A colorless gas (CO), lighter than air and highly toxic by inhalation, with an ignition temperature of 11280F and an explosive range of 12. 5 to 74 percent
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}