Use of an Approximate Lethal Exposure Method for Examining the Acute Inhalation Toxicity of Combustion Products

Abstract

An approximate lethal exposure (ALE) method for acute inhalation toxicity testing of thermal decomposition products was developed and evaluated. In comparison to "traditional" LC₅₀ calculation methods, the ALE method re quired 70% fewer animals and 50% fewer test runs. The ALE procedure relied on analysis of combustion gases and their limited animal testing (F-344 rats). The procedure was used to evaluate eight materials under flaming (5.0 W/cm²) and nonflaming (2.5 W/cm²) conditions. The complete 30-minute L(Ct)_50's were also calculated for five of those eight materials and compared to the ALE's. The ALE's were within eleven percent of the calculated L(Ct)_50's at 5.0 W/cm² and ranged within thirteen to fifty-five percent of the L(Ct)_50's at 2.5 W/cm². A microcomputer data acquisition and control system to improve data collection and Ct product calculation is also described for the radiant furnace test method for improved data collection and concentration-time product calculation.

Get full access to this article

View all access options for this article.

References

Alarie, Y.C. and Anderson, R.C. , "Toxicologic and Acute Lethal Hazard Evaluation of Thermal Decomposition Products of Synthetic and Natural Polymers," Toxicol. Appl. Pharm., 51, pp. 341-362 (1979).

Alarie, Y.C. and Anderson, R.C. , "Toxicologic Classifications of Thermal Decomposition Products of Synthetic and Natural Polymers," Toxicol. Appl. Pharm., 57, pp. 181-188 (1981).

Alexeeff, G.V. and Packham, S.C. , "Evaluation of Smoke Toxicity Using Concentration-Time Products," J Fire Sci., 2, pp. 362-379 (1984a).

Alexeeff, G.V. and Packham, S.C. , "Use of a Radiant Furnace Fire Model to Evaluate Acute Toxicity of Smoke," J. Fire Sci. , 2, pp. 306-320 (1984b).

Anderson, R.C. and Alarie, Y.C. , "Screening Procedures to Recognize 'Supertoxic' Decomposition Products from Polymeric Materials Under Stress," J. Combus. Toxicol., 5, pp. 54-63 (1978).

Ballantyne, B. , "Relative Toxicity of Carbon Monoxide and Hydrogen Cyanide in Combined Atmospheres," Toxicologist , 4, p. 69 (1984).

Bruce, R.D. , "An Up-and-Down Procedure for Acute Toxicity Testing," Fundam. Appl. Toxicol., 5, pp. 151-157 (1985).

Deichmann, W.B. and LeBlanc, T.J. , "Determination of the Approximate Lethal Dose with About Six Animals," J. Ind. Hyg. Toxicol. , 25, pp. 415-417 (1943).

Finney, D.J. , Probit Analysis, Third Edition, Cambridge University Press, Cambridge, England (1971).

10.

Gad, S.D. and Smith, A.C. , "Influence of Heating Rates on the Toxicity of Evolved Combustion Products: Results and a System for Research," J. Fire Sci. , 1, pp. 465-479 (1983).

11.

Hartzell, G.E. , Packham, S.C. and Switzer, W.G. , "Toxic Products from Fires," Am. Ind. Hyg. Assoc. J., 44, pp. 248-255 (1983).

12.

Hilado, C.J. and Cummings, H.J. , "A Review of Available LC50 Data," Comb. Toxicol., 4, pp. 415-424 (1977).

13.

Karter, M.H. and Gancarski, J.L. , "Fire Losses in the United States During 1983," Fire J., 78(5), pp. 48-67 (1984).

14.

Lee, B.T. , "Standard Room Fire Test Development at the National Bureau of Standards," in Application of Fire Science to Fire Engineering (D. Jones Ed.), ASTM STP 882. American Society for Testing and Materials, Philadelphia, PA (in press).

15.

Levin, B.C. , Fowell, A.J. , Birky, M.M. , Paabo, M. , Stale, A. and Malek, D. , "Further Development of a Test Method for the Assessment of the Acute Inhalation Toxicity of Combustion Products," NBSIR82-2532, National Bureau of Standards (U.S.) Gaithersburg, Maryland (1982).

16.

Lieberman, H.R. , "Estimating LC50 Using the Probit Technique: A Computer Program," Drug Chem. Toxicol. , 4, pp. 111-116(1983).

17.

MacFarland, H.N. , "Respiratory Toxicology," in Essays in Toxicology (F. R. Blood, Ed), Vol. 7, pp. 121-153, Academic Press, New York (1976).

18.

Molinegro, L. , "The Curve Doses vs. Survival Time in the Evaluation of Acute Toxicity," J. Pharm. Pharmacol., 31, pp. 343-344 (1979).

19.

Muller, H. and Kley, H.P. , "Retrospective Study on the Reliability of an "Approximate LD50" Determined with a Small Number of Animals," Arch. Toxicol., 51, pp. 189-196 (1982).

20.

Paabo, M. , Birky, M.M. and Womble, S.E. , "Analysis of Hydrogen Cyanide in Fire Environments," J. Combust. Toxicol., 6, pp. 99-108 (1979).

21.

Packham, S.C. and Crawford, M.B. , "An Evaluation of Smoke Toxicity and Toxic Hazard of Electrical Nonmetallic Tubing Combustion Products," J. Fire Sci., 2, pp. 37-59 (1984).

22.

Schutz, E. and Fuchs, H. , "A New Approach to Minimizing the Number of Animals Used in Acute Toxicity Testing and Optimizing the Information of Test Results, Arch. Toxicol., 51, pp. 197-220 (1982).

23.

United States Environmental Protection Agency (USEPA) , Acute Exposure Inhalation Toxicity Guidelines, HG-Acute-Inhal, Office of Toxic Substances, Office of Pesticides and Toxic Substances, Washington, D.C. 20460 (1984).

24.

Wooley, W.D. , "Toxic Products from Plastic Materials in Fires," Plastics Polymers, 41, pp. 280-286 (1973).