Holly, You may also consider adding the following to your list : The elimination of Chlorine gas . The elimination of Silver Halide imaging film ( as a result of Laser Imaging . Improved filtration of photoresist material during the stripping process . Mike Covel Raytheon Systems Company Tucson Az. ______________________________ Reply Separator _________________________________ Subject: [TN] switch from chromic-based etchants Author: "TechNet E-Mail Forum." <[log in to unmask]>, at CCGATE Date: 6/22/98 11:31 AM Dear Technetters: I am writing a journal article on the environmental improvements the industry has made over the past 20 years. My list includes: - reduced use of tin-lead as etch resist - increased use of HASL alternatives - increased use of direct metallization - elimination of chlorinated solvents - switch from chromic-based etchants If any of you have any insight into the <underline>technical</underline> reasons, the industry adopted these improvements, I would greatly appreciate your insight and help (I really need help on the chromic acid section). You can respond to me directly through my e-mail address ([log in to unmask]). Thank you in advance. Holly Evans Director of Environmental and Safety Programs IPC 1400 Eye St., N.W., Suite 540 Washington, D.C. 20005-2208 phone: 202-638-6219 fax: 202-638-0145 e-mail: [log in to unmask] ################################################################ 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 technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ 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 technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################