Lethality of Carbon Monoxide, Sulfur Dioxide and TNT

Air monitoring provides the following contaminant concentrations at the approximate center of a fire scene in which acres of automobile tires are burning:

Carbon monoxide at 1700 ppm; Carbon dioxide at 7000 ppm; and Sulfur dioxide at 600 ppm. Ignoring synergistic effects between these gases, which individual concentrations are considered life-threatening to the EH&S or FS professional responding to the scene? What combustion products are produced when materials made from polyacrylonitrile smolder and burn? What combination of properties is responsible for the selection of trinitrotoluene as a military explosive?