The parameter which is determined is the time after which a moist potassium iodide-starch paper turns violet or blue when exposed to gases evolved by one gram of the explosive at 82,2 °C 180 °F). In commercial nitroglycerin explosives e.g. this coloration should only develop after 10 minutes or more. In a more sensitive variant of the method, zinc iodide-starch paper is employed. Today the Abel test is still used in quality control of commercial nitrocellulose, nitroglycerin and nitroglycol, but it is practically speaking no longer employed in stability testing of propellants. The test was proposed by Abel in 1875. Meyer, 1977. This test can also be used to determine the degree of deterioration of an explosive that may have occurred during the period of storage. McAdam & Westwater, 1958.