Document KGoN9n2k938a1GNGGK6MJXj0o

November 20, 1962 Mr. Charles L. Cheever Argonn National Laboratory 9700 South Casa Avenu Argonn, Illinois Dear Mr. Cheaver: Therminol FR 1, 2, 3 heat transfer fluid* referred to in your letter of November 13, 1902 are chlorinated biphenyls. They are more refined forma of our Aroclor# 1242, 1246 and 1254. These compounds are biphenyls, chlorinated to 42, 48 and 54 respectively. There are enclosed three pieces of literature describing these liquid* which I think will answer your questions. Specifically, the potential fire hazard is not great since the advantage in using these fluids is that they are resistant. Health hazards are minimal except when the fluids are heated in open vessels or containers. \la feel that in any application where temperature exceed 150F, fluid* must be used in a closed system or adequate exhaust ventilation must be provided. I believe you will find the vapor pressure data In the enclosures serve as a basis of this recomaendation. We do not believe protective clothing la necessary to prevent skin contact during transfer of these fluids. They are not akin irritants in the usual sense of the word. They are excellent solvents and will dissolve the normal oils and fats of the akin possibly leading to drying and chapping if exposure is prolonged or repeated. Although the fluid may be absorbed through the skin with resulting systemic effects, this is not a serious hazard unless again, exposure is prolonged and repeated, we feel there la no significant absorption from acute single expo sures. Obviously, if workmen spill a Thermlriol fluid on the hands, it should be removed by washing. Similarly, grossly contaminated clothing should not be worn without laundering. In experiments where suitable animals were exposed to the decom position products of such fluids, toxic effect occurred in the anijnals only at concentrations which humans would not voluntarily endure because of irritation to the eyes and respiratory tract. The chief decomposition products are hydrochloric add, carbon COMPANY CONFIDENTIAL TRAN 019568 STLCOPCB4026575 Hr. Chari* L. Ch*v@r - Page 2 - Hovember 20, 1962 monoxide, eirbon dioxld, phenolic and aldehydes, in the stud! oonduotd for us by Kettering Laboratories, fluid wag allowed to drop oat inconel surfaoee hatd to 1050 and 1250P, Thar 1* essentially no decomposition below 600P. In our experience, exposure to these fluids in hatd transfer system has resulted only when the system has been Improperly Installed. Por example, son initial Installation have not carried Lhe vent line from the surge tank to the outdoors but have vented vapors of the fluid to workroom areas. In some initial installations, the piping that was used had threaded Joints whereas we recommend a system less subject to leaks. Such practices may allow chronic exposure to vapors which must be avoided. In the history of the use of these fluids, there have been instances when the fluid has been sprayed into open flames or - In the case where the fluids are used as hydraulio fluids - line ruptures have caused the fluid to be sprayed on molten metal. Fires have never occurred under these circumstance. Depending on the amount of fluid involved and the temperatures, the working environment becomes filled with clouds of smoke and vapors such that the area must be vacated. Workmen have always had the opportunity, however, to stay in the area long enough to shut down operations without suffering serious toxic effects. If I can be of any further assistance, please do not hesitate to let me know. Very truly yours. J+mf Enclosures Jack T. Garrett Industrial Hygienist Medical Department COMPANY CONFIDENTIAL TRAN 019569 STLCOPCB4026576