Document J39vxqm8JEp34x69jNJ6eqVQr

TO: Distribution A JJH: JCL: TGG; RF (?fO ntarofflce Communication FROM: T. G. Grumbles DATE: September 11, 1984 SUBJ: VISTA COMMENTS TO THE FDA: GRAS REVOCATION OF BYPRODUCT MURIATIC ACID VISTA Enclosed is a draft of the comments we will send to FDA regarding the agency's proposal to revoke the GRAS status of all byproduct muriatic acid. Please review and return any comments or changes to me or Betsy Myer by September 19. We need to have the final comments in the mail by September 21. , c i > ---------------Thomas G. Grumbles ajo Enclosure cc Tom Huffman, Bob Klein, Mike Fortier, R. D. Gamblin Distribution: Jim Gibson, Kyle Resh, Carl Kerfoot, Betsy Myer Wayne Hilger, Nelson Borys, Bill McClain VEV-143855 A September 11, 1984 DRAFT Dockets Management Branch (HFA-305) Food and Drug Administration Room 4-62 5600 Fishers Lane Rockville, MD 20857 Dear Sirs: Vista Chemical Company (formerly Conoco Chemicals Company) is a VytWvk* vt, f*orr' major producer of byproduct -muriatic acid -in the NALKYLENE Detergent Alkylate process at its plant in Baltimore, Maryland. Vista appreciates the opportunity to comment on the FDA proposal to revoke the GRAS status of byproduct hydrochloric acid, which appeared in the Thursday, April 26, 1984 Federal Register. The FDA stated that the reason for this action is the concern for undesirable contaminants in byproduct acid. The potential for to*. conAftiAtOj specific organic contaminants in byproduct acid is highly variable, dependent on the process involved and the post treatment oV Ik otic after production. To categorically revoke GRAS status for all kyt\rtJCN>k>tt,>C J byproduct^acid regardless of general or specific contaminants ar\ aftbi Vn.oa.'y t n> oneeas nab'#. <yj>prt,oael-\ "V c> levels in the final product, is not--an appropriate manner--t-o- O-f oc-iO nriaVtOn.J address the ^onteminawt concernV^It would seem more appropriate less aabiiA^ to develop performance standards based on process design or specific contaminant levels in finished product. The Agency stated that to evaluate a specific type of byproduct acio hydrochloric'S^information was needed regarding the manufacturing VEV-143856 ^ Ike coivlaTninftM \evOs >n nito *e>*. c* kxxn Cbtmi..i; _ ., . , _ ttniCftiStttYO, m -p,Vv*>plo-re. ,noV t-opeaT Vke. q.cio Dockets Management Branch (HFA-305) Page 2 September 11, 1984 process and contaminant levels. The following is offered in order to supply that information on Vista Chemical's process. A VISTA PROCESS DESCRIPTION oilky la^CVista's NALKYLENE process is a propritary process which reacts normal paraffins with chlorine to produce chloroparaffin and then alkylated'-'the chloroparaffin with benzene in a Friedel-Crafts reaction catalyzed with aluminum chloride. Both the chlorination and alkylation reaction liberate HC1 gas which is absorbed in VvyS)8oc.V\cA>Q_ water to produce muriatic acid. The muriatic acid is then subjected to multiple purification steps before being sold. A go cVi lo re \ c. more complete description of the Hex/vnirTSTtr acid production and purification process at the Vista plant is as follows: Chlorination Step The major feedstocks to the chlorination section of the Vista NALKYLENE process are normal paraffins in the ^ecane to ^odecane range and chlorine. Chlorine is fed into a chlorination reactor where it reacts with liquid paraffin to form chloroparaffin. The chlorination step liberates gaseous HC1 by the following reaction: CH3(CH2)8CH3 + C12 H I CH -C-(CH ) -CH + HC1 Cl UEV-14385? Dockets Management Branch (HFA-305) Page 3 September 11, 1984 Off gas from the chlorination reactor is sent through a chlorine absorber where normal paraffin is used to react with any chlorine residual in the off gas. Chlorine free HC1 off gas flows from the chlorine absorber to the HC1 purification/absorption section of the process. Alkylation Step. The chloroparaffin from the chlorination section of the Vista NALKYLENE^process flows to the alkylation section and is reacted with benzene b* means ul a- Friedel-Crafts reaction using anhydrous aluminum chloride"'catalyst. The alkylation section also liberated HC1 gas by the following reaction: H CH~C~(CH,) -CH, + 3 2 7 3 cX Cl H I CH3-C-(CH2)?-CH3 + HC1 The HC1 gas from the alkylation reaction is separated from the crude alkylation reaction liquid under a slight vacuum in order to remove as much HC1 as possible. The HC1 off-gas is compressed and fed to the HC1 purification/absorption section of the Vista process. Dockets Management Branch (HFA-305) Page 4 September 11, 1984 HCl PurifIcatIon/Absorption Since the alkylation reaction is carried out in the presence of excess benzene the off-gas from the alkylation section contains benzene as well as HCl. There is also a limited quantity of benzene in the chlorination section off-gas. -In the initial step -in the HCl purification/absorption process the benzene concentration in the HCl off-gas streams is^reduced by contacting the combined chlorination/alkylation off-gas streams with Hearts chloroparaffin in an absorption tower. The chloroparaffin absorbs benzene. The HCl gas is then sent to a second absorption process where fresh water is used to absorb the HCl gas to form acid. The chloroparaf fin stream is sent to the alkylation reaction section. Fresh water is used in a two stage falling film absorption process to convert the HCl gas into muriatic acid. Final scrubbers remove any residual HCl from the inert gases which were present in the off-gas HCl prior to their venting to the atmosphere. The crude muriatic acid product is sent to the acid purification section. MuriatiT Acid Purification The crude muriatic acid from the acid absorption process contains about 1000 ppm of organic contaminants*- primarily beneetvo A Dockets Management Branch (HFA-305) Page 5 September 11, 1984 Therefore, additional purification is required to produce a final Yvy>BcW6nic muriatic acid product. Purification is accomplished in two steps VycSri-chlott it by first contacting the muriatic acid with pure paraffin feedstock in a two stage contact/separation step and then final filtration with activated carbon. A A pure paraffin stream is contacted with the -muriatic - acid and then separated from the acid in a coalescing filter/separation vessel. Two vessels are used in f series to get the optimum contact and separation. The pure paraffin stream absorbs benzene and othe^"''contaminants from the uJurtaric'^hcid. It is however, almost completely insoluble in acid itself. Therefore, the total VyiOiuich loa ic_ organic content of the-muriatic acid is reduced to about 10 ppm after this step. The final carbon filtration step reduces the total organic concentration to less than 0.1 ppm (by hexane extraction analysis) and the benzene concentration to less than 50 ppb (by photo ionization detector chromatograph). To summarize the byproduct acid produced by the process described above will contain less than 0.1 ppm of total extractable organics and less than 0.05 ppm benzene. The agency also requested data on the food catagories to which the ^ q Dq)Q aci<b(^and organic contaminants remaining in the food. Much of this information is not available to Vista as a producer. This data would best be obtained from the users ofa>wnmiMwr- acid. v\y<gecVU VEV-143860 Dockets Management Branch (HFA-305) Page 6 September 11, 1984 Iiiyaddition to the above key Items, we believe yu should also be aware^of the following potential financial impacts. A ban of by-product muriatic acid from food-grade noiyfood-grade acid among the by-product producers. This will likely cause a decrease in the non food-grade acid price and will /result in the destruction (neutralization)\of much of the excess acid. Muriatic acid neutralization is oostly and poses'^ the potential environmental problem of HC1 vapor ^release, further more, there will quite likely be regional supply sho/tages of on-purpose muriatic acid resulting in increased transportation costs to the food-grade consumers. We realize that on p^lper there willNhe no more acid being produced and things may appear to balance outy However, in reality muriatic acid inventory capabilities ark small and timing is critical. Wp believe a disruption of thia size to the market would takp years to stabilize and would result in a price difference between by-product and on-purpose\muriatic acid sign^/ficantly larger than FDA has estimated. ee. cr A VEV-l43861 A TO: Distribution nttroffic lommunicotlon FROM: T. G. Grumbles DATE: September 11, 1984 SUBJ: VISTA COMMENTS TO THE FDA: GRAS REVOCATION OF BYPRODUCT MURIATIC ACID VISTA Enclosed is a draft of the comments we will send to FDA regarding the agency's proposal to revoke the GRAS status of all byproduct' muriatic acid. Please review and return any comments or changes to me or Betsy Myer by September 19. We need to have the final comments In the mail by September 21. N, ( t/M-------------- Thomas G. Grumbles ajo Enclosure cc Tom Huffman, Bob Klein, Mike Fortier, R. D, Gamblin Distribution: Jim Gibson, Kyle Resh, Carl Kerfoot, Betsy Myer Wayne Hilger, Nelpdb Borys, Bill McClain Opuscl/# - nrcc&&rjf- ^-143865 A September 11, 1984 DRAFT Dockets Management Branch (HFA-305) Food and Drug Administration Room 4-62 5600 Fishers Lane Rockville, MD 20857 Dear Sirs: Vista Chemical Company (formerly Conoco Chemicals Company) is a major producer of byproduct muriatic acid 0the NALKYLENE 'frcjyyl Detergent Alkylate process at its plant in Baltimore, Maryland. Vista appreciates the opportunity to comment on the FDA proposal to revoke the GRAS status of byproduct hydrochloric acid, which appeared in the Thursday, April 26, 1984 Federal Register. The FDA stated that the reason for this action is the concern for undesirable contaminants in byproduct acid. The potential for specific organic contaminants in byproduct acid is highly variable, dependent on the process involved and the post treatment after production. To categorically revoke GRAS status for all byproduct acid regardless of general or specific contaminants levels in the final product, is not an appropriate manner to address the contaminant concern. It would seem more appropriate to develop performance standards based on process design or specific contaminant levels in finished product. The Agency stated that to evaluate a specific type of byproduct hydrochloric information was needed regarding the manufacturing V0)-143866 Dockets Management Branch (HFA-305) Page 2 September 11, 1984 process and contaminant levels. The following is offered in order to supply that information on Vista Chemical's process. VISTA PROCESS DESCRIPTION Vista's NALKYLENE process is a propritary process which reacts normal paraffins with chlorine to produce chloroparaffin and then alkylated^the chloroparaf fin^wityj^enzeri^ in a Friedel-Crafts reaction catalyzed with aluminum chloride. Both the chlorination and alkylation reaction liberate HC1 gas which is absorbed in water to produce muriatic acid. The muriatic acid is then subjected to multiple purification steps before being sold. A more complete description of the HCl/muriatic acid production and purification process at the Vista plant is as follows: Chlorination Step The major feedstocks to the chlorination section of the Vista NALKYLENE process are normal paraffins in the Decane to Dodecane range and chlorine. Chlorine is fed into a chlorination reactor where it reacts with liquid paraffin to form chloroparaffin. The chlorination step liberates gaseous HC1 by the following reaction: A CH3(CH2)8CH3 + C12 CH,,-<!-< CH -C-(CH ) -CH + HC1 Cl VEV-14384? Dockets Management Branch (HFA-305) Page 3 September 11, 1984 Off gas from the chlorination reactor is sent through a chlorine absorber where normal paraffin is used to react with any chlorine residual in the off gas. Chlorine free HC1 off gas flows from the chlorine absorber to the HC1 purification/absorption section of the process. Alkylation Step. The chloroparaffin from the chlorination section of the Vista NALKYLENE process flows to the alkylation section and is reacted with benzene by uieaim uf wt Friedel-Crafts reaction anhydrous aluminum chloride^catalyst. The alkylation section also liberated HC1 gas by the following reaction: H ch3-^-(ch2)?-ch3 + (} --> Cl H + HC1 The HC1 gas from the alkylation reaction is separated from the crude alkylation reaction liquid under a slight vacuum in order to remove as much HCl as possible. The HC1 off-gas is compressed and fed to the HCl purification/absorption section of the Vista process. kJac j^Cl( (yo fU 0ML- C,0 (j'f ll ] A Dockets Management Branch (HFA-305) Page 4 September 11, 1984 HC1 Purification/Absorption Since the alkylation reaction is carried out in the presence of excess benzene the off-gas from the alkylation section contains benzene as well as HC1. There is also a limited quantity of Duftnc* benzene in the chlorination section off-gas. .In'the initial step ^n^ the HC1 purification/absorption process the benzene concentration in the HC1 off-gas streams is reduced by contacting the combined chlorination/alkylation off-gas streams with / chloroparaffin in an absorption tower. The chloroparaffin ahoorb-obenzene. The HC1 gas is then sent to a second absorption process where fresh water is used to absorb the HC1 gas to form muriatic acid. The chloroparaf fin stream is sent to the alkylation reaction section. Fresh water is used in a two stage falling film absorption process to convert the HC1 gas into muriatic acid. Final scrubbers remove any residual HC1 from the inert gases which were present in the off-gas HC1 prior to their venting to the atmosphere. The crude muriatic acid product is sent to the acid purification section. Muriatic Acid Purification Cj -+U *) CAa/J f4usl+<a.^- The crude muriatic acid from the acid absorption process contains about 1000 ppm of organic contaminants - primarily benzene. A VEV-143869 Dockets Management Branch (HFA-305) Page 5 September 11, 1984 Therefore, additional purification is required to produce a final muriatic acid product. Purification is accomplished in two steps by first contacting the muriatic acid with pure paraffin feedstock in a two stage contact/separation step and then final filtration with activated carbon. A pure paraffin stream is contacted with the muriatic acid and then separated from the acid in a coalescing filter/separation vessel. Two vessels are used in series to get the optimum contact and separation. The pure paraffin stream absorbs benzene ? and other^ contaminants from the muriatic acid. It is however, almost completely insoluble in acid itself. Therefore, the total organic content of the muriatic acid is reduced to about 10 ppm after this step. The final carbon filtration step reduces the total organic concentration to less than 0.1 ppm (by hexane extraction analysis) and the benzene concentration to less than 50 ppb (by photo ionization detector chromatograph). To summarize the byproduct acid produced by the process described above will contain less than 0.1 ppm of total extractable organics and less than 0.05 ppm benzene. O-Sl-aCQ &aWC'<2--''' The agenpy also requested data on the food catagories to which the acid, and organic contaminants remaining in the food. Much of this information is not available to Vista as a producer. This data would best be obtained from the users of hydrochloric acid. Dockets Management Branch (HFA-305) Page 6 September 11, 1984 In addition to the above key items, we believe you should also be aware of the following potential financial impacts, j A ban of by-product muriatic acid from food-grade non food-grade acid among the by-product producers. ^This will likely cause a decrease in the non food-grade acid price and will result in the destruction (neutralization) of much of the excess acid. Muriatic acid neutralization fs costly and poses the potential environmental problem of HC1 vapor release. Further more, there will quite likely be regional supply shortages of on-purpose muriatic acid resulting in increased transportation costs to the food-grade consumers. We realize that on paper there will be no more acid being produced and things may appear to balance out. However, in reality muriatic acid inventory capabilities are small and timing is critical. We believe a disruption of this size to the market would take years to stabilize and would result in a price difference between by-product and on-purpose muriatic acid significantly larger than FDA has estimated. A n-tj- 1 143871