Due to the increase in production and technical application of polyunsaturated plant oils, more high loss fires are caused by spontaneous ignition of oil-soaked materials at room temperature.

Because most fires caused by spontaneous ignition of unsaturated vegetable oils on porous materials (i.e. oil soaked rags) occur at room temperature (10-25 degrees Celsius), a more meaningful method of testing was required. Past methods of characterizing these oils included iodine value and test where the sample was externally heated (Mackey Equipment Test). These methods did not fully address the behavior of these materials at room temperature conditions.

A graduate engineer at the Wuppertal University, Department of Safety Technology, Dr. Peter Schildhauer, developed a new method of testing. Dr. Schildhauer built a very simple testing apparatus.

In real life, many different factors influence spontaneous ignition. Dr. Schildhauer used this new testing apparatus to test various combinations of oil-soaked materials, solvents, concentration of chemical dryers, ventilation rates, sample bodies, and temperatures of the surrounding atmospheres. He then expanded these results and developed a method that tests spontaneous ignition fires that start in plastic containers.

The iodine value test for unsaturated oils is a used mainly in nutritional science and does measure whether a material is prone to spontaneous ignition. However, tests for chemiluminescence (CL) measure reactivity of the oils. Dr. Schildhauer compared the results of his room temperature test versus CL reactivity test results and found that the results correlated. The benefit of CL testing is that it considered a standard test, and has standard testing apparatus and software applications available.

Now that we believe that CL testing can be used to determine the likelihood that a particular unsaturated oil product may spontaneously heat and ignite, it can be used in investigations where spontaneous ignition is a suspected cause.