INHALATION TOXICOLOGY: V. EVALUATION OF RELATIVE TOXICITY TO RATS OF THERMAL DECOMPOSITION PRODUCTS FROM TWO AIRCRAFT SEAT FIRE-BLOCKING MATERIALS

Two fire-blocking layer materials, designed to delay the thermal decomposition of polyurethane foam seat cushions during an aircraft cabin fire, were evaluated for the relative toxicity of their gaseous combustion products. Each material was thermally decomposed under five distinct thermal environments: two contact temperatures in a horizontal hot tube furnace and three flux levels in a radiant heat furnace. The measured toxicological endpoint was time-to-incapacitation (ti) in a laboratory rat; this endpoint is believed to be the most relevant one for assessing smoke hazard in a fire environment. In three of the five test environments, Norfab, an aluminized synthetic fabric, produced shorter ti's (and thus was more toxic) than Vonar, a neoprene foam. However, at the lowest flux level in the radiant furnace system, the Norfab test specimen lost only 13% of the sample weight and did not incapacitate any of the test animals during the exposure period. At 750 deg C (flaming) in the combustion tube assembly, Norfab produced longer and more variable ti's than did Vonar. Hydrogen cyanide (HCN) was detected in the combustion products from Norfab under all test conditions except the lowest radiant flux level. No HCN was detected in the combustion products for any of the Vonar tests. Since Norfab routinely produced lower concentrations of carbon monoxide than did Vonar under all test conditions, the greater apparent toxicity (shorter ti's) of Norfab would appear to be caused by the cyanide production.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 13 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00960818
  • Record Type: Publication
  • Report/Paper Numbers: DOT/FAA/AM-86/1
  • Files: TRIS, USDOT
  • Created Date: Jul 29 2003 12:00AM