Document 9JVpz4BjmKpOEdRZ07gRqJpYD

bcc: V/, R, Corey J. F, Stapleton H. S. Bergen July 14, 1972 Kr. John Weesel Office of Associate Co&aniEcioner for Compliance Food and Drug Administration CC-10 50OO Pishera Lane Rockville, Maryland 203^2 Dear John: Attached 1b a copy of Monsanto's comments relating to the proposed regulations for PCBs in food, animal feed and food packaging materiais. You will note on page 5 a reference to Monsanto'a experience with residual PCBs in converted heat transfer systems. I ora corresponding with several Monsanto locations to gather oddltional informa tion. As soon as the data is compiled and sumirariccd v.e would appreciate an opportunity to diecusa it with you and any other FDA personnel concerned. Warren or I will be contacting you eo soon as the information is available. Regards. Sincerely, M Attachment cc: iv, v * * .u. JL X. J V/. B. Pcjageorge Manager Bnv1rormcnto1 Protec tion -hingtor, D.C. OSW 019016 CL 4~ STLCOPCB4005560 July 14, 1972 Hearing Clerk Department of Health, Education and Welfare Room 6-88 56OO Fishers Lane Rockville, Maryland 28052 Re: Department of Health, Education and Welfare Food and Drug Administration 21 CFR Parts, 3* 121J 122* 128 Polychlorinated Biphenyls, Notice of Proposed Rule Making Federal Register, Vol. 37, No. 54, pp. 5705-5707 Saturday, March 18, 1972 Oentlemen: We have reviewed the Food and Drug Administration's pro posed regulations relating to PCBs in food, animal feed, food and feed processing plants and packaging materials. We agree with the Administration's intent to control the presence of PCBs in the nation's food supply and commit ourselves to continuing our activities directed toward this end. We endorse the recognition of the problem of unavoidable PCB residues in food and animal feeds. We support all appropriate action taken to prevent further introduction of additional PCBs into the environment. We equally support realistic action designed to minimize the unavoidable residues occurring from PCBs already pre sent in the environment. With respect to the rule making we have the following comments to offer: 1. The temporary tolerances for PCBs in milk and poultry should be maintained as originally established* 5.0 parts per million (fat bOEis) for milk and 5.0 parts per million edible portions for poultry. DSInl 019017 STLCOPCB4005561 Department of Health, Education and Welfare July 14, 1972 " Page 2 2. Residual PCBs are present in converted heat transfer . systems. Therefore, a regulation which specifies no PCBs in a system will create unnecessary hardships which are not warranted by the hazard to human health. Extensive studies should be conducted by the Adminis tration to determine the realistic acceptable level which can be achieved, and the regulation should specify this level. The period for compliance, fol lowing the establishment of an acceptable level, should be of sufficient duration to assure its achievement. 3. More information should be developed concerning ana lytical methodology and migration rates before a PCB tolerance level is established for food packaging materials, 4. Provision should be made in the proposed regulation permitting the use of transformers and capacitors containing PCBs when installed in a manner which would prevent direct contact with the food or animal feed being processed. 5. These comments are premised upon the statement by the FDA that "...the current dietary level of PCBs is not considered an immediate hazard to the public health." I. GENERAL DISCUSSION Monsanto Company has been a manufacturer of various chemi cals and other products since 1901, At the end of last year, Monsanto was the third largest chemical company in the United States. For many years we have supplied chemi cal products to almost every American industry, and, in fact, through our research departments have played a role in the development of technology in many industries. On some occasions, a chemical compound with specific properties is developed to meet a need in a certain appli cation. At other times, whether through innovative re search or by happenstance, a chemical compound with unique properties is developed first and then applications are found for which the new compound is uniquely suited. osw 019018 STLCOPCB4005562 Department of Health, Education and Welfare July 14, 1972 - Page 3 So it was in a sense with polychlorinated biphenyls, PCBs were apparently first uBed commercially in the late 1920's. PCBs are chemical compounds with Beveral very desirable qualities. They are very inert, substantially fire resistant and non-conductors of electricity. As the properties of these new compounds became known, they were put to use in applications where they seemed to be ideally suited. Perhaps the first of the uses was as a dielectric fluid in transformers and capacitors. In situations where high voltage arcing could occur, the fire resistant and insulating qualities of PCBs were highly desirable, Monsanto's production of PCBs began in the mld-1930's. As the desirability of PCBs gradually increased for many applications so did production of the material. Their fire resistant nature made them excellent choices for use as heat transfer fluids. Their inertness gave long lasting qualities to lubricants. When used as ingredients in coatings, they improved the waterproofing characteristics. Insofar as handling of the material is concerned, PCBs are considered less toxic than many other chemicals in everyday use. Recently questions have been raised concerning the effect of PCBs on the environment. The persistent nature of the products, while so desirable from the standpoint of many Industrial applications, began to work against them. In the late 1960*8, after sophisticated analytical pro cedures were developed which would determine minute quan tities of PCBs, they were detected in the environment. It was later learned that PCBs could affect certain forms of marine, terrestrial and avian wildlife. Early evidence indicated that, like DDT, PCBs did not readily biodegrade in the environment. Recently it has been established that many PCBs are biodegradable, particularly the monochloro, dichloro and trichloro, with evidence that some of the tetrachloro and pentachloro also degrade. When questions first began to be raised about the effects of PCBs on the environment, Monsanto, in the light of developing data, reviewed again the products and applications OSW 019019 STLCOPCB4005563 Department of Health, Education end Welfare July 14, 1572 - Page k in which they were used. While the environmental effect of PCBs was still in controversy, Monsanto began unilat erally to take steps intended to reduce the entry of PCBs into the environment. Acting on its own, Monsanto stopped the sale of PCBs for use in plasticizer applica tions such as paints, sealants and coatings. A program was initiated for reducing the sale of PCBs which pro vided that sales would be made only for use in applica tions where (a) the products were necessary from the standpoint of the public interest, and (b) no acceptable alternatives were available. Since sales as plasticizers had already been eliminated, the extended program further called for the termination of sales for use in hydraulic fluids and then the termination of sales for use in heat transfer fluids. Today, virtually all PCBs manufactured by Monsanto Company are used by the electrical industry for dielectric uses such as in transformers and capacitors; applications for which we understand there are, as yet, no satisfactory alternate products. The manufacturing and sales reduction program undertaken by Monsanto was completely unilateral and not because of any governmental requirement. The subject regulations being proposed by the FDA will be the first significant governmental regu lations affecting PCBs. II. TEMPORARY FOOD TOLERANCES Monsanto's current program on the sale of PCBs should In time virtually eliminate the contamination of foods (assuming no other commercial sources are available). During the interim the establishment of temporary tolerances for the proposed limited group of foods has merit. Past incidences of PCBs in foods, at levels considered to be unacceptable, have been relatively few, have been attributed to unusual single sources and, in virtually every case, the source has been identified. Additionally, we know of no facts that indicate that the action level guidelines established for milk in 1969 at 5.0 parts per million on a fat basis and for poultry in 1970 at 5.0 parts per million in edible portions hove not provided adequate protection to the consumer, We, therefore. osw 019020 STLCOPCB4005564 Department of Health, Education and Welfare July 14, 1272 - Page 5 conclude that the proposed temporary tolerances of 2,5 parta per million on a fat basis for milk and 5,0 parts per million on a fat basis for poultry do not appear to be Justified and we respectfully urge that the levels be maintained as originally established. III, PROCESSING EQUIPMENT Monsanto basically agrees with the objectives of the pro posed regulations relating to the use of PCBs in heat transfer systems in food, feed, and food packaging material plants. In 1971 we discontinued sales of PCBs to these applications and have recommended conversion to other available fluids, A copy of a bulletin available to our customers to assist them in their conversion is attached. You will note on page 12 our statement that heat transfer fluids are intended only for indirect heating purposes. The food industry requires high temperatures in certain of its operations to properly process its products and to protect the consumer from the dangers of pathogenic micro organisms from products prepared in an unsatisfactory manner, *1116 continued uBe of existing heat transfer systems must, therefore, be assured to prevent serious disruption to the nations food distribution chain. The regulation as proposed prohibits the presence of any PCBs in a system. Our limited experience with converted Monsanto Company units, which are not food related, indicates that, although considerable care is taken, some PCBs still remain in the system. The amount seems to vary with such factors as the design of the system, the age of the system, and the operating conditions involved. No generalization can be made relating to the levels of PCBs remaining in any given system.even though our former PCB heat transfer customers have been cautioned to remove PCBs from their systems. Under such conditions, the regulation as pro posed could deny the food industry the continued use of its facilities and would make more difficult the achieve ment of desired processing results. DSW 019021 STLCOPCB4005565 Department of Health, Education and Welfare July 14, 1972 - Page 6 Before promulgating this section of the regulations, we urge that extensive studies be conducted by the Adminis tration to determine the acceptable residual level of PCBs which can be realistically achieved in well run, pro perly managed systems. Following the establishment of this level, reasonable time, which we feel is considerably longer than the 30 days proposed, should be permitted to provide the food industry an opportunity for its orderly achievement. IV. FOOD PACKAQINQ MATERIAL The proposed regulations contain a maximum tolerance level of five parts per million PCBs which would be allowed in food packaging material. The proposal of any standard for packaging materials at this time would appear to be Ill-conceived. There are at least two areas in which more information must be developed before a reasonable PCB tolerance level can be established. First, accurate methoddlogy for use in determining the exact levels of PCBs in the various materials used in packaging must be developed. Second, it is necessary to determine the actual rate of migration of PCBs from each packaging material into foods. Since the composition of various materials used in packaging foods varies to a considerable extent, this information must be developed with respect to a number of different materials. It may be that some materials contain no PCBs at all, while other materials which do contain PCBs prevent their migration into foods. In either case, a PCB tolerance level for the packaging material would appear to be unnecessary. In any event, more infor mation should be developed concerning analytical methodology and actual migration rates before a PCB tolerance level is established for food packaging materials. ' V. CAPACITORS AND TRANSFORMERS The importance of continuing the use of PCBs as a dielectric fluid in capacitors and transformers has been generally acknowledged. Recent reports supporting this use include the Interdepartmental Task Force on PCBs report entitled OSW 019022 STLCOPCB4005566 Department of Health, Education and Welfare July 14, 1972 - Page 7 "Polychlorinated Biphenyls and the Environment" dated May, 1972 and the Food and Drug Administration's "Environ mental Impact Statement - Notice of Proposed Rule Making Polychlorinated Biphenyls" dated May 8, 1972. In the food processing Industry there are a number of applications of PCB-type electrical devices which cannot be adequately performed by substitutes. The hermatically sealed construction of capacitors and transformers, the very low failure rates, 0.1# to 0.2# per year, the exceedingly low failure rate which could lead to loss of fluid, approxi mately 0.01#, and the existence of lost electrical function, which would also occur on equipment failure signaling the operating personnel to take appropriate actions, are all characteristics which would tend to preclude food contamina tion. Banning of PCB-containing capacitors and transformers in factories engaged in food, animal feed,or food packaging materials would result in extensive rebuilding, relocating and re-equipping programs, all without demonstrable need. Monsanto, therefore, does not believe that the use of PCBcontaining capacitors and transformers in food plants should be arbitrarily denied and wholeheartedly supports the pro posals relating to this rule making submitted for your consideration by the General Electric Company, the Aerovox Corporation and the Certified Ballast Manufacturers Association. Our purpose in making these comments Is to aid the Adminis tration in developing realistic rules that will achieve the intended objectives without serious disruptions to the food industry and to the consumer. We believe the suggestions given above, if adopted, will serve this pur pose and we respectfully urge that they be given serious consideration, ' Respectfully submitted, WBP/bfc Attachment W. B. Papageorge Manager Environmental Protection SW 019023 STLCOPCB4005567 c TECHNICAL BULLETIN THERMINOL CONVERSION BULLETIN c Monsanto OSW 019024 STLCOPCB4005568 THERMINOL CONVERSION BULLETIN SP/ TC-1 "Nothing contained herein is to be construed as a recommendation to use any product in conflict with any patent. MONSANTO MAKES NO WARRANTIES AS TO THE FITNESS OR MERCHANTABILITY OF ANY PRODUCT REFERRED TO, no guarantee of satisfactory results from reliance upon contained information or recommendations, and disclaims all liability for any resulting loss or damage." Monsanto Industrial Chemicals Co. A Unit of Monsanto Company 800 N. Lindbergh Blvd., St. Louis, Mo. 63166 DSW 019025 1 STLCOPCB4005569 INTRODUCTION Therminol FR fire-resistant heat transfer fluids have long provided safe, dependable, economical performance for hundreds of users in dozens of applications. The presence of poly-chlorinated biphenyl (PCB) in the Therminol FR formulation provided fire-resistance, giving Therminol FR an added margin of safety which was especially desirable in hazardous applications. Most recently, PCB has been identified as a potential hazard to the environment. Monsanto has accordingly elected to discontinue the manufacture and sale of Therminol FR fluids for heat transfer appli cations. This bulletin is to inform you about two alternative products sold by Monsanto which do not contain PCB, namely Therminol 55 and Therminol 66. These products offer most of the excellent heat transfer characteristics of Therminol FR fluids, and even a few additional advantages, such as a lower specific gravity for improved pumpability requiring less horsepower. We would point out that Therminol 55 and 66 are not fire-resistant to the extent the Therminol FR fluids were, and due consideration must be given this fact in converting to these newer Therminol fluids. You may wish to consult with your insurers on any conversion from Therminol FR. Conversion from a Therminol FR fluid to a Therminol 55 or 66 fluid will be a relatively simple, low-cost procedure in the majority of cases. Incorporation of proper fire protection equipment will be the only consideration of major consequence in most cases. But even this modification becomes academic, for with the discontinuation of Therminol FR fluids, fire protection equipment becomes necessary for any and all low pressure heat transfer media available today, since the Therminol FR fluids were unique in their fire-resistance. Should questions arise with respect to the conversion from Therminol FR fluid, Monsanto's Specialty Products Group invites you to call upon its staff or qualified systems engineers for consultation at any time. Call . . . (314) 694-2514 and ask for a Monsanto Heat Transfer Specialist. DSW 019026 STLCOPCB4005570 it Therminol 55 and 66 and Your Heat Transfer System Table 1 shows the typical physical, chemical and thermal properties of Therminol FR-1, Therminol 55 and Therminol 66. As you will note, Therminol 55 and 66 are quite similar except with regard to AIT, Fire Point and density. The substantially lower density of Therminol 55 and 66 means that pumps used in a Therminol FR-1 system should be adequate for a Therminol 55 and 66 system. In most cases, pumping rates will be increased with a resultant saving in horsepower require ments. TABLE 1 TYPICAL PHYSICAL, CHEMICAL & THERMAL PROPERTIES Composition Maximum Bulk Temperature Rating (F.) Recommended Use Range (F.) Therminol FR-1 Polychlorinated Biphenyl 600F. Therminol 66 Modified Terphenyl 650F. Therminol 65 Alkylated Aromatic 600 F. 45 - 575F. 45 - 635F. 20 - 575F. Pour Point (F.) Pounds/Gallon (75F.) Flash Point (F.) Fire Point (F.) AiT (F.) Boiling Range (F.) Molecular Weight Expansion Coefficient cc/cc/F. 2 11.55 350 None to Boiling 1206F. 620 - 680 265 0.00031 -15 8.35 355 374 - 392 705 644 - 745 240 0.00039 ^10 7.4 355 410 670 635 - 734 340 0.00047 Therminol 55 and 66 have outstanding heat transfer properties, so heating and cooling performance will not be sacrificed in a change from Therminol FR-1. The specific heat and thermal conductivity of Therminol 55 and 66 are shown, along with other physical properties, in Tables 2, 3 and 4, and in Figures 1, 2 and 3, The lower pour points of Therminol 55 and 66 will provide easier cold startup of the system. DSW 019027 3 1 STLCOPCB4005571 ) Tamparature F C 50 10 100 38 150 66 200 93 250 121 300 149 350 177 400 204 450 232 500 260 550 288 600 316 650 343 700 371 TABLE 2 THERMINOL FR-1 VARIATION OF PROPERTIES WITH TEMPERATURE Density lb/gal 11.68 11.46 11.22 10.99 10.76 10.53 10.30 10.07 9.83 9.60 9.37 9.14 8.91 8.68 Kg/m3 1399.6 1372.7 1343.7 1316.7 1289.1 1261.3 1233.5 1205.8 1178.0 1150.2 1122.5 1094.7 1066.9 1039.3 Specific Halt Thermal Conductivity BTU/lb Koal/Kg BTU/fl Koal/m F C hr F hr C 0.272 0.282 0.291 0.3047 0.3151 0,3255 0.3359 0.3464 0.3568 0.3672 0.3776 0.3880 0.3985 0.4089 0.272 0.282 0.291 0.3047 0.3151 0.3255 0.3359 0.3464 0.3568 0.3672 0.3776 0.3880 0.3985 0.4089 0.06098 0.06060 0.06021 0.05976 0.05927 0.05875 0.05819 0.05760 0.05697 0.05630 0.05560 0.05487 0.05409 0.05329 0.0907 0.0902 0.0896 0.0889 0.0882 0.0874 0.0866 0.0857 0.0848 0.0838 0.0827 0.0817 0.0805 0.0793 Vliootlty Cp 308 23.2 6.6 3.4 2.3 1.4 1.0 0.8 0.6 0.5 0.4 0.4 0.3 0.3 Cs 220 16.9 4.9 2.6 1.8 1.1 0.8 0.7 0.5 0.4 0.4 0.3 0.3 0.3 Vapor Preiture mmHg abioluta _ _ _ _ _ _ Kg/cm2 _ _ _ _ _ 10 0.0136 27 0.0367 65 0.0884 143 0.1945 291 0.3958 550 0.7480 18.8psia 1.3218 31.9psia 2.2429 Temperature F C 0 50 10 100 38 150 66 200 93 250 121 300 149 350 177 400 204 450 232 500 260 550 288 600 316 650 343 700 371 TABLE 3 THERMINOL 66 VARIATION OF PROPERTIES WITH TEMPERATURE Denitty lb/gal 8.67 8.51 8.34 8.14 7.91 7.77 7.59 7.39 7.17 7.04 6.75 6.62 6.42 6.24 6.09 Kg/m3 1040 1020 1000 975 950 930 910 885 860 840 810 793 770 750 730 Specific Haat Thermal Conductivity BTU/lb Koal/Kg BTU/ft Kcal/m F C hr F hr C 0.320 0.350 0.380 0.405 0.430 0.455 0.480 0.505 0.530 0.555 0.580 0.605 0.630 0.655 0.680 0.320 0.350 0.380 0.405 0.430 0.455 0.480 0.505 0.530 0.555 0.580 0.605 0.630 0.655 0.680 0.0720 0.0711 0.0703 0.0695 0.0687 0.0678 0.0670 0.0662 0.0653 0.0645 0.0637 0.0628 0.0620 0.0613 0.0605 0.1072 0.1058 0.1046 0.1034 0.1022 0.1008 0.0997 0.0985 0.0972 0.0959 0.0948 0.0935 0.0923 0.0912 0.0900 Vliootlty Cp 62000 255 28.0 9.75 4.18 2.42 1.55 1.06 0.77 0.58 0.45 0.36 0.34 0.27 0.20 Ct 50000 250 28.0 10.0 4.40 2.60 1.70 1.20 0.90 0.69 0.55 0.46 0.44 0.36 0.28 Vapor Prattura mmHg abioluta ___ Kg/om2 _ -- ___ -- -- 0.1 -- 2.0 -- 20.0 50.0 100.0 200.0 350.0 760.0 1000 ___ ___ ___ ___ 0.003 -- 0.027 0.068 0.136 0.272 0.476 1.034 1.360 DSW 019028 4 STLCOPCB4005572 Temp*reture F "C 0 -18 100 38 200 93 300 149 400 204 500 260 600 316 TABLE 4 THERMINOL 55 VARIATION OF PROPERTIES WITH TEMPERATURE Der lity Ib/gel 7.62 7.31 7.00 6.69 6.39 6.07 5.76 Kg/m3 915 878 840 803 766 729 691 Specific Heel Thermel Conductivity BTU/lb Kul/Kg BTU/ft Kcel/m F C hr F hr C 0.420 0.472 0.522 0.572 0.620 0.670 0.718 0.420 0.472 0.522 0.572 0.620 0.670 0.718 0.0813 0.0784 0.0753 0.0724 0.0692 0.0661 0.0630 0.1210 0.1167 0.1121 0.1077 0.1030 0.0984 0.0938 Vleoetity Cp 1472 25.4 4.20 1.69 0.904 0.583 0.415 Ct 1610 30.1 5.0 2.10 1.18 0.80 0.60 Vapor Prenur* mmHg ibtoiute Kg/om* 0.5 3.0 10 40 100 250 0.001 0.004 0.014 0.054 0.136 0.330 FIGURE 1 THERMINOL fR-1 PHYSICAL PROPERTIES t 16 t 14 zo Ocn' m 12 O a< oIf 10 p 0QQ0 r> z CD 80Ui (ZD QUJ > fOD-- ooz 6 4 VOO) o --------------------------------------------------------------------- ------------ -- ....-- . ---- --50 0 100 200 300 400 500 600 700 -J 5< a: UJ TEMPERATURE -- F. X 0SW 019029 STLCOPCB4005573 FIGURE 2 THERM1N0L 66 PHYSICAL PROPERTIES . t 40 t 35 O<n' 30 <o cffrii ex X '-- 25 fm-- 20 izUonJ t > 15 i-- o3 10 o z 5 --50 0 100 200 300 400 500 600 700 TEMPERATURE -- "F. c<c 0 XUJ FIGURE 3 THERMINOL 55 PHYSICAL PROPERTIES . t 40 35 30 25 20 15 10 5 0 VISCOSITY-- CENTISTOKES VISCOSITY -- CENTISTOKES OSW 019030 STLCOPCB4005574 Generally speaking, then, a well designed system currently operating on Therminol FR-1 can be converted to Therminoi 55 and 66 with few, if any, basic changes in design -- and without sacrifice to heat transfer efficiency. With the similarity of the heat transfer properties of the three fluids thus established, let us turn to the important differences between Therminol FR-1 and Therminol 55 and 66: namely, fireresistance and oxidation-resistance. Fire-Resistance As stated in the Introduction to this bulletin, the Therminol FR fluids were unique in their inherent fire-resistance. No other commonly used heat transfer medium could be so classified. Even so, the Therminol FR fluids could be made to burn under certain conditions, as indicated by their AIT of about 1200F. It is important to realize that Therminol 55 and 66 are less fire-resistant than Therminol FR-1, and to modify the heat transfer system accord ingly; it is equally important to understand that Therminol 55 and 66 are not volatile, highly flammable fluids, but rather combustible as defined by FM and NFPA (NFPA No. 821). Protecting the System There are two major fire protection considerations in changing to Therminol 55 or 66 -- system leakage and possible tube rupture (in the heater). The former is actually part of the larger subject of good system maintenance, and should be considered regardless of the heat transfer medium employed. A tight, well-maintained system is usually a good, safe system! Following are some suggestions to prevent leakage when you convert to Therminol 55 or 66. First, if your system has rotary mechanical seals, you should provide a spray shield and a drip pan with a drain to a collection sump. Canned and seal-less pumps offer excellent protection against leakage. The best way to prevent piping leakage is to weld all connections. Where you must have access, use raised-face flanges with appropriate gasketing and high-temperature bolting. Control of piping leaks is especially important, since fluid-soaked insulation poses a more serious hazard than the leaking fluid, itself. Organic compounds such as Therminol 55 and 66 exhibit a slow oxidation reaction with the air trapped inside the voids of the in sulating material when system temperatures reach about 500F. Saturated insulation offers a large fuel surface in the face of poor heat dissipation conditions, and this, along with possible catalysis from the insulating material (magnesia, silicate-bonded asbestos or calcium silicate) can cause a temperature build-up in the mass. This temperature build-up can result in ignition of the fluid when the space between the piping and the saturated insulation is exposed to air (i.e., should the insulation be broken for repair, etc.). This phenomenon is not fully understood, but appears to occur less with closed cell insulation than with the insulating materials mentioned DSW 019031 7 STLCOPCB4005575 above. Closed cell materials, then, are preferred, especially where leakage is a possibility despite all precautions. The principle problem areas are near instrument connections, valve packing glands, flanges, and where cracks develop in relatively im permeable insulation cement adjacent to oil soaked insulation. To obviate this problem, eliminate any source of leakage promptly. Replace leaky gaskets, oil soaked insulation, and re-pack valve stems. Cover insulation where leaks might occur with a hydraulic setting, oil-resistant cement. Install valves, where possible, with the stems in a horizontal position so that leaks will drip away from the insulation. And again, use closed cell insulating materials on suspect piping areas. Tube Rupture in Fired Heaters Generally speaking, where fire protection is concerned, it is best to consult your insurance underwriter for guidance and counsel. Likewise, you will want to discuss your fire safety equipment requirements with qualified suppliers of fire protection equipment. Selection and sizing of fire protection equipment is important to safeguard the installation. A commonly used method of preventing fire in the event of tube rupture in fired heaters is piping steam or C02 as a snuffer into the combustion chamber of the heater. Usually a properly-sized line with a remote manual valve for activation is the preferred arrangement. This snuffer system could be automated by the use of an exhaust stack temperature switch. This switch would then energize a solenoid valve and alarm upon excessive temperature rise, automatically flooding the chamber with a fire extinguishing agent. In practice the temperature switch is often set about 100F. over the normal exhaust temperature to prevent nuisance shutdowns. Where steam snuffer systems are used, it is a good idea to employ a steam trap to avoid slugging the combustion chamber with water when the system activates, or is activated manually. You can obtain a basic guideline in the selection of C02 protection equipment (again, it is best to consult your insurance underwriter) from the National Fire Protection Assn,, 60 Batterymarch Street, Boston, Mass. 02110 AC 617-482-8755. NFPA Bulletin No. 12 dated 1968 should be requested. This bulletin should be helpful in determining the amount of COs and the concentration of C02 needed to extinguish a fire based on your specific application. C02 cylinders are available from Cardox Division of Chemetron, Chicago, 111. as well as other suppliers. Some standard sizes are 50, 75, 100 and 150 pound cylinders. Prices usually include drawings of the units, fully charged cylinders, flexible piping connectors, spray nozzle, pressure switch, alarm and automatic control, provided C02 release signal is supplied by customer device. Piping, wiring, and installa tion labor to be provided by the customer. Recharging of spent cylinders is available at an additional cost from a variety of "Fire & Safety Equipment Suppliers" listed in the Yellow Pages of your phone book. OSW 019032 V STLCOPCB4005576 I Selection of all equipment and installation recommendations should be obtained from qualified suppliers; however, it is important to insure that sufficient C02 is available to prevent re-ignition while the heater is cooling. The Halon Fire Suppression System is a possible alternative to a C02 arrangement because it can be used in closed spaces with personnel in the area. One supplier of Halon systems is the Cardox Division of Chemetron Corporation, Chicago, 111. 60611. Again, we strongly recommend that the advice of fire protection companies be solicited in either case to insure proper equipment selection and installation. If steam is to be used rather than the other alternatives suggested above, please refer to the NFPA Volume I, Section 86A (1970-1971) to obtain the volume of steam required. Oxidation-Resistance With a Therminol 55 or 66 system, some provision should be made to prevent oxidation caused by air contact at fluid temperatures exceeding 200F. This was not the case with Therminol FR fluids, but must be observed for Therminol 55 and Therminol 66. Oxidation can result in sludge formation, eventually leading to carbonaceous deposits on heat transfer surfaces and at mechanical seal faces. Oxidation of fluid can develop by air contact in an open, vented expan sion tank. Therefore, we recommended that the expansion tank be blanketed with an inert gas (such as nitrogen) as shown in Figure 4. If this is not possible, air contact can be minimized by a cold seal arrange ment as shown in Figure 5. An inert gas pressure of one to two psi is adequate, as Therminol 55 and 66 do not require pressurization to maintain liquid phase. FIGURE 4 SUGGESTED INERT GAS ARRANGEMENT FOR EXPANSION TANK RUPTURE DISC (OPTIONAL) CXf----o--~ PUMP OSW 019033 9 STLCOPCB4005577 FIGURE 5 SUGGESTED COLD SEAL TRAP ARRANGEMENT FOR EXPANSION TANK You can design the cold seal arrangement, quite simply by piping the expansion tank vent to a second tank where the vent line projects subsurface and can be flooded with additional Therminol 55 or 6G to minimize air contact in the expansion tank vapor space. In converting from Therminol FR to Therminol 55 or 66, it is important to remember that many Therminol FR systems were designed with a hot bleed line into the expansion tank to eliminate moisture accumula tion. Moisture accumulation in the presence of hydrogen chloride gas released during the decomposition of the FR fluids could contribute to acidity problems. This is not the case with Therminol 55 or 66; there fore, this bleed line should not be used during normal operation of a Therminol 55 or 66 system. This line should be valved off during opera tion but it could be retained as a convenient means of venting the system during initial startup after conversion. Further protection against a hot expansion tank occurrence would be the removal of any expansion tank insulation and feeder line insulation. Carbonaceous deposits can also occur at the pump seal face due to leakage at high temperatures. The use of a seal flush system or a double mechanical seal is helpful in preventing excessive seal wear. Converting to Therminol 55 and 66 With fire-protection and oxidation-resistance procedures well in mind, let us turn to the matter of preparing the Therminol FR system for Therminol 55 or 66. Accumulation of debris over the years in the system could cause serious problems, especially to mechanical seals, rotary joints, etc. All heat transfer systems should be cleaned from time to time as a part of normal preventive maintenance. Since a fluid change is neces- OSW 019034 9 STLCOPCB4005578 sary at this time, it would seem practical to use the downtime to thoroughly clean the system prior to startup on a fresh charge of fluid. We strongly advise you not to simply drain and change, but to take this opportunity to clean your system. Many potential problems will be prevented by so doing. Another reason for cleaning your system at this time is to assure com plete removal of the Therminol FR fluid. A system cleanout is the only sure way to do so. How to go about the cleanout is a matter of choice, but here are some alternatives for your consideration: A. Fluid Flush Cleaning This method is probably the fastest and most effective where heating surfaces are not heavily fouled. It also offers the advantage of not having to introduce foreign chemicals into the system. With this method, the system is drained of Therminol FR, re-filled with Therminol 55 or 66, operated for a reasonable period of time, drained once again, and finally, recharged with fresh Therminol 55 or 66. Both the drained Therminol FR and the Therminol 55 or 66 used to flush the system may then be returned to Monsanto for disposal. B. Solvent Chaning This method is satisfactory for cleaning a slightly soiled system, but chlorinated solvents must be avoided. Typical solvents used are benzene, and xylol (caution should be used with low flash point solvents). Do not use trichlorobenzene or perchloroethylene. (CAUTION: ALL SOLVENTS SHOULD BE COMPLETELY REMOVED FROM THE SYSTEM PRIOR TO OPERATING AT HIGH TEMPERATURES). Normally this is accomplished by drying the residual with warm air or by operating the refilled Therminol system at a temperature slightly above the boiling point of the solvent until the residual is vented from the system. Some caution should be used in drying the system to prevent flashing of the solvent with resultant discharge of Therminol from the system. Both the drained Therminol FR and the flushing solvent may then be returned to Monsanto for disposal. Fluid Disposal Monsanto offers an incineration service for the disposal of PCB heat transfer fluids and the flushing fluids mentioned above. For details of this service and how to return fluids to Monsanto for disposal, please write: Monsanto Company P.O. Box 14617 St. Louis, Missouri 63178 ... or call (314) 694-2514 and ask for a Monsanto Heat Transfer Specialist. DSW 019035 11 STLCOPCB4005579 Handling: General Information Heat transfer fluids are intended only for indirect heating purposes. Under no circumstances should any Therminol heat transfer fluid be allowed to come in contact with or in any way contaminate food, animal feed, food products, food packaging materials, food handling equipment, pharmaceuticals or any food-related items. Therminol 55 and Therminol 66: Safety of Handling According to the definitions of the U.S. Federal Hazardous Substances Labeling Act, Therminol 55 and 66 are not toxic substances since the oral and dermal lethal doses in animals are greater than 5 grams per kilogram of body weight. Additional animal studies indicate that they do not have significant skin or eye irritation potential. It is suggested however, that good industrial practice relating to the avoidance of repeated and prolonged skin contact to any industrial chemical, heat transfer fluids, or petroleum product be followed. Therminol 55 and 66 have such low vapor pressures at ambient temper ature that inhalation of vapors during transfer of fluid from shipping containers to a heat transfer system presents no hazard. Vapors emitted by either fluid at elevated temperatures may be irr itating as would be the case with excessively heated petroleum oils. In heat transfer installations, the fluids are used in a closed, unpressurized system free from leaks and with the expansion tank vent trapped so as to condense any vapors and thus prevent their escape to the work environment. Consequently, there should be little or no opportunity for workers to experience any contact or exposure. While it is believed that Therminol 55 and 66 pose no serious problems with respect to the environment, as a concerned supplier to industry, Monsanto urges the user to maintain a tight system, to correct leakage promptly, and to exercise care in the handling and disposal of this and all other such products. A tight maintenance program not only protects the environment, but keeps employes comfortable, the working area clean, and the system running smoothly. OS W 019036 ?.-32b3-0l72-6 Ulho in U S.A. STLCOPCB4005580 CUSTOMER SERVICE CENTERS AKRON. OHIO 44313 260 Springside Drive Montrose Development Park Tei. (216) 666-4111 __ ATLANTA, GEORGIA 30339 320 Interstate North Parkway Suite 500 Tel. (404) 432-7111 BOSTON, MASSACHUSETTS 02149 Everett Station Tei. (617) 387-5010 CHICAGO, ILLINOIS 3158 Des Plaines Ave. Des Plaines. Illinois 60018 Tel. (312) 296-6688 CINCINNATI, OHIO 45206 1501 Madison Hoad Tel. (513) 751-6707 DETROIT, MICHIGAN 500 Northland Towers West Southfield, Michigan 48075 Tel. (313) 357-0910 HOUSTON, TEXAS 77027 1301 Post Oak Tower 5051 Westheimer Hoad Tel. (713) 621-9550 LOS ANGELES, CALIFORNIA 90022 6670 E. Flotilla St. Tel. (213) 723-2492 NEW YORK, NEW YORK 10036 1114 Avenue of the Americas Tel. (212) 764-5000 ST. LOUIS, MISSOURI 63166 800 N. Lindbergh Blvd. Tel. (314) 694-1000 SAN FRANCISCO BAY AREA 2710 Lafayette Santa Clara, California 95052 Tel. (408) 243-0414 SEATTLE, WASHINGTON 98121 2112 Third Avenue Tel. (206) 622-4203 WILMINGTON. DELAWARE 19810 Suite 204, Bancroft Bldg. 3411 Silverside Hoad Tel. (302) 478-4600 Monsanto Industrial Chemicals Co. A Unit of Monsanto Company 800 N. Lindbergh Blvd., St. Louis, Mo. 63166 12/71 J Monsanto DSW 019037 STLCOPCB4005581 ) ) DSU 019038 Monsanto 800 N. LINDBERGH BLVD., ST. LOUIS, MISSOURI 63166 ) STLCOPCB4005582