Isocyanates, aminoisocyanates and amines from fires—a screening of common materials found in buildings

Abstract

SUMMARYIsocyanates, aminoisocyanates and amines were quantified from the combustion of 24 different materials or products typically found in buildings. Small-scale combustion experiments were conducted in the cone calorimeter, where generally well-ventilated combustion conditions are attained. Measurements were further made in two different full-scale experiments.Isocyanates and amino-compounds were sampled using an impinger-filter sampling system with a reagent solution of di-n-butylamine in toluene. Filter and impinger solution were analysed separately using LC-MS technique. Further the particulate distribution in the smoke gases was determined by impactor technique, and selected gaseous compounds quantified by FTIR.It was found in the small-scale that isocyanates were produced from the majority of the materials tested. The highest concentration was found for glass wool insulation, and further high concentrations were found for PUR products, particleboard, nitrile rubber and melamine. Lower concentrations were found for wood and cable-products. Amino-isocyanates and amines were generally found from PUR products only.The distribution of isocyanates between the particulate-and fluid phases varied for the different materials and a tendency to enrichment of particles was seen for some of the materials. Further, when comparing the potential health hazard between isocyanates and other major fire gases (based on NIOSH IDLH-values) it was found that isocyanates in several cases represented the greatest hazard.

Ferrocenoyl piperazide as derivatizing agent for the analysis of isocyanates and related compounds using liquid chromatography/electrochemistry/mass spectrometry (LC/EC/MS)

“…PIC was found in very high concentrations as well. As was expected from literature data [43], isocyanic acid (ICA), MIC, EIC, and propyl isocyanate are all detected as degradation side-products at low concentrations in the undiluted impinger solution. However, the selected sampling arrangement does not allow a quantitative evaluation of these data.…”

“…It is known from literature that, besides the isocyanate which was used for synthesizing the polymer, smaller isocyanates may be observed during this procedure [43]. This simulates a welding process at a metal pipe, which is insulated with polyurethane material.…”

Toxicity Assessment Of Products Of Combustion Of Flexible Polyurethane Foam

“…Open flaming hazards have been studied both in small scale and large scale, with general indications that the results are not seriously effected by scale. However, the work of Blomquist et al [2,3] casts some doubt on the completeness of earlier work. Only a single investigation has explored toxic hazards in under ventilated compartment fires using animal exposures.…”

“…Blomquist et al [2,3] studied the production of isocyanates and amino compounds in flaming fires using the cone calorimeter and an ISO 9705 room test exclosure. They judged the relative toxic hazard contributions of HCN, CO, and isocyanates by expressing the average exhaust gas concentrations to "immediately dangerous to life or health" (IDLH) values reported by NIOSH, i.e., 50, 1200 and 3 ppm (value for methyl isocyanate was used to represent all isocyanates), respectively.…”

“…The general view in the fire science literature is that toxic hazards from flexible polyurethane foam are primarily from carbon monoxide with some secondary contribution from hydrogen cyanide [1]. However, there have been recent observations by Blomquist et al of isocyanates generated by fires involving nitrogen containing fuels [2,3]. Flaming combustion experiments in the cone calorimeter and burning of a couch in a ISO 9705 room indicate that isocyanates may contribute to the toxic hazard.…”