Well, not to be a downer, but wikipedia has some comments on the hazards... Environmental effects
Tetrafluoromethane is a potent greenhouse gas<http://en.wikipedia.org/wiki/Greenhouse_gas> that contributes to the greenhouse effect<http://en.wikipedia.org/wiki/Greenhouse_effect>. It is very stable, has an atmospheric lifespan of 50,000 years, and a high greenhouse warming potential<http://en.wikipedia.org/wiki/Greenhouse_warming_potential> of 6500 (CO2 <http://en.wikipedia.org/wiki/Carbon_dioxide> has a factor of 1); however, the low amount in the atmosphere restricts the overall radiative forcing <http://en.wikipedia.org/wiki/Radiative_forcing> effect. Although structurally similar to chlorofluorocarbons<http://en.wikipedia.org/wiki/Chlorofluorocarbons> (CFCs), tetrafluoromethane does not deplete the ozone layer<http://en.wikipedia.org/wiki/Ozone_depletion>. This is because the depletion is caused by the chlorine atoms in CFCs, which dissociate when struck by UV radiation. Carbon-fluorine bonds are stronger and less likely to dissociate. According to Guinness World Records<http://en.wikipedia.org/wiki/Guinness_World_Records> Tetrafluoromethane is the most persistent greenhouse gas. [edit<http://en.wikipedia.org/w/index.php?title=Tetrafluoromethane&action=edit§ion=7> ]Health risks Depending on the concentration, inhalation of tetrafluoromethane can cause headaches, nausea, dizziness and damage to the cardiovascular system<http://en.wikipedia.org/wiki/Cardiovascular_system> (mainly the heart). Long-term exposure can cause severe heart damage. Due to its density, tetrafluoromethane can displace air, creating an asphyxiation <http://en.wikipedia.org/wiki/Asphyxiation> hazard in inadequately ventilated areas. On Mon, May 21, 2012 at 5:08 PM, Jim Pflugrath <jim.pflugr...@rigaku.com>wrote: > Here is a trick which I will attribute to Cambridge: > > Fill balloon with gas. Put end of balloon over 15 ml Falcon tube. Put > Falcon tube in LN2. No wasted gas. > > I would recommend CF4 or carbon tetrafluoride instead of propane though. > CF4 is cheap and non-dangerous. > > Jim > > > ------------------------------ > *From:* CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Prince, > D Bryan [dbryan.pri...@astrazeneca.com] > *Sent:* Monday, May 21, 2012 4:15 PM > *To:* CCP4BB@JISCMAIL.AC.UK > *Subject:* [ccp4bb] Propane still? > > Good afternoon fellow ccp4bb’rs, > > > > I was wondering if anyone knows if a still to condense gaseous propane to > liquid propane using dry ice is commercially available. I want to make sure > that it is not something I can purchase before I build one fit to purpose. > I appreciate any advice and knowledge you can share. > > > > Regards, > > Bryan Prince > > ------------------------------ > > *Confidentiality Notice: *This message is private and may contain > confidential and proprietary information. If you have received this message > in error, please notify us and remove it from your system and note that you > must not copy, distribute or take any action in reliance on it. Any > unauthorized use or disclosure of the contents of this message is not > permitted and may be unlawful. > > > > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program email: j-kell...@northwestern.edu *******************************************
