The mixture you describe in your communication (1.6% CO, 11% CO2, 600ppm Propane, 8 scf) is known as a BAR 84 in a Scotty III Transportable cylinder. This mix can be ordered through our Plumsteadville, Pennsylvania manufacturing facility. Please contact Customer Service at 1-800-331-4953 for leadtime and pricing information. Regards, Jim Kraus Technical Service Engineer Scott Specialty Gases, Inc.