The European Union’s Scientific Committee on Emerging and Newly identified Health Risks conducted studies on the risks and hazards associated with nanotechnologies, and found significant gaps in understanding the hazards associated with such products. The reports highlighted the fact that an understanding of the physiological response to nanoparticles and the dose response relationships for such responses is lacking. Our focus in this area has been the quantification of particle size distribution of nanoparticles, and the use of biochemical (enzyme assays) and biological (cell culture) models for quantification of nanoparticulate toxicity.
UBST Limited has been undertaking another project with the State Key Laboratory for Fire Science, at the University of Science and Technology of China, in Hefei, to investigate the release of nanoparticles during burning. These nanoparticles are naturally present in fire effluents, from soot particles down to very large molecules, such as fullerenes (C60, C70 etc.). Some of these particles have the capacity to penetrate deep into the lung, and even cross the blood-gas barrier. The project is investigating any adverse impacts on health.
Amongst the many and varied applications of nanotechnology, the dispersion of nanoscopic fillers to form polymer nano-composites with improved mechanical properties and fire behaviour illustrates the potential and diversity of nanoscience. Polymers decompose in different ways and fire retardants act to inhibit the decomposition or flaming combustion processes. Polymer nanocomposites form barriers between the fuel and air, reducing the rate of burning, but beyond that there is little consistency in their effects. The rheological properties of molten polymer nanocomposites are radically different from those of virgin polymers, and these profoundly affect the heat and fuel transfer through the material, often resulting in shorter times to ignition but lower peaks in the heat release rate. Most fire deaths result from inhalation of toxic gases; many who escape from fire die soon afterwards because of damage to their lungs; fire survivors often suffer injury from toxic smoke inhalation. While the majority of deaths in fires are caused by inhalation of carbon monoxide and hydrogen cyanide, the incapacitating effects of particulates and other irritants may prevent escape and thus be the reason for the deaths.
UBST Limited has been undertaking a project with the State Key Laboratory for Fire Science, at the University of Science and Technology of China, in Hefei, to develop new fire retardant materials. This project aims to understand the underlying fire retardant mechanisms, in order to develop a new generation of fire retardant additives. It is focussed on changes to physical properties; either through the incorporation of chemically active species (e.g. char promotion) or through incorporation of nanoparticles (to increase the thermal conductivity or reduce the fuel gas flow to the flame etc.). Techniques currently being investigated include the use of carbonisation catalysts and intumescence.
Anna’s recent work focused on better understanding the assessment of toxic and irritant life hazards in fires and the factors affecting fire gas toxicity. Detailed studies of the yields of fire gases and other combustion products have been undertaken in order to predict the effects of fire exposures to humans. This work has clarified the relative importance of incapacitation and lethality, and demonstrated that carbon monoxide is not the only significant toxicant in fire gas. Anna’s attendance and active participation at BSI Hazard to life from fire, and ISO Fire threat to people and environment meetings, where she has been designated as the UK’s principal expert on fire chemistry over the last four years, has given her the unique opportunity to become acquainted with the world’s leading fire toxicity experts from across the globe.
Richard Hull is the Professor of Chemistry and Fire Science at UCLan. His expertise is in the decomposition and flammability of plastic materials. This has led him to investigate the behaviour and suitability of fire retardants for a range of plastics, and the causes of fire effluent toxicity, which is the major cause of death and injury in fires. He is internationally-leading in the field of fire science, with over 100 publications on fire retardancy and fire toxicity.