Document NpOzEv5g5egwLBMYYbYy978E

Conoco Chemicals Company Conoco Inc. P. O. Box 91, Nsw Highway 26 Aberdeen, Muisslppi 39730 (601) 369-8111 June 24, 1983 Mr. Jerry B. Banks, F.E. Mississippi Department of Natural Resources Bureau Of Pollution Control P. 0. Box 10385 Jackson, MS 39209 Dear Mr. Banks: In September 1982 EPA revised Method 107, which is used to determine the vinyl chloride content of polyvinyl chloride resin (PVC) following the steam stripping step of the PVC process. The revised method specifies that certain chromatographic columns and operating parameters must be used, however, it is also stated that alternate columns and operating parameters may be used, subject to the approval of the Administrator. It is our understanding that approval of the alternate columns and operating parameters is automatic upon notification of the Mississippi Department of Natural Resources, The purpose of this letter is to Inform you that Conoco has selected alternate chromatographic columns and operating parameters, as indicated below. Method 107 Conoco Aberdeen Plant Parameter Recommendation Apparatus/Procedure Reference Columns Stainless steel lm X 3.2nm and 2m x 3.2mm 50/80 mesh Porapak Q Stainless steel %n X 3.2mm and lm X 3.2mm 100/120 Porapak Q 6.3.2 Oven Temperature 140 C 100UC 8.3.1.2(a) Conoco has developed confirming data showing that resolution interferences are not encountered under the alternate operating conditions. The data is available for review upon request. If you have any questions or comments, please contact either Dave Mahler or Dave Cox at (601) 369-8111. DTH 000105852 John Friend Plant Manager c: RAF DLM, DSC, JCL f