Prediction of CO evolution from small‐scale polymer fires

The concentrations of decomposition products of polyethylene (PE), polypropylene (PP), polystyrene (PS), poly(methyl methacrylate) (PMMA) and 19% and 26% vinyl acetate-ethylene copolymers (19% EVA and 26% EVA, respectively) have been studied at equivalence ratios o varying from 0.5 to 1.5 using a Purser furnace. The CO yield of the fire gases increased with increase in fuel/air ratio. For PE, PP, PMMA and 19% EVA and 26% EVA, the CO evolution was independent of the polymer and depended only on o. PS gave higher CO yields at low fuellair ratios, and lower CO yields at high fuellair ratios in comparison with the other polymers studied. The CO yield translates to a fractional effective dose, showing a threefold increase in the fire toxicity in going from fuel lean (o = 0.5) to fuel rich (o = 1.5) conditions.