he he he... I don't believe the HFC stands for HydroFluroCarbons (sp) like the original item did.
Some of the older "green Gas" containers I have state that they are "CFC Free."
The chemical content of the standard "Super Power Green Gas" is...
CH2 FCF3 CH3 at a purity of 99.7%
Contains .005% water
.0001% acid
1.8% Silicon Oil
In terms of "What gas is out there" and "what should I use in my gun..."
"Green Gas" is a generic term used to describe any form of gas used in an airsoft gun, as well as a specific term to denote a particular strength of gas. Confused? Just wait, it gets worse.
There are several forms of "green gas" that either have been made in the past or are available now.
Listed in order of increasing power:
HFC134a.
HFC22. (commonly called 'Green Gas')
"Red" Gas. (Not available outside of Japan or possibly Hong Kong)
"Black" Gas. (as above)
Most JAPANESE manufactured guns (Tokyo Marui, KSC, Tanio Koba) are rated for 134 gas.
"Most" guns made in Tiawan/Hong Kong are rated for the generic "Green gas." Most KJW and some KWA pistols can use HFC22 with little or minimal ill effects. Full metal guns (or those with upgraded valve systems) can use 'green gas' without issue.
Red and Black (I'm not even 100% certain these gasses are still sold today...) are more powerful, and will destroy guns that are not upgraded to their fullest potential. Such upgrades include metal slide/frame, recoil springs, different valve systems, etc.
Strait propane can be used, but it has no lubricant in it, so it leads to wear on internal rubber parts. Some people are switching to propane because it's very inexpensive. I just buy green gas because I hate the idea of having to mess with silicone every time I want to shoot.
And "back in the day" there was FLON gas, which I believe (but don't quote me on that one) was a strait up refrigerant. Most of Marui's early gas guns such as their MP5 and Scorpion used FLON. Ask Alex, he remembers those days.
VT and Exo are correct about using 100% silicone lube on your guns. It works fine as a cleaner, and all purpose lube. Radio shack has a semi-liquid 100% Silicone gel that I use for both cleaning and lubing my gas guns (and for cleaning my AEGs as well). It's cheap and works fine.
Russ
"Time has little to do with infinity and jelly doughnuts."