Combustion products from ventilation controlled fires: toxicity assessment and modelling

Toxic smoke from fires is regularly identified as the leading cause of death in fire casualties. In most countries statistics suggest more than 70% of fire deaths are caused by either toxic smoke inhalation, or heat burns and toxic smoke inhalation. In most cases, fire victims are impaired from escape due to smoke irritation and poor visibility. The fire community is now recognising the need for further research into the sub-lethal toxicity, as in most cases fire victims are impaired by these sub-lethal effects from making a safe escape. However, despite the recognition of the importance of the fire toxicity problem, limited work is done on quantifying the different fire smoke products. The available information is incomplete, and in many cases misleading. This work, attempts to address the fire toxicity problem in depth. By using state of the art experimental techniques, a thorough investigation into toxic components of fire effluent is conducted. Using a specially designed reduced scale enclosure, and an FTIR sampling system, a series of experiments were conducted examining the toxic products of low ventilation compartment fires. As a first objective, a review was conducted into the current practice of fire toxicity assessment; it was found out, that in most cases, the previously developed models, overlook the irritancy and sub-lethal quantification by adopting the lethal end-point for assessment. A review on the work exposure limits, and its relation to fire was provided. In addition, this research included experimentally examining different types of fire fuels, relevant to residential and industrial fires. The fuels studied included wood cribs, cotton towels, acrylic curtains, and hydrocarbon pool fires. The fires were burnt at ventilation rates corresponding to 5, 11, 21, 37 ACH, which simulated conditions of a limited ventilation enclosures in modern buildings. Quantified yields of irritant species, such as Acrolein, Formaldehyde, Benzene, Acetic Acid, and Acetaldehyde, are reported on a scale never accomplished before. In addition, detailed assessment of the measured species in terms of lethality and irritancy was reported. The amount of information gained from the experimental work, expanded our current understanding on toxic fire effluent, and was published in a series of publications. Finally, the gained knowledge from the experimental work was then used in an attempt to propose a new methodology for toxic fire prediction in fire models.