than bind to the cellulose fibres of the board. Conversely, strongly bound chemicals have low coefficients and remain trapped within the paper matrix, posing less risk of rapid migration. Temperature increases always raise this value, accelerating the release of volatile substances from the board and into the internal packaging atmosphere.
Analytical laboratories measure this ratio by enclosing board samples in sealed vials, heating them to a set temperature, and analyzing the headspace gas.
Safety Prediction
Packaging engineers use these equilibrium values to design effective barrier coatings that slow down the transport of harmful mineral oils. If a compound shows a high propensity to enter the gas phase, the outer barrier must possess high resistance to prevent contamination of the food product. This ratio guides the choice of barrier polymer, ensuring that the package maintains food safety throughout its entire expected shelf life.