The document discusses the changes in flammable aerosol testing regulations from HCS 1994 to HCS 2012, highlighting how certain products that were previously classified as non-flammable may now be deemed flammable. It outlines the testing methods, safety considerations, and specific criteria for categorizing flammable aerosols based on their chemical composition and combustion characteristics. The document also includes testing procedures and formulas for calculating heat of combustion and ignition distances.