I worked for 10 years as an environmental chemist. Dissolved iron can be induced to photo-oxidize fairly easily; the intense UV from your sterilizer would definitely carry enough energy to initiate this process. Shawn Keslar WVU Network Services PO Box 6860 Morgantown, WV 26506-6860 (304) 293 5133 --- StripMime Report -- processed MIME parts --- multipart/alternative text/html ---