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

Abstract

A standard reference material (SRM 1048) has been developed for use with the cup furnace smoke toxicity method. This SRM is to be used to calibrate the apparatus and to enable the user to have confidence that the method is being conducted in a correct manner and that the equipment is functioning properly. The toxicological results from this SRM should not be used to compare with those of other materials (i.e., to determine if the combustion products of a test material are more or less toxic than those from this SRM). SRM 1048 is an acrylonitrile-butadiene-styrene (ABS) and is the same as SRM 1007B which is used for calibrating the flaming mode of the Smoke Density Chamber test method (ASTM E-662 and NFPA 258). For the purposes of calibrating the cup furnace smoke toxicity method, LC50 and N-Gas values plus their respective 95% confidence limits have been determined and certified for two combustion modes (flaming and nonflaming) and two observation periods (for the 30 min exposure only and for the 30 min exposure plus a 14 d post-exposure period). The certified LC50 values plus 95% confidence intervals (in g/m3) are 27 ± 3 (30 min, flaming); 25 ± 3 (30 min+ 14 d, flaming); 58 ± 15 (30 min, nonflaming); and 53 + 12 (30 min+ 14 d, nonflaming). The certified N-Gas values plus 95% confidence intervals are 1.4 ± 0.2 (30 min, flaming); 1.5 ± 0.2 (30 min+ 14 d, flaming); 1.2 ± 0.2 (30 min, nonflaming); and 1.4 ± 0.2 (30 min+ 14 d, nonflaming). It is recommended that this SRM be used with the N-Gas approach to calibrate the cup furnace smoke toxicity method rather than to determine the complete LC50 values. The N-Gas approach has the advantage of providing information on the gases responsible for the lethalities as well as the toxic potency of the smoke. In addition, the N-Gas approach reduces the number of experimental animals, the time necessary to complete the calibration, and the expense.

Effects of fire-fighting on a fully developed compartment fire: Temperatures and emissions

“…It can be seen that for CO this dilution level is of the order of 200 whilst for acrolein the dilution required is of the order of several hundred rising to about 3000 during fire-fighting operations. These dilution levels are for the individual species and a combined requirement needs to be worked out using a procedure like the N-Gas model [26,39,40]. Mechanical ventilation systems for corridors are typically designed to give 100 times dilution of the combustion products seeping out to the corridor through leakage paths.…”

The development of a standard reference material for calibration of the University of Pittsburgh smoke toxicity method for assessing the acute inhalation toxicity of combustion products

“…Therefore, it is necessary to assure that such testing devices are installed and employed properly both by those laboratories currently conducting these tests and by new laboratories that enter the field. To help assure the reproducibility of results between laboratories, NIST has developed two standard reference materials (SRMs), one which can be used to calibrate the University of Pittsburgh smoke toxicity method (SRM 1049) and another SRM (SRM 1048) which can be used to calibrate the cup furnace smoke toxicity method [ 15 ]. It is important to note that these SRMs were not selected to represent the toxic potency of the combustion products of an “average” material and are not designed to be used for the comparison of the relative toxic potency of the combustion products of test materials.…”