Every piece of Ex-certified equipment has a maximum surface temperature rating. This episode explains the T1 through T6classification for gases, how dust temperature limits are calculated differently (using cloud and layer ignition temperatures), and why gas group and temperature class are independent parameters that both need to be satisfied. Covers common gases and their T-classes, the carbon disulfide paradox (IIC but T5), dust calculation examples, and practical factors like ambient temperature, self-heating, and solar radiation. More info: https://exknowledge.com