Volatility and mists-electrical area classification´s important variables

North American area classification standards have neither addressed nor provided guidance on the impact that volatility and mists have on the extent of classified areas. While the more conventional criteria of quantity of release and the type of flammable material (e.g., hydrocarbon) being released are important, this paper shows that volatility and misting are also important in defining the extent of classified area. The method of classifying areas introduced in Appendix D of API RP 500 and RP 506 provides a method of taking volatility into consideration. The paper discusses API RP 500 and RP 506