Overview
ISO 15267:1998 specifies a qualitative flashpoint limit test for animal, vegetable and marine fats and oils using the Pensky‑Martens closed‑cup flash tester. The method determines whether a sample at a given temperature will produce a flash when exposed briefly to a test flame. It is intended to support safety assessment, product classification and transport regulatory decisions.
Key Topics
- Scope: Applicable to animal, vegetable and marine fats and oils; small amounts of volatile solvents may be present.
- Principle: The sample is heated at a slow, controlled rate with stirring; when the test temperature is reached a small flame is introduced into the closed cup. A sample is deemed to have "flashed" if a large flame propagates across the surface (blue halo ignored).
- Apparatus: Pensky‑Martens closed cup tester per ISO 2719, thermometer (range 10–200 °C or IP 101 C), swing‑type centrifuge and 120 ml centrifuge tubes with stoppers.
- Preparation: Follow ISO 661 for test sample preparation. If solid at room temperature, melt slowly not higher than 5 °C above the melting point. Treat roughly 90 g sample with 5 g anhydrous sodium sulfate, shake, stand and centrifuge to obtain clear oil for testing.
- Procedure highlights:
- Fill cup to the marked line and suspend thermometer so bulb is 43–46 mm below the cup rim.
- Adjust test flame to ~4 mm diameter.
- Heat at 5–6 °C per minute with stirring at 1–2 revolutions per second.
- At the specified temperature (commonly 121 °C) stop stirring and lower the test flame within 0.5 s; observe for a distinct flash.
- Perform tests in duplicate; use fresh portions for determinations at different temperatures.
- Reporting: Report either "flash" or "no flash" at the specified temperature and state the method and apparatus used. If duplicates disagree, disregard the "no flash" result.
Applications
- Safety testing: Rapid assessment of whether a fat or oil will flash under specified conditions for workplace or process safety.
- Classification: Supports classification decisions for storage, handling and transport of fats and oils when flash behavior at a defined temperature is required.
- Quality control: Useful as a go/no‑go test in production and incoming material inspection where presence of volatile contaminants is a concern.
Related Standards
- ISO 2719 - Pensky‑Martens closed cup method for petroleum products and lubricants (apparatus details).
- ISO 661 - Preparation of test sample for animal and vegetable fats and oils.
- ISO 5555 - Recommended sampling for animal and vegetable fats and oils.
Notes: Annex A of ISO 15267 is informative and summarizes an interlaboratory trial organized by FOSFA and NOFOTA in 1995. For precise implementation, refer to the full ISO text and referenced standards to ensure compliance with current editions.