DCHAS-L Archives · Post dated April 26, 2007
From: Gordon Miller <miller22**At_Symbol_Here**LLNL.GOV>
Subject: Re: Speciality Calibration Gas source inquiry
Date: Apr 26, 2007 18:40 UTC
Reply-To: Gordon Miller <miller22**At_Symbol_Here**LLNL.GOV>
In-Reply-To:
ERPG-1, -2, and -3 values for it are: Hexafluoropropylene (116-15-4) 10 ppm 50 ppm 500 ppm. Old-fashioned refrigerants look very good when human toxicity is factored in... At 9:45 AM -0700 4/26/07, Russell Vernon wrote: >Dear Fellow Chemists, > > > >In California we are being required to test some of our fume hoods with >a tracer gas. We are also being encouraged to reduce our greenhouse gas >emissions. The standard method, ASHRAE 110-1995, calls our sulfur >hexafluoride as the tracer gas of choice. It takes about 0.5 to 1 kg of >tracer gas for each test. SF6 has 23,900 times the global warming >potential of CO2 largely dues to its stability and very long residence >times in the atmosphere. ASHRAE 110-1995 allows for alternative tracer >gases to be used but requires that they are similar in weight, stability >and detection limits to SF6. > > > >The best alternative I've found so far is hexafluoropropene [116-15-4]. >The current director of our Air Pollution Research Center >(www.aprc.ucr.edu <http://www.aprc.ucr.edu/> ) assures me that >hexafluoropropene will hang around in the atmosphere only 4-5 days so >will not have the dramatic negative environmental impact of SF6 (also it >will not deplete the stratospheric ozone). > > > >I have found a local fume hood certifier that is set up to conduct the >ASHRAE 100-1995 test who is willing to try a new gas, but his detector >is calibrated to SF6. > > > >We contacted the manufacturer of his Q200 leak detector and they need a >certified calibration gas source. Normally they use a 1% mix of gas in >nitrogen, and fill a 0.6 liter bottle with it to a pressure of between 4 >and 10 bar. The set the leak rate of the gas at either 1 x 10-7 or 1 x >10-6 cc/sec, which corresponds to 0.1 and 0.2 ppm respectively. > > > >Can you recommend a lab, supplier or manufacturer that would be willing >to create a certified mixture of 1% hexafluoropropene in nitrogen? > > > >(The manufacturer of the Q200 is in the UK so a European source may be >the best.) > > > >Sincerely, > >-Russ > >Russell Vernon, Ph.D. >UC System-wide Field Safety Working Group Chair >http://ehs55.ehs.uci.edu/fieldsafe/index.jsp ><http://ehs55.ehs.uci.edu/fieldsafe/index.jsp> >Laboratory / Research Safety Specialist & Integrated Waste Manager >Environmental Health & Safety >University of California, Riverside >900 University Ave. >Riverside, CA 92521 > >russell.vernon**At_Symbol_Here**ucr.edu >www.ehs.ucr.edu > >Direct: (951) 827-5119 >Admin: (951) 827-5528 >Fax: (951) 827-5122 > >