In a message dated 09/02/1999 10:26:27 AM Central Daylight Time, [log in to unmask] writes: << TechNetters - some of our assembly techs use MEK to remove flux. I know MEK is potent and probably shouldn't be used for flux removal. What I need is some justification WHY we shouldn't use MEK. We are soldering 22 gauge stranded wire to connector lugs and microswitch turret terminals. This assembly is part of a fuel control for commercial fanjet engines. We use Sb5WS (Tin 94%, Lead 0.2%, Antimony 4-6%) solder and Kester 197 Flux, which is type RMA. Any help is appreciated. Regards, Dave Hipp Woodward Aircraft Engine Systems Electrical Production Engineering (815) 639-6732 FAX (815) 636-6040 >> Hi Dave! MEK? Hoo-boy, that's some STRONG solvent just to clean the type of residues that alcohol would work just fine for. Here's some ammo that you can use, tell your people as long as they comply with the information below, they can use MEK. To do anything otherwise, would set them up for a lawsuit should something ever happen. I would think they would heed this advice... -Steve Gregory- How can I work with methyl ethyl ketone safely? This material is a FLAMMABLE AND VERY TOXIC LIQUID (POSSIBLE REPRODUCTIVE HAZARD). Before handling, it is extremely important that engineering controls are operating and that protective equipment requirements are being followed. People working with this chemical should be properly trained regarding its hazards and its safe use. Eliminate all ignition sources (e.g. sparks, open flames, hot surfaces). Keep away from heat. Post NO SMOKING signs. It is very important to keep areas where this material is used clear of other materials which can burn. Electrically ground all drums, transfer vessels, hoses and piping. Ground clips must contact bare metal. When dispensing in other than a closed system, ensure dispensing container is bonded to receiving transfer equipment and container. Never perform any welding, cutting, soldering, drilling or other hot work on an empty vessel. To reduce the fire/explosion hazard, consider the use of an inert gas in the container or storage vessel. Use non-sparking ventilation systems, approved explosion-proof equipment and intrinsically safe electrical systems in areas of use. Keep aisles and exits free of obstruction. For large scale operations, consider the installation of leak and fire detection equipment along with a suitable, automatic fire suppression system. Avoid generating vapours or mists. Prevent the release of vapours and mists into the workplace air. Wear appropriate personal protective equipment, if necessary, to avoid contact with this chemical and any contaminated equipment. Use in smallest possible amounts in a well-ventilated area separate from the storage area. Do not use with incompatible materials such as oxidizers and acids. Vigorous reactions followed by fire or explosion could result. Test for peroxides before distilling. To avoid splashing, carefully dispense into sturdy containers made of compatible materials. Never transfer liquids by pressurizing the original shipping containers with air or inert gas. Do not dispense in storage area unless dispensing area is segregated by fire-resistant construction. Only use portable containers and dispensing equipment (faucet, pump, drip can) approved for flammable liquids. Never return contaminated material to its original container. Label containers. Keep containers closed when not in use. Avoid damaging containers. Empty containers may contain hazardous residues. Follow handling precautions on Material Safety Data Sheet. Have suitable emergency equipment for fires, spills and leaks readily available. Practice good housekeeping. Maintain handling equipment. Comply with applicable regulations. ############################################################## TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################