Document v6Mx3qYXapKrNp3B2xLvJ03xb

BCC: J.R. Fallon - JFALL D.8. Roush - DROUS Monsanto Monsanto Company 3158 Das Plaines Avenue Des Plaines, Illinois 60018 Chicago (312) 774-7400 Des Plaines (312) 296-6688 October 13, 1970 NORTHSTAR DAIRY 350 Endicott Bldg. St. Paul, Minnesota ATTN: Mr. Leo Graebner ' SUBJECT: New Plant Zumbrota, Minnesota Dear Mr. Graebner: With reference to our telephone conversation on Thursday, I would like to confirm our position regarding the use of Therminol 66 instead of Therminol FR-1 for the subject plant. In February of this year we learned that polychlorinated biphenyls (PCB) had been discovered in marine, aquatic and wildlife environments. Therminol FR-1 is a chlorinated biphenyl. We also learned that cer tain animals had the ability to concentrate it in their bodies. When this occurs and such animals may be used for food, the FDA enters the picture and establishes guidelines regarding concentration of the par ticular chemical in food products. In September the FDA issued a guideline regarding maximum concentra tion of PCB in food. The upper limit in milk is C.2 ppm and in other food products it is 5.0 ppm. Even before this FDA guideline we had advised existing users of Ther minol FR-1 in the food industry to consider replacing with Therminol 66 as we wished to eliminate any possibilities of food contamination. Most of our food industry users have already converted and the major ity of the remainder are scheduling conversions at a more convenient time. Typical, users of Therminol 06 in food process applications are: Company Food Product General Mills Minneapolis, Minn. Snack Food Frying Cargill, Inc. Des Moines, Iowa Edible Oil Deodorizer Corn Products (CPC Int'l.) Argo, Illinois Starch Process . qSVM 343590 STLCOPCB4096629 -2- Company Food Product Glidden Durkee Joliet, Illinois Edible Oil Deodorizer (New pit. - 2 months from startup) Therminol 66 is much more widely used in the chemical process industry and the major reason is that it is capable of operating at higher " temperatures than FR-1. We generally consider Therminol 66 for tem peratures up to 650F, whereas we limit FR-1 to 600F. In addition to it's higher temperature capabilities, Therminol 66 is also advantageous from the standpoint of better heat transfer (higher specific heat) and lower pumping costs. And most importantly, it does not exhibit the ability to concentrate either in the animal life chain or the envir onment. A copy of the toxicity data on Therminol 66 is also enclosed. The only disadvantage of Therminol 66 is it's inability to be clas sified as fire resistant; yet with all of our installations in chemical process plants we have not to date, recorded a single fire. Since a statement like "fire resistant" is strictly relative the classifica tion by UL should shed some light on the fire resistance of various fluids. . Product UL Classification Therminol FR-1 2-3 Paraffin Oil 10 - 20 Kerosene 30 - 4o Alcohol, 60 - 70 Gasoline 90 - 100 Ether 100 In this classification Therminol 66 would fall in the range of 10-15. Generally the only extra precaution in a Therminol 66 system might be to consider a sprinkler system for the use area and a manual steam snuffer for the combustion chamber of the heater. I hope that this letter answers the major questions regarding the use of Therminol 66 for the subject plant. The idea of using a liquid phase system to produce steam and hot water is not only very flexible but it can also result In a tremendous labor savings over the con- OSNN 3435^ i `~ * t.. .>..... n STLCOPCB4096630 -3- ventional steam system. We would very much value you as a customer yet we feel that it is in the best interests of both parties to use Therminol 66. . Very truly yours. JJR/s aa ENC's CC: Mid-American Dairyman P.0. Box 1837 Springfield, Mo. 65805 ATTN: Mr. D.K. Harmon Mechanical Design, Inc. P.0. Box 5069 Madison, Wisconsin 53705 ATTN: Bert Johnson Heat Transfer Specialist THERMINOL DSVJ 343502 STLCOPCB4096631