Eric Guillaume, Efectis France, presented developments in safety standards for smoke toxicity. Smoke is the main killer in fires, and deaths due to smoke have not fallen as rapidly in developed countries as those due to burns.
Assessing smoke toxicity is however very complex. Some toxicants are considered for their acute effect, i.e. effects on occupants during fires and others are considered for their chronic effects, i.e. for firefighters. Penetration can be via inhalation or through the skin, and the exposure scenario is a key point (duration, intensity). Gases with acute toxicity are, most importantly, carbon monoxide; in some circumstances hydrogen cyanide, carbon dioxide; and to a lesser extent hydrogen chloride, bromide and fluoride, sulphur dioxide, nitric oxides, aldehydes, ammonia and others. Gases with chronic effects are mainly aromatic hydrocarbons (e.g. benzene, phenol, toluene, styrene), PAHs (polycyclic aromatic hydrocarbons) and organo-halogens (dioxins / furans). Scenarios and models for tenability and lethality assessment differ. Consequently, there are many different standards for measuring smoke toxicity in different applications (cables, railways, marine …), as well as standards for smoke opacity and smoke acidity. Assessment should be made at the end-use scale, because smoke toxicity is a scenario-related parameter driven by fuel as well as ventilation conditions. Fire safety engineering is the proper tool for such assessment.