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
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