- Author
-
Grand, A. F.
|
Switzer, W. G.
- Title
- Effect of Oxygen Concentration on the Evolution of Toxic Gases From Douglas Fir, Rigid Polyurethane Foam and PVC. Final Report.
- Coporate
- Southwest Research Inst., San Antonio, TX
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
-
SwRI Project 01-3764; Final Report
November 1991
91 p.
- Contract
- NIST-GRANT-60NANBOD1056
- Keywords
-
polyurethane foams
|
rigid foams
|
polyvinyl chloride
|
oxygen concentration
|
toxic gases
|
combustion
|
carbon monoxide
|
hydrogen cyanide
|
hydrogen chloride
- Abstract
- The effects of ambient oxygen concentration on the combustion of three polymeric materials were determined in order to help define the appropriate conditions under which the laboratory radiant combustion and exposure apparatus is suitable for combustion studies, especially those used in smoke toxicity evaluations. Douglas fir (DF), rigid polyurethane foam (RPU) and polyvinyl chloride (PVC) were examined under various oxygen concentration ranging from 21 percent down to 14 percent at a heat flux of 50 kW/m2. The evolution of the gases carbon monoxide (CO), hydrogen cyanide (HCN) and hydrogen chloride (HCl) were measured. The results of this study indicate that oxygen concentration may significantly influence the yields of CO under flaming and nonflaming combustion conditions in some materials. In particular, the transition from flaming to nonflaming combustion often caused a dramatic change in the yield of CO. The yields of HCN and HCl were less influenced by changing oxygen concentrations. As a result of these studies, it is recommended that care be taken in selection of specimen size and in the monitoring of oxygen concentration (depleated due to combustion), in studies intended to compare the toxicities of smokes from different materials. Furthermore, it is recommended that toxic gas yield data, rather than concentration data, be used in fire hazard analysis calculations.