As with all reagents used in the lab it is best to understand the health hazards. Thanks for note.
Jim ________________________________ From: Jacob Keller [j-kell...@fsm.northwestern.edu] Sent: Monday, May 21, 2012 5:22 PM To: Jim Pflugrath Cc: CCP4BB@jiscmail.ac.uk Subject: Re: [ccp4bb] Propane still? 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<mailto: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<mailto:CCP4BB@JISCMAIL.AC.UK>] on behalf of Prince, D Bryan [dbryan.pri...@astrazeneca.com<mailto:dbryan.pri...@astrazeneca.com>] Sent: Monday, May 21, 2012 4:15 PM To: CCP4BB@JISCMAIL.AC.UK<mailto: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<mailto:j-kell...@northwestern.edu> *******************************************
