Overview
ISO 16532-1:2008 - "Paper and board - Determination of grease resistance - Part 1: Permeability test" - specifies a laboratory method to measure the grease resistance (grease permeability) of paper and board. The test establishes the break-through time (actual penetration) and, optionally, show-through time (visual spotting) by applying a dyed simulated fat (standard palm kernel oil) to test pieces and timing penetration through the sheet. The method applies to food board, greaseproof and vegetable parchment, sized or coated papers, and materials made grease resistant by extrusion coatings. Tests may be performed on creased or uncreased samples.
Key Topics and Requirements
- Test principle: Apply a controlled volume of dyed palm kernel oil through a template onto the sample with a defined weight; observe underside staining (break-through) or surface spotting (show-through).
- Standard grease: Palm kernel oil specified by liquefaction temperature (27–29 °C), dynamic viscosity at 35 °C (33.5–35.0 mPa·s), refractive index at 40 °C (1.44–1.45) and dyed with 0.25% Sudan red (or equivalent fat‑soluble dye).
- Apparatus: glass plate with mirror, cellulose wadding, metal template (≈30 mm hole), weights (50–55 g), metal rings, stopwatch, creasing apparatus (Annex A).
- Sampling & conditioning: Samples selected per ISO 186; condition tests at 23 °C ±1 °C and 50 % ±2 % RH (per ISO 187). Minimum of 10 determinations per side (20 if both sides tested).
- Observation intervals: Frequent checks (every 1 min for first 10 min, then progressively longer intervals up to a final 24 h inspection) are prescribed.
- Results reporting: Express mean and range for break-through / show-through times using defined rounding intervals; include full test conditions and reference to ISO 16532-1.
- Precision: No definitive interlaboratory precision statement available due to subjective observation challenges.
Applications
- Quality control and specification of food packaging papers, greaseproof board, and coated substrates where prevention of oil/grease permeation and spotting is critical.
- Verification of internal sizing, surface treatments or extrusion coatings intended to impart grease resistance.
- Comparative testing during material development, supplier qualification, and production acceptance testing.
Who Uses This Standard
- Paper and board manufacturers and converters
- Packaging designers and food-packaging engineers
- Independent testing and materials laboratories
- Regulatory and compliance teams concerned with food-contact packaging performance
Related Standards
Keywords: ISO 16532-1:2008, grease resistance, paper and board, permeability test, break-through time, show-through time, palm kernel oil, food packaging, greaseproof paper.
