Also to Brian and Everyone, Thanks to Lee for his information about HCHO, MEA, and ammonia emissions. We have done some source testing here at Merix to try and close the mass balance on our electroless baths. We used the T-0011 testing protocol, which uses a solvent (DNPH) to absorb the formaldehyde through a sampling train, similar to the stack testing methods. I am unsure whether this is similar to the methods used by Hadco. The T-0011 method had not been completely approved by EPA when we used it. However, it was the method of choice that the Oregon DEQ preferred. We got similar results to Hadco's. Basically, the formaldehyde conc. in the air stream was 2 ppm when the bath was on-line, and 1 ppm when the bath was off-line with air bubbling through it. This confirms Lee's comment that it is extremely difficult to strip HCHO out of an electroless bath. When we put that into our mass balance, we found that for every mole of HCHO that was consumed in a plate-out reaction (either onto the circuit board or onto the basket), approximately 1.2 moles of HCHO was consumed in the Cannizarro reaction: 2HCHO + H2O --> CH3OH + HCOOH. I think the magnitude of the Cannizarro reaction will depend alot on your actual electroless bath parameters (pH, temperature, concentrations, cleanliness of tank). Our tests around MEA emissions are a little dated, but they do agree with the information presented by Lee (i.e., not a whole lot). My only other comment would be that, for ammonia emissions, I believe that EPA gave some rather specific guidance for calculating ammonia emissions for the SARA 313 TRI reports for last year. I'm a little hazy on it, but I seem to remember about 10% of usage of aqueous ammonia usage? So it depends on whether you are trying to find a real answer or a regulatory answer (like so much of life). Call with any questions. John Sharp Merix Corporation 503-359-9300 (ext. 5-4351) 503-359-1040 FAX [log in to unmask]