I revealed there was great variability in both the vapor phase and soluble organic fraction of particulate emissions, but that the particle size was consistently less than 1 m. The first step in assessing risk is identifying the chemical hazards associated with candle emissions. While unit risk values exist for many of the vapor phase emissions from candles, unit risk values for candle soot have not been developed. IARC has classified diesel exhaust as a probable human carcinogen 2A . Although lead was only detected in the emissions of 5 out of 91 candles, the implications of lead exposures from a previously uncharacterized source supports its inclusion in this risk assessment.
Extensive data exist on exposures to lead in both occupational and residential settings.
Tremendous resources have been expended to remove lead containing materials from homes and schools. Exposure Modelling Due to the lower air exchange rates in newer homes, the residence time of emissions were determined to continue for up to 10 hours after extinguishing a candle. Risk Characterisation Scented candles have become common-place in homes and in certain businesses such as boutiques, salons, and spas. However, the indoor environment where the most significant exposures are likely to take place, due to low ventilation rates and long duration of occupancy, are homes. Chapter 5 - Discussion Scented candle usage indoors may cause high levels of respirable soot, with risks to occupants for both acute and chronic health effects, including an increased risk of cancer.