Toxic Potency of Fire Smoke

Abstract

Accurate measurement of the toxic potency of smoke is a key to reducing human life loss in fires.This paper summarizes the approaches taken in measuring toxic potency and highlights four needed issues still to be researched. Direct comparison of only toxic potency values is not a valid means of determining the fire safety of materials and is not sufficient for evaluating fire hazard. The paper describes the N-Gas Model (a new method of assessing toxic potency) and two approaches (in which toxic potency is one of the factors) for assessing fire hazard: (a) HAZARD I, a comprehensive tool for calculating the outcome of a fire, and (b) a fire hazard index for comparing the contributions of alternative materials to the toxicity component of fire hazard.As noted nearly five centuries ago, fires produce smoke; and as learned this century, most of the fire deaths in this country result from people breathing that smoke (1).Over the years, the United States and Canada have had the worst fire loss records among the industrialized countries which keep such records (2). At present, the United States suffers 6,000 deaths and 30,000 reported injuries per year (3). The annual property damage exceeds $7 billion, and the total cost of fire is over $50 billion (4).Many factors affect fire hazard, or the threat to life safety in a fire. This chapter not subject to U.S.

A Standard Reference Material for calibration of the cup furnace smoke toxicity method for assessing the acute inhalation toxicity of combustion products

“…The current N-Gas Model [ 15 – 18 ] equation is based on the studies at NIST of the toxicological interactions of six gases, CO, CO 2 , HCN, reduced O 2 , HCl, and HBr, and is used to estimate the amount of material (either loaded or consumed) necessary to produce an LC 50 for a 30 min exposure or a 30 min exposure plus a 14 d post-exposure period. LC 50 values for other exposure times can also be used.…”

“…The N-Gas Model has been developed into an N-Gas Method for predicting the concentration of material which would produce an LC 50 [ 15 , 16 ]. This method reduces the time necessary to evaluate a material and the number of test animals needed for the toxic potency determination.…”

Health Hazards of Composites in Fire

“…There are essentially two experimental approaches used to assess smoke toxicity: the analytical chemical method and the animal exposure test [eg. [6][7][8][9]. The chemical approach involves using analytical techniques such as gas chromatography/mass spectrometry (GC/MS) and Fourier Transform Infrared Spectroscopy (FTIR) to identify all the compounds and their concentrations in the smoke.…”

Tratamiento ignífugo de maderas

“…El 25 % de las muertes provocadas por el fuego se debe a que las personas permanecen atrapadas en los edificios (15): la mayoría de las víctimas son menores de 15 o mayores de 65 años. No solamente en las construcciones civiles el fuego genera importantes problemas, ya que en barcos, estructuras costa afuera, plantas petroquímicas, etc.…”

“…La toxicidad de los productos y gases de combustión se define co mo el efecto pernicioso de éstos en un sistema biológico, pudiendo ma nifestarse a corto o largo término (15). La toxicidad indirecta de los ga ses de combustión representa la ausencia o la presencia en cantidades insuficientes de elementos esenciales para las funciones vitales mien tras que la toxicidad directa determina la presencia de ciertos elemen tos que en cantidades suficientes, impiden igualmente las funciones hu manas vitales (18).…”