Appendix B

Carbamate Pesticide and Methyl Isocyanate Timeline

4 June 1954: Acrolein tank car explosion and 1955 ethylene oxide distillation column explosion at the Institute site led to the establishment of the Union Carbide Reactive Chemicals employee awareness training program and the Kanawha Valley Emergency Planning Committee.

1958: Carbaryl (Sevin) commercialized by Union Carbide (UCC); production by chloroformate process (phosgene + 1-naphthol → 1-naphthol chloroformate; naphthol chloroformate + methylamine → carbaryl) (None of the intermediates were made at Institute).

5 January 1961: First shipment of carbaryl from Institute.

1966: Methomyl introduced (and registered in 1968) by DuPont; production by isocyanate process (methomyl oxime + methyl isocyanate → methomyl).

1966: UCC startup of MIC Unit 1 for use in carbamate pesticides (other than carbaryl).

1976: UCC aldicarb (Temik) production started in Institute East Carbamoylation Center; production by isocyanate process (aldicarb oxime + methyl isocyanate → aldicarb).

April 1978: UCC startup of new Syngas plant and MIC Unit 2 (Total Unit 1 and Unit 2 capacity: 42M lb/yr MIC).



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Appendix B Carbamate Pesticide and Methyl Isocyanate Timeline 4 June 1954: Acrolein tank car explosion and 1955 ethylene oxide distillation column explosion at the Institute site led to the establishment of the Union Carbide Reactive Chemicals employee awareness training program and the Kanawha Valley Emergency Planning Committee. 1958: Carbaryl (Sevin) commercialized by Union Carbide (UCC); production by chloroformate process (phosgene + 1-naphthol → 1- naphthol chloroformate; naphthol chloroformate + methylamine → carbaryl) (None of the intermediates were made at Institute). 5 January 1961: First shipment of carbaryl from Institute. 1966: Methomyl introduced (and registered in 1968) by DuPont; production by isocyanate process (methomyl oxime + methyl isocyanate → methomyl). 1966: UCC startup of MIC Unit 1 for use in carbamate pesticides (other than carbaryl). 1976: UCC aldicarb (Temik) production started in Institute East Carbamoylation Center; production by isocyanate process (aldicarb oxime + methyl isocyanate → aldicarb). April 1978: UCC startup of new Syngas plant and MIC Unit 2 (Total Unit 1 and Unit 2 capacity: 42M lb/yr MIC). 157

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158 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 1978: UCC carbaryl production changed to isocyanate process (phosgene + methylamine → methyl isocyanate; methyl isocyanate + naphthol → carbaryl) in Institute East Carbamoylation Center; isocyanate process claimed to involve higher overall yields, fewer losses from hydrochloride adduct by-products, less waste and environmental impact, and fewer and less severe corrosion problems. 1978: Sophisticated drum-filling operation enables MIC to be shipped to cus- tomers in France, India, Brazil, and United States. Literature describes four general routes to carbaryl (http://www.exchemistry.com/ sevin.html): 1. 1-naphthol + phosgene then + methylamine (chloroformate process), 2. 1-naphthol + methyl isocyanate (isocyanate process), 3. 1-naphthol + methyl carbamoyl chloride, and 4. 1-naphthol + dimethyl urea. In principle, these four approaches may also apply to any of the carbamates; as far as is known, however, only the chloroformate process was used as an alterna - tive to the isocyanate process, and that was for carbaryl, and that was abandoned. 1979: UCC shuts down MIC Unit 1 because of lower projected demand. 1984: UCC methomyl and Larvin production started using isocyanate process in Institute West Carbamoylation Center on old olefins site. 1984: Toluene diisocyanate site converted to Miscellaneous Carbamates Unit for aldicarb, Standak, Broot, and Zectran. 3 December 1984: Bhopal accident. 1985: MIC destruction capacity and other safety enhancements added at Institute. 23 April 1985: Boros (UCC) report on possible research alternatives: 1. Aqueous medium for aldicarb oxime + MIC reaction (similar to DuPont 1970 patent). 2. Onepot process for aldoxycarb (aldicarb oxime + methyl isocyanate (water) → aldicarb; aldicarb + H2O2/HCOOH → aldoxycarb [Standik]). General process for carbamates: ROH + CO + CH3NH2 (Pd/O2) → 3. carbamate + H2O (caustic, chlorine, phosgene, MIC eliminated; need high Pd productivity and recovery) (based on Asahi Chemical article in Journal of Organic Chemistry, 1984).

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159 APPENDIX B 4. Use of MIC/NaHSO3 solid adduct (reported 27 July 1976) instead of MIC demonstrated for carbaryl, aldicarb, methomyl, and carbofuran. 5. Conversion of methyl formamide to MIC over dehydrogenation catalyst (Sun Ventures & DuPont, 1976). 6. Review of 55 MIC patents between January 1944 and July 1979 reveal primary method of MIC production to be phosgenation of methylamine followed by either (a) HCl removal by some separation technology, or (b) HCl removal by reaction with an acid receptor. NaOCN + dimethyl sulfate → MIC + sodium sulfate (cyanate process) 7. (Deutsche Gold patent; operated by Sunko, June 1980). June 1985: DuPont, given loss of availability of bulk MIC, develops methyl for- mamide oxidation process for MIC(g) production and integrates with continuous methomyl process for minimum MIC inventory. 11 August 1985: Accidental release of aldicarb oxime and methylene chloride in Miscellaneous Carbamates Unit (aldicarb plant) (Lead in part to new OSHA safety program for chemical plants and EPA Chemical Emergency Preparedness Program). January 1986: FMC, given the loss of availability of bulk MIC, starts production of carbofuran (Furadan) (operated by UCC on old ethyl alcohol site) in Institute West Carbamoylation Center; production by isocyanate process (carbofuran phe - nol + methyl isocyanate → carbofuran). 1986: UCC updates MIC patent review (July 1979-December 1985); patent activ- ity shifting to MIC “carriers”: 1. Phosgenation of methylamine followed by pyrolysis of methyl car- bamoyl chloride (traditional route; little patent activity); 2. Phosgenation of ureas (Philagro); 3. Thermal decomposition of carbamic acid esters (Bayer, EniChemica); 4. Thermal decomposition of trisubstituted ureas (Bayer); 5. Thermal decomposition of oxazolidinones (Agency of Industrial Science and Technology); 6. Thermal decomposition of oxalamate (BASF); 7. Thermal decomposition of N-substituted acetylacetamides (Bayer); 8. Thermal decomposition of dialkylmalonamides (Bayer); 9. Thermal decomposition on N,N’-disubstituted allophanates (BASF); 10. Thermal decomposition of organosilicon intermediates (Soviet publications); 11. Thermal decomposition of reversible boron-MIC adducts (Vertac); 12. Dehydrogenation of N-methylformamide (DuPont); 13. Methylation of metal cyanate (Degussa, FMC);

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160 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 14. Acetyl chloride and sodium azide (USSR); and 15. Amination of chloroformate (Hungary). Recommended UCC research alkyl carbamates, boron compounds, and silyl carbamates. March 1986: UCC report on pyrolysis of aryl N-methyl carbamates to MIC. ~1986: UCC report on concept to react diphenyl carbonate and methylamine to make phenylmethylcarbamate based on EniChemica technology. October 1986: In a meeting with Nor-Am Chemical, UCC discloses that although it had been working on a phenyl methylcarbamate (and butylphenyl methylcar- bamate) process for shipment to make aldicarb at Woodbine, Georgia, Brazil, and France, it discovered that it could ship aldisol (aldicarb/methylene chloride solution) instead, and therefore was less interested in the phenyl methylcarbamate process. December 1986: Rhône-Poulenc (RP) buys Union Carbide Agricultural Products Division March 1987: Study by Schering Agrichemicals related to local Michigan pro- duction of carbamates given the loss of availability of bulk MIC (small scale: 1M lb/yr final product). Three basic approaches: 1. Via MIC from onsite MIC generation, 2. Via methyl carbamoyl chloride from methylamine phosgenation (with- out pyrolysis), or 3. Via methyl carbamoyl chloride from methyl formamide and sulfuryl chloride. In turn, three cases were considered for onsite MIC generation: 1. Sodium cyanate + dimethyl sulfate (Sunko); 2. Methyl formamide oxidation (DuPont); and 3. Diphenyl carbonate processes (two versions): a) Diphenyl carbonate + methylamine (EniChemica and Union Carbide), b) Diphenyl carbonate + dimethyl urea (Bayer). Concluded changing to EniChemica process had 5- to 6-year payback vs. contin - ued Sunko contract manufacture; recommended continue sulfuryl chloride route development.

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161 APPENDIX B April 1988: RP evaluates DuPont methyl foramide oxidation route to MIC production. October 1988: RP Project MN: 1. MIC vent gas incinerator, 2. Carbaryl reliability and optimization, 3. Comparison of UCC and RP syngas and phosgene technologies, and 4. MIC downsizing (use of new discrete simulator software package). 31 January 1989: RP Project MS (presentation to Perez and Robirds) (preparation of MIC and aldicarb at Woodbine to eliminate aldisol transport from Institute to Woodbine). Two MIC processes considered: 1. Cyanate process (NaOCN + dimethyl sulfate → MIC) (semibatch) Pros: Low MIC inventory (200 lb or less); dimethyl sulfate to be made by RP Cons: Dimethyl sulfate transportation; NaOCN availability; high vari- able costs; environmental protection concerns 2. DuPont methyl formamide oxidation process (methyl formamide + O2 → MIC + H2O) Pros: DuPont technology; cost depends on methyl formamide cost, but lower than cyanate process Cons: Need for pilot plant; Long development and startup time; lower MIC quality could risk lower aldicarb quality; needs “miracle” process and technology relationship with DuPont Also considered transfer of Woodbine formulation capabilities to Institute (except gypsum granulation) and maintaining existing MIC and aldicarb technologies in Institute; this was the preferred alternative 1989: RP consideration of Enichem technology for phenyl methylcarbamate technology for individual MIC production at each carbamate process. July 1989: RP discussion of two alternative routes to diphenyl carbonate for Enichem process: 1. Phenol phosgenation 2. Phenol + CO + O2 December 1989: RP further discussions of Enichem MIC technology at Institute 1. Manufacturing and inventory cost analysis, 2. Concept and objectives, 3. MIC generators/users interface,

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162 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 4. Quality program, and 5. Impact on plant operaion. Expected MIC inventories: 150 lb of methomyl, 300 lb of carbaryl, 50-300 lb of aldicarb. January 1990: RP considers MIC minimization (identified as “Bayer alterna- tive” based on diphenyl carbonate + dimethyl urea) as well as MIC containment alternatives. 10 July 1991: RP report on Enichem-RP technical meeting on dimethyl carbon - ate, diphenyl carbonate, and MIC 1. Dimethylcarbonate is made from methanol, CO, and O2 over Cu and Pd; 2. Diphenylcarbonate is either made from phenol and phosgene or phenol, CO, and O2, or by transesterification of dimethylcarbonate with phenylacetate; 3. Phenylmethylcarbamate is made from diphenylcarbonate and methyl- amine to be cracked at each carbamate process to MIC. December 1991: RP designs (but does not build) a new MIC plant for Institute based on phenylmethylcarbonate production, storage, and distribution to various carbamate processes to be cracked to gaseous MIC. 18 August 1993: An explosion in the methomyl/Larvin plant killed one employee and critically injured two others. RP was charged with 27 safety violations including failure to properly maintain, inspect, and test piping systems and other equipment. OSHA fined RP a record $1.6 million. 1993: RP conducts $50M Institute Modification Project (IMP) related to MIC, phosgene, and chlorine safety. Aspects include chlorine unloading, chlorine trans- fer, phosgene production, elimination of hard-to-clean small diameter piping, MIC refining system and phosgene separation system leak detection, water leak detection by analysis for CO2, reduce number of make tanks, field storage tank modifications, MIC transfer line changes, methylamine storage relocation, local storage of caustic for MIC destruction, standby emergency diesel electric genera- tor; allow MIC production unit to operate at reduced rates (700-4000 lb/hr); new MIC instrumentation; replace Crane canned pumps with external recirculation with Sundyne canned pumps with internal recirculation; radiation shields for MIC and Cl2 transfer lines near fire hazards; control room air safety; replace Karbate reboilers with tantalum; MIC make analyzers; piperack crossing barriers; MIC capacity reduced to 22M lb/yr.

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163 APPENDIX B 1994: RP MIC Risk Management Plan. Process design 1. Emergency dump tank available for safe transfer of product from leaking vessel, 2. Scrubber will destroy MIC from any storage tank, 3. Flare tower will destroy MIC vapors from process vents, 4. Backup control room instruments, 5. Automatic MIC isolation valves stop leaks, 6. Diking and spill collection sump, 7. Fire deluge system, 8. MIC leak detection alarms, 9. Safety relief valves protect vessels from over pressure, 10. Diesel generator for backup power, 11. Sealless pumps for pure liquid MIC, 12. Fire protection for pipe rack transfer lines, and 13. Independent nitrogen supply to prevent cross contamination. Equipment design 1. Double-walled underground storage tank, 2. Pressure vessels coded by ASME, 3. Blastmat protection on aboveground MIC storage facilities, 4. Stainless steel construction, 5. Pipelines over roads protected by barriers, and 6. Double-walled pipelines with leak detection analyzers on critical trans - fer lines. Safety reviews 1. Process hazard analysis completed every five years, 2. Ongoing safety reviews for design changes, 3. Operational reviews completed for all process changes, and 4. Safety review team includes safety experts, engineers, union operators, and union maintenance personnel. Procedures 1. Strictly enforced inventory limits, 2. Annual review of operating procedures, 3. Personnel safety procedures, and 4. Strictly enforced cross-plant transfer procedure. Training 1. Skilled union operators are trained and qualified, 2. Maintenance personnel are fully trained, and

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164 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 3. Hazard communications training provided for all personnel, including contractors. Mechanical Integrity 1. Periodic testing and inspections for tanks, columns, heat exchangers, pumps, instruments, pipes. Emergency Response 1. Dedicated in-plant Emergency Operations Center, 2. Trained Incident Commander onsite, 3. Trained emergency squad onsite at all times, 4. Plant-wide notification system, 5. Dispersion modeling system, 6. Regular meetings and coordination with community responders, 7. Onsite dispensary and doctor, 8. Periodic unannounced drills, 9. Courtesy notification to METRO of minor releases, and 10. Plant can activate community alarm (Good Samaritan Agreement). Incident Investigation 1. Formal investigations conducted for significant events, 2. Reporting procedures for all events, and 3. Conducted with operators, union, and safety representatives. Audits 1. In-plant audits, 2. Corporate audits, 3. Job observation, 4. Auditing for critical safety procedures, performed by each department, 5. CMA Responsible Care self-audits conducted annually, and 6. Ongoing risk assessment process. 12 August 1996: AgrEvo evaluation of Kuo-Ching (Taiwan) MIC production MIC made batchwise by cyanate process (NaOCN + dimethyl sulfate); two batch lines; 1000kg/batch; no overnight storage. Has/Does: Scrubbers, dump tanks, backup control room instruments, auto - matic MIC isolation valves, diking, fire deluge system, pressure relief valves, backup diesel power, gravity flow for MIC, mechanical seals on agitators, fire protection for transfer lines, periodic process hazard analysis, safety reviews for design and equipment changes, operational reviews for process changes, safety review team expertise, inventory limits, annual review of procedures, personnel safety procedures, enforced plant procedures, trained and qualified operators, trained maintenance, hazard communications, testing and inspection for leaks,

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165 APPENDIX B trained emergency squad, emergency notification system, coordination with com- munity emergency responders, unannounced drills, community alarm, formal incident investigation, reporting procedure, investigations conducted with opera - tors and safety representatives. Does Not Have/Do: Heat transfer fluid inert to MIC, MIC leak detection alarms, double-walled storage tanks, blastmat protection on aboveground storage tanks, double-walled pipelines, dedicated in-plant emergency operation center, onsite trained incident commander, onsite dispensary and doctor. AgrEvo expressed unspecified concerns over conditions of the MIC unit and a renovation was promised. March 1999: RP purchases FMC carbofuran and carbosulfan manufacturing facilities and establishes Carbamate Excellence Center. November 1999: RP begins production of new carbamate Oxamyl in Miscel- laneous Carbamates Unit. December 1999: Rhône-Poulenc agricultural products division merged with Hoechst Shering AgrEvo to form Aventis CropScience. October 2001: Aventis CropScience sold to Bayer to become Bayer CropScience. October 2002: Bayer conducts safety analyses of MIC and carbamate operations. 2002: Bayer MIC Inventory Reduction Conclusions. 1. Increased unavailability of MIC could lead to operational delays in con - suming units; 2. Limiting maximum MIC capacity would lead to increased shut down start up cycles for MIC unit; 3. Points 1 and 2 are inversely proportional; and 4. Forcing MIC inventory levels down appears feasible, but costly for MIC manufacture and downstream consumers. 28 August 2008: Bayer methomyl residue treater accident. May 2009: Carbofuran banned by the U.S. Environmental Protection Agency. 2009: Bayer MIC production 9M lb. 5 April 2009: House Energy and Commerce Committee asks U.S. Chemical Safety and Hazard Investigation Board to investigate alternative MIC technologies.

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166 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 26 August 2009: Bayer announces $25 M plant modification. Modification plan includes the following (Martin, 2011). Bayer MIC Unit Layers of Protection Primary measures: 1. Process design. 2. Equipment, piping, and instrumentation standards: a. Exotic materials of construction throughout the process to minimize corrosion. 3. Operator training and experience, mature, well-documented procedures. 4. Online analysis allows verification of MIC quality before adding to stor- age tank: a. MIC purity must be maintained to minimize the probability and rate of undesirable reactions; b. Multiple analyzers based on diverse technologies used to monitor MIC quality both before and after entering storage tanks; and c. Proper levels of adverse reaction inhibitors are maintained in under- ground storage. 5. MIC storage tanks are located underground: a. Tank integrity is protected by jacket and vault. 6. MIC tanks are maintained at low temperatures, minimum needed pres- sure, and are instrumented with redundant pressure, level, temperature, and temperature rate of rise alarms: a. Temperature rise is an indication of loss of refrigeration and/or reaction; b. Higher temperature increases the rate of reaction for undesirable reactions; and c. Pressure indicates venting due to contaminated MIC and/or loss of refrigeration. 7. Buffered cooling with non-reactive solvent for all MIC storage: a. Prevents contamination with reactive coolant. 8. Canned rotor pumps are used for refined MIC service: a. Prevents seal leakage to the environment even at trace levels. 9. Dedicated nitrogen supply for MIC services which can also provide a backup for instrument air. 10. Distillation condensers are placed high in the structure to avoid reflux pumps. 11. Structured process hazards analysis by HAZOP method. 12. The refined MIC has online analysis for water and major impurities: a. Provides early detection of water contamination in the event of a leak in the condenser or vent condenser. b. Both make stream and storage tanks in building are covered.

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167 APPENDIX B 13. Continually charged MIC transfer lines outside MIC unit process struc- ture are double-walled: a. Adds additional structural integrity to the transfer lines, b. Prevents small leakage from welds and flanges or from corrosion, c. Annulus is nitrogen swept and the sweep gas analyzed for organics for early detection, and d. Steam/ammonia curtain around MIC process structure to mitigate any leaks within structure. 14. Transfer from MIC underground tank to carbaryl unit is done continu - ously using double walled pipe. The MIC goes directly into the reaction loop around the continuous carbamoylation reactor. There is no MIC storage in the carbaryl unit. 15. Transfer from MIC underground tank to the aldicarb unit is also done continuously using double-walled pipe.The MIC goes directly into the batch aldicarb reactor and there is no MIC storage in the unit. Secondary measures: 1. Emergency vents to scrubber then to flare: a. MIC-bearing emergency vents have two buffers before the environment. 2. Sufficient caustic to destroy all stored MIC in the unit: a. Emergency equipment operates even in loss of site power and utilities. 3. Diesel generator provides backup power for controls and pumps needed to destroy MIC: a. Allows operation of all equipment necessary to destroy MIC, even in the event of a complete electrical power outage, utility outage; and b. Sphere nitrogen can quickly be set to supply unit instrument air header. 4. Ambient air monitors are provided to detect MIC/phosgene release: a. Provides an early warning of fast-developing releases; b. Includes sweeps on double-walled equipment and piping; and c. Covers process structure and storage building. 5. An emergency dump tank as large as the single largest MIC tank is provided: a. Provides an additional storage location in case of an emergency around the MIC storage tanks; and b. The tank is always empty, with a nitrogen blanket, is double-walled construction, and is underground. Bayer Phosgene Handling Considerations 1. Phosgene product is condensed using chilled solvent.

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168 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE 2. Small condenser accumulator is in place to provide a buffer to prevent CO reaching the MIC process. 3. All liquid phosgene vessels and piping are double walled. 4. Phosgene product is transferred to the MIC unit phosgene vaporizer by pressure to avoid pumps. 2010: Bayer planned MIC production: 11.5M lbs 2010: In response to House Energy and Commerce Committee request to investigate alternative MIC technologies, Bayer evaluated five most promising alternatives: 1. Current Bayer (UCC) process MIC(l): (phosgene + methylamine) 2. Diphenylcarbonate process MIC(g): (diphenyl carbonate + dimethyl urea based on Bayer 1971-2002 Dormagen operating data) 3. Enichem process MIC(g): (diphenylcarbonate + methylamine based on RP 1989-1990 evaluation) 4. Cyanate process MIC(g): (NaOCN + dimethyl sulfate based on Russian/ Japanese 1973-1985 patent literature) 5. DuPont process MIC(g): (methyl foramide oxidation based on SRI and RP evaluation). The carbaryl process needed to be modified to handle gaseous MIC in the last four alternatives. Evaluation Summary Diphenylcarbonate (Bayer) Pros • Investment smaller than Enichem process, • Good chemical stability of diphenylcarbonate, • Residue amount smaller than Enichem process, and • Lower storage requirements than Enichem process. Cons • ely on competition for supply of raw material (dimethylurea from BASF); R • Handling of other toxic materials (e.g., phenol); • mpact of MIC quality on product quality and hence registration likely I (new registration, if at all, requires 2-3 years); in addition, impact on aldicarb formulation highly likely because of its complexity and sensitivity to low level of impurities; • mpact on manufacturing technologies for aldicarb and carbaryl; signifi- I cant amount of process development required for adaptation (2-3 years); • arge amount of equipment required; L • iphenylcarbonate plants have been shut down more than 10 years; no in- D house know-how available any longer; learning curve expected to be steep.

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169 APPENDIX B Enichem Pros • No need for chlorine and phosgene, and • Reduction of MIC inventory. Cons • mpact of MIC quality on product quality and hence registration likely I (new registration, if at all, requires 2-3 years); in addition, impact on aldicarb formulation highly likely because of its complexity and sensitivity to low level of impurities; • mpact on manufacturing technologies for aldicarb and carbaryl: signifi- I cant amount of process development required for adaptation (2-3 years); • tilization of recycle phenol (no experience of Enichem technology at U large scale available); • ffluents quantities and qualities (residual phenol); and E • earning curve to be absorbed. L Cyanate Pros • urrently used by most of the Asian suppliers at small scale, it has C the advantage to produce MIC on demand: one batch of MIC for one carbamoylation batch. Cons • ncludes handling of other toxic materials (e.g, DMS); I • roduces large amount of waste (6 kg per kg MIC); P • or large quantities such as 4,000 Mt/year and the need to feed large F continuous units like carbaryl or methomyl, high level of MIC inventory is required; • IC can only be produced in batch, requiring a large number of large- M batch reactors; technology involves more equipment than currently at Institute, increasing safety risk; • mpact of MIC quality on product quality and hence registration likely I (new registration, if at all, requires 2-3 years); in addition, impact on aldicarb formulation highly likely because of its complexity and sensitivity to low level of impurities; • mpact on manufacturing technologies for aldicarb and carbaryl: signifi- I cant amount of process development required for adaptation (2-3 years); and • earning curve will be steep. L DuPont Pros • uPont Technology produces MIC from air oxidation of methylfor- D mamide; MIC is available diluted in N2 streams.

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170 USE AND STORAGE OF METHYL ISOCYANATE (MIC) AT BAYER CROPSCIENCE Cons • IC quality is different, impacting product quality and hence registration M (new registration, if at all, requires 2-3 years); in addition, impact on aldi - carb formulation highly likely because of its complexity and sensitivity to low level of impurities; • mpact on manufacturing technologies for aldicarb and carbaryl: signifi- I cant amount of process development required for adaptation (2-3 years); • ecause of a mix of batch and continuous process, MIC inventory needed; B • rocess streams may contain traces of toxic materials (e.g., HCN); and P • upply of raw material (methylformamide) in the hands of competitors S (BASF and DuPont). Conclusions Only DuPont process shows competitive manufacturing cost, but: • Unknown impact of by-products on product quality and registration; • Unknown impact of wastes on Institute waste handling facilities; and • Low catalyst lifetime (frequent shutdowns). Recommendation Continue with the existing MIC technology at Institute but reduce manu- facturing to two products (aldicarb and carbaryl) allowing downsizing of the MIC plant and reduction of MIC inventory by 80 percent. 2010: Bayer $25M Project MINEXT to reduce inventory by MIC 80 percent 1. Passive and active safety systems: a. Underground storage, double-walled construction; SS inner shell; b. Refrigerated MIC storage; c. Adjacent empty dump tanks; d. Scrubbers and flare system independently capable of destroying MIC in process and storage; e. Double-walled piping with annular nitrogen purge; f. Air monitoring; g. Automated control system; automated safety supervisory system, trained operators, and technical professionals; and h. Steam-ammonia curtain to mitigate phosgene or MIC leaks; i. Leak detection and repair process for extremely small leaks. 11 January 2011: Bayer announces plans to restart the East Carbamoylation Center and the new reduced MIC inventory system for aldicarb and carbaryl production, but for a period of no more than 2 years.

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171 APPENDIX B 18 March 2011: As a result of legal challenges and delays that meant missing the production window to meet demand for the 2011 growing season, Bayer announces decision not to restart aldicarb, carbaryl, or MIC production facilities and to permanently shut down the East Carbamoylation Center, ending all MIC and carbamate pesticide production at Institute.

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