Hi, Some corrections 1) In Properties of Haz. Mat. slide, as per NFPA-30 liquids with < 37.8degC flash point only Flammable not < 61 degC. Liquids with flash point > 37.8 degC are Combustible. 2) In Temperature class slide: For Ethyl ether T4 shall be chosen not because of its Flash point as you say, its because of its Auto Ignition temperature.