AbstractThis paper examines the effect of different thermal regimes on the production of smoke from a variety of injection‐moulded polypropylene samples. The tests were performed in a Stanton Redcroft BS 6401 smoke chamber. The results indicate that, of the thermal regimes examined, the radiant heat source alone produced the smoke with the greatest optical density, particularly after long exposure times, while the addition of an inorganic salt to the polypropylene produced a reduction in optical density. The different thermal regimes produced different effects depending on the additives used in the preparation of the polypropylene sample