Chris, Read your questions on TechNet . Here is our experience at Lockheed Martin OR&SS in regards to No Clean: Question #1 : No Clean fluxes are allowable under the commercial specifications J-STD-001, Requirements for Soldered Electrical and Electronic Assemblies. No Clean flux material is called out under J-STD-004. Not familiar with Def Stan 34-4. J-STDs are Joint Industry Standards developed and endorsed by EIA and IPC. Question #2 : I participated in an Advance Research Projects Agency (ARPA) that studied the use of No CLean Process in Assembly of Military SMT Cards. This was completed 31Dec1995 under Contract # MDA972-93-C-0034 . We built many circuit cards that were a mix of PWB material, conductor finish and conformal coatings with a No Clean solder paste with no deleterious affects. There were also studies done by Sandia National Labs and Georgis Tech around the same time. An executive summary is available. Question #3 : Not familiar with rosin flux fume restrictions. I can be contacted by phone at (315) 456-1820 from 7:00 -3:30 PM EDST. ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################