Chemical Structure
Synthetic organofluorine compounds containing fully fluorinated carbon chains exhibit exceptional oleophobic and hydrophobic properties when applied to paper substrates. Historical application of perfluoroalkyl substances in food packaging provided grease resistance and moisture resistance to fast food wrappers and bakery boards. The chemical class includes long-chain and short-chain fluorinated polymers applied at the wet end or size press during papermaking.
Bio-based barrier coatings and physical surface densification offer non-fluorinated alternatives for oil barrier packaging.
Barrier Action
Fluorinated carbon backbones create low surface energy barriers that repel both polar water molecules and non-polar lipid matrices. Treating paper stock with perfluoroalkyl substances prevents oil wetting and keeps liquids from penetrating cellulosic pore structures. Mechanical refining increases fibre contact to aid surface resistance.
Regulatory Restriction
Persistence in environmental water systems and potential human toxicity led global environmental agencies to restrict or ban fluorinated chemistry in food contact materials. Regulatory bodies enforce strict limits on perfluoroalkyl substances, targeting specific chemicals like perfluorooctanoic acid and perfluorooctane sulfonate. Paper mills transition to aqueous dispersion coatings or microfibrillated cellulose to achieve grease resistance without fluorinated compounds.
Test methods use total fluorine analysis or liquid chromatography tandem mass spectrometry to verify compliance. Non-contact industrial packaging grades fall outside these food safety prohibitions.
