What about this response from a "chembeliver".
A real stretch,dont you think! =D>
"Chemtrails consist of dihydromonoxide. This chemical is called the "Silent Killer" and you can learn more at:
www.dihydomonoxide.org
A lot of people believe there is a separate tank and spraying system for chemtrails. This is not the case. Chemicals in the fuel are combined with the air in the combustion process to create dihyromonoxide which is sent out the exhaust. The flight and ground crews never know they are delivering chemical death. This significantly reduces the number of people in on the conspiracy.
Soon after leaving the engine the dihyodromonoxide turns from gaseous to its solid form which is naturally white. Barium clouds would be aquamarine in color."