A MODEL FOR THE CALCULATION AND THE VERIFICATION OF CLOSED CUP FLASH POINTS FOR MULTICOMPONENT MIXTURES

Regulatory issues related to material safety have made the accurate me asurement and/or prediction of flash points essential. The flash point is one of the major physical properties used to determine the fire an d explosion hazards of a liquid. Flash points are used by virtually al l governmental entities worldwide to define ''flammable'' and ''combus tible'' materials for shipping and safety regulations. A model is desc ribed here for the calculation of closed cup flash points for multicom ponent, single liquid phase, mixtures. The model is based upon rigorou s vapor/liquid equilibrium calculations supplemented with information about the lower flammable limits (LFL's) and heats of combustion (Delt a H-c's) for the mixture's constituent components. The closed cup flas h points predicted with this model are typically within +/- 5 degrees C of the experimentally reported values. Such a model is useful as a m eans of verifying experimental data and as a tool for screening produc t formulations prior to experimental flash point determination. The mo del should considerably enhance the safety evaluation portion of the p roduct development cycle, thus leading to shortened product time-to-ma rket cycles. While flash points calculated with this model are in exce llent agreement With experiment, experimental determination is still e ncouraged for critical safety applications.