METHOD 18 BULLETIN

     It has come to my attention that testers are using canisters
(passivated, stainless steel, etc.) as a sampling procedure for
Method 18 (40 CFR Part 60, Appendix A).  Please note that this is
NOT ALLOWED as a sampling option under Method 18.  Please also
note that testers who have used canisters in conducting Method 18
tests in the past have been forced to repeat the test correctly
at no cost to the source.  

     In other news, Method 18 was modified on April 22, 1994 (as
part of the HON rule) to include new QA/QC procedures as part of
the method.  The new procedures mainly affect bag and adsorbant
sampling.  Method 18 now requires recovery efficiency studies on
each target compound for each source.  The bags/adsorbant tubes
are spiked and analyzed; recovery must fall between 70 and 130
percent recovery, and all test results must be corrected with a
correction factor based on the recovery test.  

     I'll be happy to talk further about the issues mentioned
above.  Please call me (Rima Dishakjian) at (919) 541-0443. 
Thanks.