Document 7Om0RG1bQDxO0RJjLVKrzwVq8

I Chronology Complaint filed Exchanged Interrogatories Draft settlement presented Justice draft Discussion ' Counterproposals Handshake Final February 1981 August August November January 1982 February, April June September (?) Problems Add equipment - dropped. Stipulated penalties for NESHAPS - dropped. Penalties for violation of decree - reduced, classified. Possible Sec. 120 complaint - avoided. Training - required for all, new and old. - Competency test for new. Causalty - lost. Final Version Training, procedures (90/24, 9 months for Maintenance). Logging of status, response Penalties, cash and stipulated. Time, 2 years operation or 3 years after restart. New equipment to be covered also. AP00018778 [^cp^^T^AoducZ^] ( /';.VC Air Products and Chemicals. Inc. Box 538 Allentown. PA 18105 {215)461-4911 24 September 1982 Document Control Officer TS-793, OPTS, Room E-401 401 M Street, S. W. Washington, DC 20460 Gentlemen: Re: Docket OPTS-50033 Air Products and Chemicals, Inc., submits herewith Is comments on the proposal to amend 40CFR723.250 to provide a PMN exemption for certain polymers, as noticed at 47FR33924, 4 August 1982. We presume that these comments are required In triplicate, as were those of the companion Notice at 47FR33896, even though this Notice does not state that fact, and enclose three copies. We oppose many of the requirements of this proposal, and believe that several other parts need clarification. We agree with the concept of reducing the burden on the public and the Agency by providing exemptions to the current unofficial but established PMN procedures. We agree that many of the exemptions contained In this proposal are useful to that end, and should be approved. We do not agree with many of the proposed exclusions to these exemptions, for the reasons discussed below. Air Products Is a manufacturer of polyvinyl chloride (PVC) and polyvinyl alcohol (PVOH) both of which would be denied exemptions under this proposal, despite the fact that both have been used safely for many years In food, drug, cosmetic, and medical applications. Therefore we conclude that the criteria for exclusions from the exemptions have been formulated Improperly, and we present our reasons below for that conclusion. We have commented on the companion proposal for site-limited and low-volume exemptions, Docket OPTS-50032A, 47FR33896. Many of the general comments there are applicable here also, and we ask that those comments be Incorporated by reference In this docket. We are members of the Chemical Manufacturing Association, and have reviewed a draft of their comments on this matter. We support their comments generally. In particular, however, we believe that their proposal for an expedited PMN rather than exclusion from the exemption is a worthwhile suggestion and we urge your careful consideration. If the Agency Is unwilling to remove such demonstrably safe classes of polymers such as the PVC's and PV0H`s from the exclusion list, it should at least allow them an accelerated PMN. However, we see no reason why those classes should be singled out for any special treatment. APOOb18779 Docket OPTS-50033 -2- 24 September 1982 We appreciate the opportunity to comment on this proposal, and will be happy to discuss any of these points further If that is discussed. Sincerely, AIR PRODUCTS AND CHEMICALS, INC. JTB/cay Attachment j. ' ' " - /_'.{ John T. Barr Regulatory Response bcc: A. J. Diglio J. Dubeck - Keller and Heckman F. Licktenberg - SPI AP00018780 Comments On Proposed PMN Exemption for Certain Polymers Docket DPTS-50033 47FR33924 4 August 1982 by Air Products and Chemicals, Inc. 30 September 1982 APOOOI8781 Table of Contents I. Introduction II. Polyvinyl Chloride (PVC) A. Current Regulatory Status 1. Food and Orug Administration 2. Occupational Safety and Health Administration 3. Environmental Protection Agency B. Eligibility for Exemption 1. Molecular Weight 2. Polydlsperslty III. Polyvinyl Alcohol (PVOH) A. Current Regulatory Status B. Eligibility for Exemption 1. Polydlsperslvlty 2. Blodegradabllity IV. Economic Impact A. Cost of Compliance B. Benefits of Compliance C. Saving of Agency Resources V. Technical Comments A. Polydlsperlsty (PD) B. Exemption Wording C. Scope of the Proposal D. Molecular Weight Classes E. Extraordinary Powers F. Functional Groups 1 1 2 2 2 3 4 4 5 5 6 7 7 8 8 8 9 10 11 11 11 11 12 12 13 APbbbi8782 Table of Contents (continued) G. Carbon Content VI. Risk Assessment A. Vinyl Chloride 1. Incorrect Potency Values 2. Incorrect Residual Monomer Levels 8. Water Soluble Polymers C. Polymers Designed to Degrade VII. Improper Exclusionary Action VIII. Summary Page 13 14 14 14 15 15 16 17 17 APOOO18783 I. Introduction We understand, of course, that this rulemaking will not affect current Inventoried products directly. It will have, however, significant Indirect effects. There will be a stigma attached to any product class which is excluded by this proposal, because of the suspicion that the exclusion rule Implies a potential for some hazard. There also will be an Important effect on new product development, especially on the flexibility of producers to make adjustments In the composition of a product to meet changing needs of a customer or to adapt to new uses. This burden will fall particularly hard on small manufacturers, or on small volume specialty producers where the resources may not be avail able to meet the complex technical demands for exemption which are proposed here. It appears that this proposal Is not Intended to cover the large class of high molecular weight polymers which are termed "structural". There Is no reference In the Notice to the several communications which the Society of the Plastics Industry, Inc. (SPI) has had with the Agency, and structural polymers are not discussed. The thrust of all the discus sions seems to be toward low molecular weight materials. Further, the worker exposure assessment document by Mitre Corp. (ref. 50 of the Notice) states on p. 3 that the substances studied "are not the structural polymers as described by the Society of the Plastic Industries, Inc.", and references the SPI position paper of August, 1981 describing Its proposal to exclude structural polymers from the Inventory, as do the European rules. Had the Notice been clear about the relationship of structural polymers to this rulemaking, It may have avoided much of the concerns that the Notice has caused. We cannot proceed on assumptions, however, and our comments speak to the Notice as It appeared, without any statement distinguishing structural polymers. In addition, much of the effort seems misdirected toward monomers which already are on the Inventory, and thus are not subject to PMN rules. We will discuss first the proposal as It applies to the two classes of polymers of particular Interest to us, and then present general comments on other aspects of the proposal. II. Polyvinyl Chloride (PVC) Except for its coverage by the proposed exclusion of 40CFR723.250(d)(5), PVC (homopolymers and copolymers) meets all of the criteria for the exemptions of this proposal. The Preamble states at p. 33928, In sec. 3B5 that the only reason for this exclusion is concern for residual monomers. Vinyl chloride (VC) Is named specifically there, although misspelled. On the face of It the exclusion Is Incorrect, because not APOOO18784 all chlorine - containing polymers are made from vinyl chloride. Other major families of chloride - containing polymers may be made from chloroprene, vlnylidene chloride, chlorofluorooleflns, and so on. Vlnylldene chloride was reported by the National Toxicology Program (Fiscal year 1982 Annual Plan, page 87) not to be carcinogenic In rats or mice In report NTP-80-082, TR228, NIH publication 82-1784. Chloroprene Is stated In that same report not to be mutagenic In the Ames test (p. 52, Item 34 of Table 2). Thus It is improper to state a concern for the toxicity of all chlorinated polymers because some may be prepared from vinyl chloride, which Is toxic, when there Is not evidence of similar toxicity In other monomers also covered. A regulatory decision based on such a position would be an arbitrary misuse of regulatory discretion. However, directing attention to only PVC and Its principal monomer, the Agency does not seem to be aware of the current regulatory status and safe use of these materials. A. Current Regulatory Status 1. Food and Drug Administration PVC currently Is approved and/or has prior sanction for use as food contact components, components In packaging materials, and In paper (21CFR175, 178). The FDA proposed to withdraw the prior sanction for food contact for rigid forms In 1975 because of concerns for residual monomer, but announced this year that It will withdraw that proposal. See the "Second Annual Report on Carcinogens11, National Toxicology Program, Public Health Service, December, 1981 (Issued May, 1982), page 240. The 1975 notice stated specifically that the status of plasticized PVC was not to be changed. In plasticized form the product is used In blood bags, transfusion and drainage tubing, food conveyors, and many other critical applications. Thus, PVC Is not Inherently harmful, If processed properly. This point Is supported by the Mitre Report (ref. 50) referred to above, which states each time applications of PVC are discussed that consumer and environmental exposures are negli gible. See, for example, pages 88, 97 and 107 of that document. The vinyl chloride emulsion copolymers (EVC1) are approved for use by FDA under 21CFR175.300 and 176.170. 2. Occupational Safety and Health Administration The Notice states that one of its concerns is exposure to residual monomer during processing. OSHA established (29FR1910.1017) a standard for occupational exposure to VC which sets an action level of 0.5 ppm (8-hr. TWA) below which the standard does not apply. This action level effectively exempted processing and fabrication plants from the OSHA standard because the residual level of monomer In PVC is so low that the action level is not exceeded. 2 AP00018785 Thus, polymers of vinyl chloride can be processed safely, In accordance with the very rigid exposure standards which are Imposed on them. This position also Is supported by the Mitre report, which states on p. 4: There Is normally little potential for workplace expo sure to high molecular weight thermoplastic resins used for Injection molding and extrusion. Environmental Protection Agency This Agency has a standard (40CFR61.60) for environmental release of VC. This includes among other provisions, that suspension polymers, which use over 85% of the VC consumed In this country, must be stripped to less than 400 ppm residual monomer on a dry basis before contact with the atmosphere (there Is an alternative of controlling dryer off-gases, but all U.S. producers have chosen the stripping method for compli ance.) Voluntary industry agreement have reduced this to 10 ppm In the finished polymer for the majority of products which go into consumer goods, which provides further protection for fabrication employees, consumers, and the environment. See EPA 450/3-82-003 for further details on this point. This Agency recently approved a test marketing exemption for a vinyl chloride-ethylene copolymer. See 47FR38632, 1 September 1982, TM-82-44. This Notice states that the Agency has estab lished that this approval will not present an unreasonable risk of Injury to health or to the environment because of low health and ecological concern for this polymer. The EPA and FDA have a memorandum of understanding signed 12 June 1979 by the Administrator which assigned to the Agency the responsibility of controlling direct and indirect additives to drinking water, which would Include any leechate from pipe. Waste disposal is regulated by the RCRA rules, and other spills and releases are covered by the CERCLA regulations. Under these, VC and PVC are literally covered from the cradle to the grave by several stringent and all-encomposlng standards. Thus, the environment, the worker, and the consumer are protected from adventitious VC by existing regulations. Adding to this safety Is the fact that VC migrates slowly, If at all, from finished forms under use conditions. Emissions, if they occur, do so only under heat processing. 0SHA regulations cover this step. Therefore, we seen no reason for EPA to be concerned about potential exposure to the environment or persons from exist ing PVC use. Any new VC-contalnlng products are covered by 3 AP00018786 the existing OSHA-EPA rules, and cannot be produced outside of their control. Thus, there is no reason for concern over possible future exposure from new products. In addition to providing considerable assurance that no harm comes from the manufacturer use of PVC, the facts recited above lead to the conclusion that the Agency may not regulate vinyl chloride polymers under TSCA. Section 9 of the TSC Act requires that efforts be made to regulate potential hazards under existing statutes and regulations before TSCA Is Invoked. Regulation of PVC because of concern of exposure to Its residual monomer under this proposal would be a duplication of regulation, which Is forbidden by Sec. 9. Further, because VC Is on the Inventory, Its presence in polymers would be defined as a mixture, which Is not subject to TSCA rules. See the discussion on p. VI-12 of support document 54 of this Notice, for a further discussion of this point. There It Is stated that monomers are not subject to 5(h)(4) regulation. This proposal, therefore, appears to be an effort to bypass Sec. 5 of the TSC Act, and to produce an unauthorized SNUR requirement for Inventoried monomers. These are strict procedures delineated for SNUR actions, and this proposal does not conform to those requirements. If the Agency has concern for the hazards of certain monomers, it has available the Sec. 4 Test Rule procedure, and should not attempt to regulate such materials on suppositions outside the statutory mandate. Therefore, the Agency may not regulate PVC, or other polymers, for the reasons stated In Sec. Ill B 5 of the preamble unless or until it has determined that the existing regulations or the other remedies available to it under the statutes cannot and will not control the potential hazard. We do not believe that such a determination can be supported by fact. B. Eligibility for Exemption The proposal specifies several criteria for exemption. Each of these Is discussed below with reference to PVC. 1. Molecular weight Exemption Is offered to polymers with number average molecular weights of greater than 20,000. The commercial polymers and copolymers classed as conventional PVC have weights of 65,000 120,000. Those below this range are too brittle for satisfac tory service. Those above this range have very difficult processlblllty, and are not useful. Other less well-known copolymers of VC, termed 11EVC1 **, are made utilizing ethylene, for example, as a comonomer. These are prepared In emulsion form, and have molecular weights in the range of 50,000-90,000. 4 APOOOI8787 2. Polydlsperslty Conventional PVC has a polydlsperslty of about 2, and the emulsion copolymers have a value of about the same range. This Is well within the allowable values of Table 2 of the proposal. There Is essentially no polymer with a weight below 1,000 present In the commercial products. Therefore polymers and copolymers of VC which have commercial utility meet all of the requirements of the proposal paragraphs (e) and (f), and are excluded only because of chlorine content. We have shown above that the potential for vinyl chloride exposure is regulated strictly by existing regulations, and that current products are approved for a wide range of consumer and medical applications, and are being used safely and satisfactorily in those applications. We see no reason why new products containing VC would not be equally safe, as they would be covered by the same regulations. The OSHA and EPA regulations apply to any place where vinyl chloride Is present or is used In polymers to any extent whatsoever. We therefore request that the Agency remove the exclusion from the proposed exemptions as It applies to polymers and copolymers of vinyl chloride. We fully expect most types of PVC will be exempt from all Inventory requirements under any forthcoming structural polymer rulemaking. Nevertheless, we also believe that It Is proper for the Agency to Include new variants of PVC under the exemption of this rulemaking, so as to avoid unnecessary Inhibition of Innovation and Impact on foreign trade which the present PMN procedures Impose (see 47FR33910, 33913, and 33917-18). III. Polyvinyl Alcohol (PVOH) Polyvinyl alcohol Is the product of hydrolysis of polyvinyl acetate (PVAC), a homopolymer of vinyl acetate (VAC). All or most of the pendant acetate groups are removed by hydrolysis or saponification of PVAC to give a material containing only carbon, hydrogen, and oxygen, with the structure - [CH^DKOH)]^ It is a stable, nontoxic polymer and Is water soluble to various degrees, depending on the completeness of removal of the acetate moieties. Therein lies the problem. This causes PVOH to fall under the proposed exclusion of (d)(1) - water soluble polymer. Also, unfortunately for this proposal but fortunately for the environment. It Is biodegradable, and thus falls under (d)(7) also. PVOH was not necessarily designed to have these properties, It just turned out that way. Extensive use of PVOH has resulted from Its water solubility, but It also has applications In films, coatings, fibers, and molded products. We do not understand the Agency reasoning as to why these properties are deemed to be harmful, and as Is discussed below, we believe that PVOH should be removed from the exclusion because of Its lack of potential for harm to the environment. 5 AP00018788 A. Current Regulatory Status PVOH has approval and/or prior sanction for use as a food contact surface component, an adhesive component for packaging materials, and a color additive diluent under 21CFR175-178 and 181. It Is listed In the U.S. Pharmacoplea as a viscosity - Increasing agent and as a pharmaceutic necessity for opthalmlc solutions. Both It and Its precursor PVAC have a long history of safe use In many food and consumer applications. There Is no residual monomer In the final product. The production process Includes an extractive distillation which recycles the unreacted vinyl acetate. Even If It were present, VAC has a low toxicity. Its hydrolysis products are natural components of the human metabolic process. See DHEW-NIOSH Pub. No. 78-205, 1978 "Criteria for a recommended standard - workplace exposure to vinyl acetate" for a summary of the toxicity of vinyl acetate. The precursor polymer, PVAC, Is also nontoxic, and Is used as a base for chewing gum and many other FDA-approved applications. Thus, even If there were any residual monomer or precursor polymer, there would be no toxic hazards from their presence. The lack of toxicity of PVOH which permits these applications Is well established. Earlier data have been reviewed In "Klrk-Othmer Encyclopedia of Chemical Technology", volume 21, 2nd edition, p. 359 (Interscience, 1970), and the "Encyclopedia of Polymer Science and Technology11, volume 14 (Interscience, 1971). In' summary, these reviews referred to above show that oral adminis tration of PVOH to rodents causes no chronic effects, and there are acute effects only at doses over 2g/Kg/day. See: Platzer, Mod. Plastics 28 (7) 95 (1951); Inskip and Peterson, Mod. Packaging 30 (1) 137 (1957); Lefaux, Chemie und Toxlkoloqle der Kunstoffe. Virlag, Mainz, 1966, pps. 292-295; Babev, Azerb. Med. Zh.. 56T10) 18 (1979). PVOH Is not metabolized by humans. Very low molecular weight substances, If present, pass through the liver and kidney to the urine; the higher polymers remain in the feces ("Elvanol", duPont, Wilmington). Efforts were made to use PVOH as a blood extender, but It was found that at the higher concentrations where It would be most useful, It caused coagulation of the blood, so this use is not commercial. See: Kalner, "Polyvlnylalkohol", Enke, Stuttgart, 1949; Danlshevskl, et al., "Toksikol Vysokomol Mater Khlm", Inst. Pollm. Plast. Mass, pps. 94-105 (1966); Grigoryan, et al., Z. Kh. Partev. (Tlflls) (1967) 10-11, 113-116; Hueper, et al., J. Pharmacol. Exptl. Therap., 70 201 (1940). Otherwise, Injection of solutions caused no toxic effect. See: Hueper and Kalner, op. clt. and Zaeva, et al., Tokoikol. Novvkh. Prom.. 5 136 (1963); Well, 0. Pharm. Belq. 18 (45) 445 (1963). -- 6 APOOOI8789 Unpublished results obtained by Air Products at Biosearch, Inc. of Philadelphia, Pa. In 1978 and 1979 show that neither the powder nor aqueous solutions of PVOH are primary Irritants to rabbit eyes or skin, whole or abraded. Rats were exposed to as much as 24 rag/m^ of 3-5 micron PVOH dust without effect, and gross pathological examination 14 days later "revealed nothing remarkable11. Thermal decomposition of PVOH at 200C and up yields primarily water and char with small quantities (about IX) of alcohols, ketones, and aldehydes (Finch, "Polyvinyl Alcohol", Wiley and Sons, New York, 1973). RETECS classifies PVOH as an animal carcinogen, and cites Vol. 19 of the IARC series as the reference. That volume discusses only various subcutaneous Implantation tests. These were found to produce local tumors If the correct size particles were used. Powders did not give this effect, platelets of mm size range did. This Is a well-known effect which almost any solid substance will produce [Zlche and Gulllno, Can. Res.. 41 5060 (1981)]. It Is the result of the universal foreign body reaction, and Is not accepted as a carcinogenic response. See, e.g.. Brand "Foreign Body Induced Sarcomas" In Becker (ed.) "Cancer, a Comprehensive Treatise", Vol. 1, pps. 485-511, Plenum Pub., New York, 1975. OSHA excludes Implantation site tumors of this type from classification as an Indicator of a carcinogen. See: 29CFR1990.144 (b)(11), 45FR5287. The cited IARC volume states (p. 359) that they draw no conclusion as to carcinogenicity from these data. Thus, the classification by RETECS Is Improper, and Is not accepted by the scientific community. It makes the same error for PVC, polyethylene, and many other materials accepted as innocuous. Further, PVOH and these other materials are used successfully as surgical implants (Kirk-Othner and IARC, loc. cits.) In both humans and animals. We therefore conclude that PVOH Is not a "carcinogen" within the general meaning of the term, or as It Is used here by the Agency. B. Eligibility for Exemption 1. Polydlspersivlty The attached table shows the molecular weights and calculated PD values for our commercial grades of PVOH. The Mn values can be seen to range from about 28,000 to about 110,000. The PD values are generally In the 115-210 range. This value Indicates a somewhat narrow molecular weight distribution, and allows essentially no material below 1,000 to be present. Therefore, PVOH Is acceptable for exemption under this proposal so far as PD values are concerned. 7 APOOOI8790 Table I PVOH Molecular Weights by GPC/LALLS Sampl e V205 V523 V540 VI07 V325 V350 WS42 # 04080706 09110327 701090230 04080706 07090887 04100680 02110190 DPN 24,800 59,800 109,400 22,300 53,700 98,100 - DPW 49,600 119,600 218,800 44,600 107,400 196,200 - 28,200 67,800 110,300 27,800 57,800 79,800 42,800 Hw. 41,100 130,300 181,900 43,200 105,800 152,900 90,400 _* hm V"h 42,800 1.46 138,000 1.92 174,900 1.65 35,100 1.55 107,000 1.83 131,400 1 .92 99,500 2.11 DPN Number-average MW from degree of polymerization DPW * Weight-average MW from degree of polymerization Rjj Number-average MW from GPC/LALLS * Weight-average MW from GPC/LALLS My* Weight-average MW from static LALLS (KMX-6) AP00018791 2. Blodegradablllty For many years PVOH was thought to be nonblodegradable, and achieved some utilization as a replacement for starch as a textile sizer because of this (Finch, loc. cit.). In fact, It Is fairly easily degraded after some acclimatization of the flora, and degrades completely to carbon dioxide and water. The attached reports from our laboratory give the details of both laboratory and large-scale tests which Illus trate this property. Attachment I, Casey and Manley "PVOH Degradation by Oxygen-Activated Sludge", Third International Degradation Symposium, August 1975. Attachment II, April 1, 1982 letter from J. P. Casey to a customer. We believe blodegradablllty to be an asset, and not a liability as this proposal claims. This Is especially true when the degradation goes to completion, as is shown in the attached data. No harm can come to the environment from either the material Itself or Its degradation products. The degradation process Is seen to be nontoxic to ordinary populations of bacteria In sewage effluent, and thus does not Interfere with other biological processes, or pose a threat to the environment. Our conclusion Is that PVOH Is an Innocent product which happens to have fallen Into the net spread by the Agency In its concerns for possible new hazards. We believe that It should not be excluded from the potential exemptions. It should be noted that if starch were to be discovered after this rule became effective, It would be excluded for exactly the same reasons as PVOH - water solubility and blodegradablllty. (Sugars, of course, fall into a third excluded group - low molecular weight.) One way out of this untenable situation would be to grant blanket exemp tion to all polymers containing only the atoms carbon, hydrogen, and oxygen. Falling that, known nontoxic functional groups, such as the allphatlc-OH group, could be made another prerequisite, as It is In (d)(6)(H) For functional groups as a class. We urge the Agency to consider seriously this approach so that it Is not put in the anomalous position of excluding recognized pharmaceuticals such as PVOH or major foodstuff such as starch from the exemption. Economic Impact We believe that the economic analysis present in the preamble at Sec. IV B Is defective on several points. These are discussed below. A. Cost of Compliance The economic Impact of this proposal Is based largely on an unrealIstlcly low estimate for performing the tests necessary to provide the Information needed for the exemption notice. For example, a cost of about $400 Is used for a chromatographic analysis to measure molecular weight distribution. That figure can be correct only for repetitive analyses of a well-characterized material in a laboratory equipped to perform such analyses routinely. However, 8 APOOO18792 this proposal applies to new substances. Because they are new substances, It will be necessary first to calibrate the apparatus for this new polymer. This is a research project of some magnitude, and requires extensive time, technical resources, and of course, money. For example, until very recently the standard method to determine the molecular weight of PVOH was to reacetylate It to PVAC so that It was soluble In the conventional organic solvents, and to determine the molecular weight by GPC. This was a satisfactory procedure, but gave only an Indirect value for partly hydrolyzed products and required correction for the estimated degree of hydrolysis. After a three-year search for a more suitable method, we have now concentrated our efforts on a new direct procedure using low angle laser light scattering. Development of this procedure, after we had settled on an analytical method, required about 4 more months of labor over the period of nearly a year. Direct charges for just the last phase of this project were $22,000, plus a small amount of effort allocated to another project, this does not Include equipment costs, or general administrative overheads. After full development of this method our repetitive costs will be low. However, when we produce a minor variation of our standard polymers, at least a portion of the validation and calibration work must be repeated to assure ourselves that the procedure Is appropriate. A major variant or a new polymer will require about as much effort as did the above exercise. Thus, we cannot agree that $400 is a reasonable figure for a P0 determination on a new product. It Is for this reason of cost that such determinations are not used routinely as quality control measurements, but are reserved for research projects. This burden will fall most heavily on a small manufacturer who must either provide such equipment, costing $50,000 and up, and then establish the necessary skills and calibration, or depend on outside laboratories, where the costs and delays are likely to be large. Similar comments apply to the required fractionation effort to determine the low-molecular weight content. This is still largely an art, not a well-developed science, and no generic procedures can be established for this step. Each study becomes a separate research project, consuming much time, and requiring considerable expenditures. Because of errors such as these In the cost analysis, the economic analysis Is Incorrect. B. Benefits of Compliance We see little Incentive for a producer of a new polymer to use the exemption procedure. The largest Incentive seems to be a postulated saving of 90 days or so In the ability to proceed with production. 9 AP00018793 This Is a phantom Incentive. At the time the manufacturer has the commercial and scientific data at hand to proceed with scale-up, there Is the option to submit either a PMN or an exemption request. The PMN can be prepared and submitted In a few days. The exemption data development can take days or weeks to obtain, and results in data useful only to one specific variant of the product. Thus the time saved will be less than 90 days by some unknown factor, the cost will be greater, and the resulting permit will be far less flexible as to further production variations than would a PMN approval. Actually, the Incentive is not to avoid a 90-day PMN examination, for there are other alternatives available to a producer. These Include the THE, for which there Is a 45-day period, the low volume and site-limited exemptions of proposed 40CFR723.10 (Docket 50Q32A) which requires simply a notice for materials of this molecular weight, or the Research and Development route, all of which allow production of specified amounts with lesser waiting periods than for a PMN. A potential producer will evaluate each of these alter nates before choosing the more laborious route of this proposal. In addition, the excessive record keeping that Is required under an exemption as compared to that for a normal PMN procedure Is further disincentive for choosing this route. C. Saving of Agency Resources The discussion above leads us to believe that only a small portion. If any at all, of new polymers will be processed through the exemp tion route, and any predicted reduction In Agency work load will thereby be diminished. In addition, we understand that the Agency now completes most, If not all, of the polymer-related PMN`s In about 14 days. This Is confirmed by a comparison of the submission and approval dates for polymer PMN's and TME`s appearing In recent Issues of the Federal Register. Therefore, there will be no significant reduction In burden achieved by the minl-PMN process proposed here. There could be an Increase If more data must be evaluated. Perhaps most significant of all, these exemptions are valid only for some vague and undefined "conditions of the exemption", and the full PMN process must be employed If these "conditions" are exceeded. See the discussion of preamble Sec. Ill B. Therefore we fall completely to understand how a claim for benefit can be developed from failure to place these new products on the Inven tory. It will be necessary to go through the PMN process anyway if the product is a commercial success. (Of course, the SPI proposal to remove structural polymer altogether from the Inventory would result In a large savings of resources by both the Agency and Industry.) 10 APOOO18794 Further, our expectation Is that In many cases the producer will elect to utilize both routes simultaneously as assurance of a positive response. This will only serve to Increase the burden of the Agency. Therefore, for these reasons, the economic impact Is Invalid. We believe that this proposal, In those Instances where it may be used, will not provide a significant burden reduction to Industry or the Agency. Technical Comments There are several technical errors in the proposal which are worthy of comment. A. Polydlsperslty (PD) This value Is, as stated, one method of measuring the range of molecular weight of a polymeric mixture. Because of this, PD values of 1.0, or any value near that figure, are Impossible In mixtures of polymer species. That value Is possessed by only discrete chemical substances, not polymeric mixtures. See p. V-19 of support document 54 of this proposal for further discussion of this point. Table 2 of the Notice Is the result of the expansion of an arbitrary mathematical expression designed apparently to give assurance that amount of low molecular weight material though to be undesirable are not present. It bears no relationship to real-life situations, and should be abandoned for a more realistic parameter. If fractionation Is to be required, then there Is no need for this criterion. B. Exemption Wording The content of proposed sec. 723.250 (e) (3), the PD exemption criteria, suggests that It applies only to polymers in the range of 3,000 to 20,000. If this Is correct, ft should be stated clearly. However, as discussed above, we doubt the scientific validity of the basis for this exemption. Note that there appears to be a typographical error in the values of PD In Table 2 for the molecular weight range of 4,000 to 4,999. We also are very doubtful of the ability of molecular weight deter mination to produce results accurate to four significant figures, as Is Implied by Table 2 of the Notice. Our experience is that can be determined to about 5-13%, and MW to 3-7%. Thus there can be as much as 20% variability In PD as calculated from these data. This experience Is supported by statements In cited reference 51 of this proposal at pages 53 and 71, and In docuemnt 54 at p. V-6. C. Scope of the Proposal Many of the problems with the' clarity and applicability of the proposal stem from the attempt by the Agency to compress several petitions Into one generic rule. This is In fact a proposal covering 11 APOOO18795 polyesters and a variety of other low molecular weight products, most of which seem to be prepolymers and Intermediates, not true polymeric products suitable for final processing or use. This would have been much clearer and effective If the proposal had been broken down Into discrete classes of polymers based on applica tion and structure/functionality, and not lumped together as they are. We recommend that the Agency rethink the organization of the proposal In order to make It more effective. D. Molecular Weight Classes Many structural polymers may have molecular weight as low as 6-8,000. The Nylons and low molecular weight polyethylenes are majors example of these. The physical state Is a function of structure, size, and the Interaction of polarizable segments. The 20,000 figure Is not a parameter that Is relatable to any basic principle. Empirical data suggest that a 5-6,000 cut-off Is a more realistic division between materials that may or may not be able to enter the biosphere as other than Inert substances. This is supported by the discussion at p. 33 at reference of Document 50, which describes polymers with molecular weights over 5,000 as physiologically Inert. Whether or not the substance Is "liquid*1 Is not relevant. A material of molecular weight above 5,000 will not be a liquid In the ordinary sense. It may have some poor fluid properties, especially if heated, but certainly Is not a conventional liquid, nor will It be water soluble unless a high ratio of polarizable groups Is present. Petroleum waxes, such as those used In home canning, have molecular weights of only 400-700 (Klrk-Othmer loc. clt., Vol. 15, p. 93), and these have the least Intermolecular Interaction of any substance (there are no polar functional groups present) yet they are solids. Those with polar groups will be even less fluid. Therefore we recommend 5,000, and not 20,000 as demarcation between low and high polymers. E. Extraordinary Powers The Agency grants to the Director of 0TS extraordinary discretionary powers In proposal sec. 250 (n). Even after going to all of the extra effort to attempt to comply with the requirements of this proposal the producer has no assurance that the Director may not, for whatever reason, determine that "the manufacturer of the new chemical substance does not meet all of the terms of this section ---There is no appeal, no hearing process, nor any other proce dure for limiting the potential abuse of discretion under this section. We believe that this section Is beyond the scope of the Act and the Administrative Procedures Act, and must be deleted or modified substantially before It Is acceptable. Producers who enter Into contracts as the result of an Agency action are subject to serious consequences If the Agency later rejects that action arbitrarily. 12 AP00018796 F. Functional Groups The proposal at .250 (d)(3) and (b) that functional groups be limited to a ratio of 1 In 10,000 units Is overly conservative and Is Inconsistent with current policy that allows a 2% by weight Incorporation of a new monomer without a requirement of a PMN. Further, it is essentially Impossible to meet In the class of polymers for which this proposal appears to be Intended. A polymer of 5,000 molecular weight made from a monomer of 100 Daltons has only 50 units. Thus, this proposal would allow a functional group only once every 200 polymer molecules. This Is an effective exclu sion of functional groups, for they must be present In essentially all molecules to be useful. It appears that this selection of 1 per 10,000 was a purely arbitrary choice. No support or rational is presented. The Agency should, therefore, withdraw that feature of the proposal and permit the current 2% rule to continue. We support the conclusion that the functional groups listed In .250(d)(6)(H) are safe and should be permitted. G. Carbon Content Proposed section .250(d)(2) would exclude polymers containing less than 32% carbon. The Preamble, at III.B.2, p. 33927 of the Notice states that this Is because the Agency found no polymers with less carbon content in Its PMN review. However, the support documents also state that the sample surveyed contained only 1% of examples containing halogen (document 54, p. IV-9) and that many subclasses of so-called "exotic" polymers were excluded from the final analysis. The Agency has overlooked several major commercial families of polymers which have widespread applications In foods and health uses and in other Important areas, which would be excluded If this proposal should be finalized. These Include: a) Fluorlnated polymers such as polytetrafluoroethylene (24% C) or polychlorotrlfluoroethylene (21% C) which are used In cookware, scientific Instruments, medical Implants, and nuclear energy. b) Polymers containing vinylIdene chloride (27-30% C) which are used In food packaging and many other home applications. c) Chlorinated polyethylene and chlorinated PVC (about 28-30% C), which are used for domestic hot water piping and many Industrial applications. d) Glass (0% 0), which Is ubiquitous. The arbitrary determination of 32% as a cut-off has no basis in health or scientific fact, and Is derived from an Incomplete and skewed sampling. It Ignores the existence of major product 13 APOOOI8797 lines which would be excluded by Its promulgation. There are no data presented suggesting that It would, In fact, offer protection from potentially hazardous solutions. This portion of the proposal should be withdrawn as Ineffective and capricious. Risk Assessment A. Vinyl Chloride The quantitative risk assessment procedure used by the Agency In this Notice Is extremely conservative. The risks projected are several orders of magnitude greater than the most probable actual risk. However, we agree with the Agency that when such a preliminary estimate shows no significant risk, there need be no concern, and the Agency need not undertake the more difficult task of preparing a realistic estimate. Such Is the case for the risk from exposure to polymers. However, when a preliminary risk estimate does give a result that Is In the area of concern, the next step ought to be to reestimate the risk by sounder procedures. The Agency has not done this for the potential exposure to residual monomers, and has thus relied on estimated risks which are several orders of magnitude too high. See our comments to companion Docket 50032A1 for a more detailed critique of the risk assessment methodology used here. However, even without developing a more realistic reestimate for residual vinyl chloride, the Agency has made two serious errors in the risk calculation for that substance. Corrections of those errors will yield a risk estimate considerably below that which the Agency considers "significant". 1. Incorrect Potency Values In Table 5, p. 43 of the Risk Analysis document (reference 47 of the Notice), the Agency presents In line 3 the risk estimates for two potencies (B-values), one for a value of 0.02, which is that calculated by the Agency for vinyl chloride Itself, and another for a value of 2.0, based on a calculated value for acrylonitrile. Only the high level risk calculated from the assumed acrylonitrile value Is noted as "significant". That for the vinyl chloride Is below the significance level. Yet the Agency uses the acrylonitrile calculation to exclude vinyl chloride from the exemption process when it has a value for vinyl chloride Itself which shows that the calculated risk is not significant. The Agency Is In error In using a value calculated for another substance when It has a value for the substance In question. Had the Agency used the proper value of B for the residual monomers from PVC, It would not have determined that vinyl chloride residuals were of concern. The Agency should, there fore, not Include vinyl chloride as a monomer requiring exclu sion from this proposed exemption process. 14 APOOO18798 Vie would point out that the potency value of 2.0 for acrylonitrile Is not that used by the Agency In the risk assessment document In Docket 50032A1, where the value of 0.37 was listed In Table Al, and Is different still from the value actually given by the author cited as the source for Table Al. The Agency should explain this discrepancy In values, as well as Its use of an Incorrect value. 2. Incorrect Residual Monomer Levels Further, In order to obtain the risk values which It did calculate, the Agency used, In Table 3, p. 41 of this document, a residual monomer value of 4%. The very limited data set which the Agency used In this exercise contained no materials In the molecular weight range of commercial PVC. See Table 2, p. 7, which shows a maximum Mn value of 50,000, whereas commer- clal PVC is above 60,000. Even so, the mean residual monomer value for the class of candidates with molecular weights above 10,000 was only 0.5%, not 4%. In addition, the Agency should have known that It has a regula tion, 40CFR61 (Subpart F), which prohibits the production of PVC with residual monomer greater than 400 ppm, or 0.04% In the slurry. The actual residual monomer level after separation from water and drying, when any significant exposure to the worker could occur, is substantially lower than that figure. See EPA 450/3-82-003, where It Is shown that commercial product often Is below 50 ppm. Thus, the projected risk Is at least 100 times overstated by this error alone, and the value In Table 5 should be no more than 4.5 x 10**7, under the conditions that may be used in the production of PVC. We believe that the overall procedure used here is Incorrect and that for vinyl chloride In particular Is based on unsound methodology. See Barr, "Risk Assessment for Vinyl Chloride in Perspective11, Paper 82-9.2, 75th Annual Meeting of the Air Pollution Control Association, New Orleans, June 20-25, 1962, copy attached, and our comments to Docket 50032A1. However, it Is not necessary to open that argument In this matter, for the Agency data presented In the record of this proposal shows clearly that the Agency procedure does not calculate a significant risk for worker exposure to vinyl chloride when PVC Is produced under the existing Agency regulation for Its manufacture. Therefore, the Agency should not exclude vinyl chloride-containing polymers from the exemption process based on an assumed risk to workers. B. Water Soluble Polymers The Agency has used the same worst case type of calculation to produce a postulated risk for water soluble polymers, without consideration of any specific material. We have shown above that 15 APOOOf8799 PVOH Is not toxic by Ingestion at low concentrations or from other modes of contact. Further, Its usefulness as a soil conditioner (see Finch and Klrk-Othmer, loc. cits.) is based on the fact that It adheres strongly to soil particles. It Is cross-linked and rendered Insoluble by the multi-valent Ions which are present In the soil. Thus, even If it were to be transported to the soil as a solution, It would be removed by the soil, and if It did reach an aquifer, no harm would come to those consuming that water. We believe that the Agency should consider the actual risk of the specific polymeric structure, rather than regulating all materials after hypothesizing a risk based on worst-case conditions. Consider ation of the data for PVOH will show that It poses no environmental risk because of Its water solubility. The Agency should not base the risk assessment for PVOH on substances of totally different composition and properties, as It did In this matter. We would note that other offices of the Agency, such as the Air Office, have encouraged the development and application of water soluble polymers. For example, these are used In the "solventless" surface coating applications because of their reduced Impact on the environment as compared to solvent-based coatings. This proposal would be counterproductive to the effort by the Agency to reduce volatile organic emissions. We also call attention to the discussion In the Notice document, p. 33 of document 50 of the record, which points out that polymers of molecular weight greater than 5,000 do not enter Into biological systems. As we pointed out In Sec. III.I above, PVOH has no physio logical effects In animals, even when Is Introduced Into the blood stream at reasonable concentrations. Paragraph .250(d)(6)(H) of the proposal states that aliphatic hydroxyl groups are not of concern. This Is the only functional group present In PVOH In any significant amount. Thus the Agency should have no concern for Its presence, of the fact that It renders the product water soluble In some cases. For these reasons, we believe It proper for the Agency to specify PVOH as a class of water soluble polymer not covered by the exclusion from the exemption. Polymers Designed to Degrade The risk assessment document makes no effort to develop a quantita tive risk for degradable polymers, but merely assumes that they may produce a harmful product as they degrade (p. 70). The attached paper by Casey and Hanley shows that PVOH Is completely mineralized (goes to CO2 and water) by biological degradation, and therefore will not produce toxic substances. The attached letter to a customer gives further experimental detail on the data heading to that conclusion. It does not revert to monomer on degradation, but If It did the monomer Is not toxic. It does not form oligomers, but 16 APOOO18800 Is converted completely to harmless natural products. The data available to us Indicates that the biological degradation does not proceed by Internal chain scission, but by the conventional way, ^-oxidation steps from the end of the chains. Therefore, In the absence of evidence supporting Its assumptions, and given evidence as to the safety of PVOH, the Agency should not rely on supposition to exclude PVOH from the exemptions proposed here. VII. Improper Exclusionary Action In view of the consistent low toxicity of and exposure to high molecular weight thermoplastics, such as PVC and PVOH, which are reported In the risk assessment document and the supporting mitre report, the Agency has taken a most unusual position as to their eligibility for the exclu sion process proposed here. A major reason for that appears to be that this proposal is designed for an 111-deflned group of low molecular weight prepolymers, and not for the greater class of structural polymers. Thus, this form of risk assessment Is Inappropriate for the PVC and PVOH families of polymers and ought not to be applied to them. Another reason for the difficulties with this proposal may be that the Agency appears to have reversed the normal rulemaking procedures, and Is proposing exemptions from a procss that is not yet established by formal rule. Without firm information on the process for which the exemptions are being granted, we are unable to evaluate adequately the costs or benefits of the exemptions, and neither is the Agency, of course. We recognize the value of reducing the regulatory burden, that In order to appreciate that reduction It Is necessary to have In hand a measure of the original burden. We do not have that now. We urge the Agency to reconsider the potential hazards of these classes of substances and not to exclude them on the basis of assumptions not applicable to them. We see no evidence In the risk assessment document which points to any significant risk to humans or the environment from the manufacture or use of these classes of products. VIII. Summary In summary, we offer the following suggestions to the Agency on this proposal. 1. The Agency should make a clear statement that this proposal does not contemplate structural polymers, and then proceed to propose the elimination of structural polymers from the inventory require ments. 2. The Agency should reorganize the proposal into various classes of polyesters, prepolytners, and final polymers based on more suitable criteria. 3. The Agency should not provide a blanket exclusion for water soluble polymers, but should allow classes with suitable composition and functionality to be eligible for the proposed exemption. 17 APOOOf8801 4. The Agency should not exclude chlorine - containing polymers as a class without specific Justification from consideration of the hazard of the particular polymer. 5. The Agency may not exclude classes of polymers from the exemption because of concerns for workplace or environmental exposure to the residual monomers because these effects are regulated by other statutes and regulations which the Agency is bound by Sec. 9 of the TSC Act to utilize first, should there be a hazard. Neither can the Agency use Sec. 5(4)(4) In place of the SNUR procedure. 6. The Agency has no basis In fact to exclude PVC or PVOH polymer classes from exemption under this proposal. 7. The economic analysis should be revised on the basis of realistic development costs for the required testing, and a more probable number of exemptions which may actually be sought. This proposal Is unlikely to be used by any significant fraction of the producers of new polymers. 8. The polydlsperslty and molecular weight criteria which are proposed are arbitrary, and should be reestablished on the basis of scien tific data. 9. The risk assessment Is based on inappropriate assumptions and incorrect values, and should be withdrawn. We support the basic concept of this proposal. Reduction of the burdens to Industry and the Agency can provide considerable benefits to the public without an increase In risk. The Agency has made a start at this program, but we believe that the suggestions outlined above will make the program more cost effective, and will place it on a much sounder scientific basis. This is needed, for It Is our belief that the proposal, as presently stated, will not be useful to either the Agency or the regulated public, and thus will not achieve Its stated goals. 18 APOOOt8802 POLYVINYL ALCOHOL BIODEGRADATION BY OXYGEN-ACTIVATED SLUDGE J. P. CASEY and D. G. MANLY Air Product* and Chemical*, Inc., Allentown, Pennsylvania 18105, U.S.A. Summary VINOL 325 Polyvinyl alcohol (PVOH) may be totally biodegraded as illustrated by controlled respirometric assays. Organisms which consume PVOH are viable in mixed culture activated sludges as determined by both synthetic and actual domestic wastewater studies in which PVOH was added to influent to a small scale multi-stage OASES correlation unit. Mixed culture growth rates analysed by appreciation of oxic solids residence time and clarifier damping factors permit sequential analyses of Nitrosomonas, Nitrobacter, and PVOH-degrading organism proliferation in activated sludge operated at successively lower dilution rates. A step increase in PVOH concentration allowed an initial calculation of PVOH organism growth rate within the oxygen activated sludge system of n m 0*34 day*1 at 20 1*C. A second scratch startup and examination of PVOH organism proliferation at a lower dilution rate confirmed this growth rate. Efficiencies of mixed culture PVOH degradation reached 13 mg PVOH/hr/g VSS with 3 hr influent residence time for a domestic wastewater primary clarifier effluent. Organisms degrading PVOH in mixed culture remained viable under H202 treatment conditions which were toxic to filamentous and nitrifying organisms. Systems removing >90% of 50 mg/Iitre PVOH, >95% of 40 mg/litre NH, and >90% of BOD s were operated with excellent macroscopic sludge properties. DISCUSSION In light of early documentation of microbial metabolism of PVOH to C02 and H20 (Nord, 1934) and later reference thereto (Pritchard, 1970), it is surprising that aqueous solutions of PVOH were long accepted as minimally biodegradable. This conclusion has been affirmed by reports of 0*2% (Clemson, 1971) --1% (Burr, 1971) BOD/weight ratios determined by Standard Mtthodr (APHA, 1971). The weakness of BOD testing to determine latent* biodegradability has been appreciated (Burr, 1971), yet other more rigorous methods have been employed to document the refractory nature of specific commercial PVOH products (Wirick, 1974)! Because of the extensive use of PVOH as a textile sizing agent and the need for nonpoiluting textile wastewater treatment systems, considerable recent work on PVOH has appeared. A study reporting variable long-term BOD results for PYOH (Porter and Snider, 1974) protested the difficulty in relating controlled biodegradability tests to wastewater treatment operations. An integrated study of textile wastewater treatment technology dealt with activated sludge acclimatization to, and removal of, PVOH on a 2 litre scale (Bryan, 1972). A 20 litre and pilot scale study. (Baines, 1973) documented 819 AP000I8803 820 /. p. Casey end D. C. Manly PVOH removal by activated sludge. Further work has generated dimension* less data proposing a loading ratio of (M COD/MLSS and a solids aeration time (Sat) of 8 (g MLSS/LXdays) for efficient treatment (Hahn tt al., 1975). Extensive work by Nippon Synthetic Chemical Industry Co., Ltd (Nishikawa and Fujita, 1975) has resulted in proprietary wastewater treat* meat technology claims involving additive and process control tactics, yet some textile plants have performed satisfactorily on an independent basis (Anon., 1974). Clearer understanding of the fundamentals ofPVOH microbial metabolism has been published (Suzuki it al., 1973), but no satisfactory pure culture or mixed culture growth rate data are presently available. Such information is critical for application of bioengineering principles in wastewater treatment. The present study was undertaken to provide such information and develop Fig. / Analyses of observed growth rate. O SPRR Stages 1-2: a SPUR Stages 1-3 O SPUR Stages 1-4; Q SPRR Stages 1-3. Fitted symbols represent data for least squares tine fit. Petted I, slope 0*120 day-*. Period II, slope 0-188 day-*. Polyvinyl Alcohol Biodegradation by Oxygen-aciieated Sludge 821 design criteria for treatment of wastewater containing polyvinyl alcohol. Multiple-stage OASES correlation unit operation permitted stage by stage substrate determination on a daily grab sample basis. The interstage change in VINOL 32S concentration normalized to MLVSS level and stage residence time permitted calculation of a Spedfic PVOH Removal Rate (SPRR) expressed in mg PVOH/hr/g VSS. With the viable assumption that active mass degrading PVOH constituted a small fraction of the total MLVSS, the change in SPRR could be used to assay increased or decreased presence of PVOH-degrading bacteria. Given the assumption that SPRR is proportional to PVOH-active biomass (X), the expression p -- J iX\dx}X to obtaia the growth rate ofactive mass could be solved by obtaining the slope ofIn SPRR plotted nr. days of operation. Two summary periods of analysis are presented in Fig. I. The volume* weighted averages ofdaily values of SPRR for multiple stages inclusive of the first were used fora least square line fit. Analysis ofresponse to a step increase of VINOL 325 from 50 to 100 mg/litre during period I at constant flow rate results in an observed growth rate of 0*120 day*1. Analysis of the increased rate of VINOL 325 degradation following trace seeding with supplemental active organisms during period II results in calculation of observed p of 0188 day*1. In each case the actual organism growth rate may be calculated after correction for the unit dilution rate, for the observed rates ore reduced at higher system dilution rates. Furthermore, a factor which expresses the damping effect of clarifier inventory on observed system response is required. Given rigorous daily and summary average period data, this damping factor is easily calculable from reduction ofa set offull system rate equations. Table I presents the specific data utilized to calculate actual growth rates p /^u. + Table. I Period Dates f day* Mat (day *0 Condition coefficient MLVSS (ms/litre) Aeration volume (L) VSS produeed/day Ci) SRT (day) fjtoa - i/SRT (day-i) / Mum +/?<** (day-i) T stage 51 CO T last stage (*C) I 10/29-11/2 J 0-120 0*989 4 438 290 16 12-4 3-T 5*901 0*170 1*353 0*333 22*1 0*3 21*0 0*4 // 2/28-3/8 9 0-188 0*973 4482 174 40 10-9 5*3 16*51 0*060 1*468 0*338 20 3 1-2 19*0 i 1*4 //W These are 0*33 day'1 in response to the step increase in loading and 0*34 day'1 for response during the period of higher SRT. In mixed culture with activated sludge in the range of 19-22'C, the organism doubling time is therefore of the order of 2 days. Depending on the solids residence time of the chosen activated sludge system and the damping factor provided by ineffectual darifier inventory, the time for doubling cf observable organism presence may be substantially higher than the 5*8 or 3*7 days noted in the periods analysed above. - AP00018805 822 /. P Casey and D. <7. Manly This work demonstrates that definitive mixed culture growth rate data can be generated for organisms which biodegrade PVOH in mixed industrial* domestic wastewaters. Furthermore, the current scope of practicable bio* engineering technology (Landis at aL, 1974) can be utilized for the design and operation of activated sludge systems for PVOH removal MATERIALS AND METHODS VINOL 325, degree of polymerization 1725 25, degree of hydrolysis 98-99% and VINOL 540, degree of polymerization 2400 SO, degree of hydrolysis 87-89% were obtained from commercial lots produced at Air Products and Chemicals* Calvert City, Kentucky facility. PVOH*3 was obtained from a commercial lot imported for use as a textile sizing agent, and Is a crotonic icid*vinyl alcohol co-polymer of medium viscosity and 94% degree of hydrolysis. Suspended solids, BOD and COD measurements were performed following 'Standard Methods* (APHA, 1971). Nitrification of ammonia in the BOD test was supressed by addition of 1-6 x 10"* m allylthiourea. Filtered BOD and COD data refer to filtrates obtained from aspirator vacuum filtration using 2*4 cm Reeve Angel gloss fibre filter paper. BOD dissolved oxygen (DO) measurements, mixed liquor DO measurements, and dynamic oxygen uptake measurements were performed using a Yellow Springs Instrument stirred BOD probe model #54. Ammonia, nitrite, nitrate plus nitrite, and hydroiysable phosphate deter minations were performed on filtered samples using Technicon Autoanalyser II methods. VINOL concentration determinations using a boric acid-I2/Jj" procedure (Finley, 1961) were initially performed using a Perkin-Elmer Model 202 spectrophotometer, then automated for unit operations by adaptation to the Technicon Autoanalyzer II at 80 samples per hour using a 660 nm colourimetric filter for a full-scale range of0-50 mg/iitre VINOL 325. Unit operations were performed using plexiglas aeration chambers in series. Submerged candle spargers supplied 02/air/N2 mixtures to the openstaged mixed liquor in which the gas pressures to each stage were separately reduced and gas flows were separately regulated and monitored by flow tubes. This gas system permitted simultaneous variation of desired DO levels and gas flows providing intrastage mixing at approximately 0*15-0*20 hp/1000 gal. Dynamic oxygen uptake measurements taken serially beginning with the final stage were facilitated by the independent gas flow controls, allowing dilution corrections of the form dOj/dir -- (DO, -- DO,+ J/dr + (DON. t -- (DO, + DO(+1)/2) (Q/Y) for the Nth stage upon terminating gas flow to that stage and providing mechanical stage mixing while recording the DO. Domestic wastewater was obtained twice a week in epoxy-lined 55 gallon drums from the primary clarifier overflow at the Easton, Pa. sewage treatment plant. Desired concentrations of PVOH were obtained by addition of 5% PVOH concentrate to the barrels. Barrel contents were stirred mechanically to maintain influent solids suspension and were removed, using a ColeParmer positive displacement pump capable of drawing influent from the barrel bottom through a inch mesh wire screen protecting the tip of a i inch ID plexiglas tube connected to tygon tubing on the pump suction side. Activated sludge recycled from the inclined cylindrical bottom of an 18 litre. Polyvinyl Alcohol Blodegrodatfon by OxygernKtivotcd Sludge 823 24 inch tall, 6 inch OD clarifier equipped with a 10 inch deep centrewcll of 2 Inches OD and sludge rake was introduced, via a second peristaltic pump, alongside the influent directly into the first aeration stage. Daily data included determinations of DO, pH, temperature, TSS, YSS, NH, - N, NO," - Ny NO,' + NO,' - jV, and PVOH for influent, effluent, and each aeration stage. The oxygen uptake rate (OUR), sludge volume index (SVI), and 0,/air/N, gas flows were recorded for each stage. A zone settling velocity (ZSV) and 30 minute stirred SVI (SSVI) were deter mined on the last stage mixed liquor in a 1 litre graduate using a 6 rph rake. Influent and effluent SS, BOD, and COD were determined at the beginning of the data day on grab samples and their filtrates obtained after overnight steady-stage operation. The Calcomp figures herein present 3-day running average data for daily values except for initial data days at new process conditions, which are represented by a 1-day and 2-day value, respectively. RESULTS VINOL 325 was first demonstrated to'oe nontoxic and noninhibitory upon short-term testing by addition to activated sludge organisms degrading a glucose-based synthetic wastewater. Response of 2500 mg/litre MLV5S from a state of endogenous oxygen uptake to a state of maximum oxygen uptake following addition of 1000 ing/litre glucose was unchanged upon addition of 400 mg/litre VINOL 325. A second indication of nontoxidty was obtained in seeded BOD tests using unacclimatized biomass. In tests of 5-20-day duration, the change in DO of the seeded BOD blanks was not substantially exceeded, but was equalled by, the change in DO (up to 4-5 mg/litre in some heavily seeded tests) of the BOD tests containing 3-7 mg/litre VINOL 325. A survey of textile wastewater treatment plants was undertaken in parallel with initial acclimatization tests, and consisted of analytical work docu menting PVOH removal by select plants, then collection of mixed liquor sludges capable of removing PVOH. A culture from one textile wastewater treatment plant in the Southeast was enriched in fill and draw tests to provide seed organisms to document PVOH biodegradation. Die-away analyses of VINOL 325 confirmed by COD analyses (COD/VINYL 325 - 1-64 g/g, theory ~ 1 *82 g/g) indicated removal rates of 9-1S mg/hr/g VSS. . Supernatant from an endogenous mass of sludge acclimatized to PVOH was used as seed in a series of BOD tests performed without and with 3 x 1Q~* m ATU to inhibit nitrification. In addition to replicate seed controls, each substrate was tested at 10.15, and 30 x dilution ofa 100 mg/litre stock solution. DO levels were monitored at 5-day increments through 30 days or until DO depletion, at which points PVOH, NH, -- Nt NO,' -- V, and NO," + NO,' --N levels were monitored by Autoanaiyzer II test methods. Figure 2 presents summary plots of BOD data indicating levels of precision where multiple samples remained undepleted. Table II presents, based on stoichiometric oxygen consumptions for NH, -- N to NO," -- TV; NO," -- N to NO," -- N\ and PVOH to CO, and H,0, calculated and observed charges in DO levels. The agreement in nondepleted samples strongly suggests total oxidation of VINOL 325 and, after an initial lag, of the less fully hydrolysed VINOL 540. PVOH-3 proved substantially less degradable by the seed organisms acclimatized to VINOL 325. 824 J. P. Casey and D. C. Manly V1N0L 325 VINOL 540 PVOH-3 DAYS Fig. 2. Thirty day BOD tests without and with ATU inhibition of nitrification, corrected vs. corresponding blanks. / indicates Standard Deviation of nendepleted samples of varying dilutions of IOO mgllitre VINOL 325. Table II DISSOLVED OXYGEN BALANCES IN 30 DAY BIODEGRADATION OF 3*33 mg/Iltre PVOH APYOH ADO PVOH ANOs, ADO NOs, Calculated Actual sum sum ADO ADO VINOL 325 VINOL 325 with ATU VINOL 540 VINOL 540 with ATU 3-33 2 98 1-58 3-33 5-46 4-88 2-61 5-49 0-38 0-08 0-46 0-06 1-72 0-34 2-08 0-26 7-18 5-22 4-69 5-75 7-10 4-90 5-25 4-90 i ii APOOOt8808 Polyvinyl Alcohol Biodegradation by Oxygen-activated Sludge 825 Unit operations using a synthetic wastewater seeded with sludge enriched in PVOH acclimatized organisms followed successful initial fill and draw die-away analyses. Upon introduction of seed sludge to a stable synthetic wastewater unit operation unable to degrade PVOH, proliferations of filamentous organisms present in the seed sludge proved deleterious to unit operations. Following treatment of recycle sludge with 0*1 g H202/gTSS to oxidize filaments of Sphaerotilus natans, all nitrification within the system was suppressed, but PVOH removal capabilities remained. Stable operations were then attained at low organic loadings employing n high degree of initial staging (Casey et aL, 1975). Nitrification plus VINOL 325 removal capabilities of activated sludge were examined for synthetic wastewater supplemented with VINOL 325, for a synthetic waste consisting solely of VINOL 325 as a carbon source, then for a domestic wastewater supplemented with VINOL 325. Data for unit operations from 10/16/73-3/20/74 have been selected for review, and are presented in Figs. 3-12. A chronology is presented in Table III Table HI SUMMARY CHRONOLOGY Date 10/26* 10/30* 11/3* 11/21* 12/1* 12/5 1/3* 1/142/1- 2/13* 2/26 2PM 3/14 3/21 One day removal of PVOH from Influent Step increase in VINOL 32S from 50-100 mg/litre Increased flow New unacciimatized unit operation Decrease VINOL 325 from 100 to 50 mg/lltre Auxiliary unit operation studies Increase flve stages or aeration volume by 50% Increase aeration volume by 67%, to seven stages Increase flow to build solids level Decrease flow Addition of 100 mg/litre alkalinity to influent Seed sludge addition, 5% of inventory * Omit VINOL 325 addition Alternative unit operation studies * Major process changes, figures restart 3-day running average. for data from a previously initiated unit operation and operation reflecting performance of sludge produced in an OASES correlation unit not previously exposed to PVOH. At 4 hr influent detection time for a five stage 16-litre unit, operation with 33% sludge recycle resulted in 3 hr nominal residence time (Fig. 3). Easton wastewater of moderate strength contained 520 mg/litre COD (Fig. 4) and 120 mg/litre BOD* (Fig. 5). The COD included a contribution of 80-90 mg/Htre from VINOL 325 supplement, but the BOD s did not reflect VINOL 325 presence as the influent 5-day BOD tests were run without seed. With a nominal 6000 mg/litre MLSS, 4800 mg/litre MLVSS (Fig. 6) under aeration with stable sludge properties ($VI of 60ml/gTSS and ZSV of 6 ft/hr), removal of35 mg/litre ammonia was complete by nitrification to NOs~ + NOa" -- N (Fig. 7). Removal of 60 mg/litre VINOL 325 was also complete (Fig. 8). Following 10/25 data, the fresh daily domestic wastewater influent was not supplemented with VINOL 325. The 24-hr absence of substrate had sub stantially no effect upon overall removal efficiency upon re-addition jo VINOL 325 the following day. RCSlOCNCE TIME {HOURS} INFLUENT Fig. 3. Domestic wastewater detention time In OASES correlation ait. Fig. 4. Domestic wastewater tmfiltered (V) andfiltered (F) COD values. AP00018810 L*??i9Q0dV i I 'rpqorpjpvfdnu }]jvfoa puspm Jonbfi pixjw *p J}j j. ** M IZ CZ u 82* 8 J. P. Casey ami D. 0. Manly 73 73 73 74 74 74 Fif. 7, Domestic wastewater ammonia and oxidation thereof. 74 APOOOf8812 l88l000dV Aaunjig* [oaouiij Sq08 P" OOO tytiiuo<j 'Q( '*ij 'luipooi PfUVlJO MOMWOM ailtMUOQ 4 -tu 678 flpnjS pfitniisthuatiTQ /q i/o/jeppjJjpcjg \cqos\y jXufaKjoj 830 s J. P, Casty and D. G, Manly 8 APOOOf88f4 Polycinyi Alcohol Biodegradation by Oxygen-aetkated Sludge 831 Following 10/29 data, the VINOL 325 concentration was doubled to 100 mg/Jitre. Significantly, overall removal efficiency was maintained and PVOH removal remained above 90% and COD removal above 85%. Following 11/2 data, the influent and recycle flows were increased by approximately 30% to give a influent detection time of 3*2 hr and nominal residence time of 2*4 hr. VINOL 325 concentration rose initially to 18 rag/ litre, but was then reduced daily despite the higher flow conditions. With slightly increased flow and lower MLVSS levels resulting from greater hydraulic throughput in the clarifier, hence less dense underflow despite essentially similar macroscopic sludge properties, the unit operation proved sensitive to changes in influent strength over the next period of operation from 11/9-11/20. This F/M (Fig. 9) sensitivity showed parallel responses of OD removal, nitrification, and PVOH removal efficiencies (Figs. 10-12), for as influent strength increased, then decreased, % ammonia removal, % nitrification, and % VINOL 325 removal decreased, then increased. These operations demonstrated borderline conditions for system efficiency. To ascertain conditions necessary to commence stable PVOH removal, a parallel unit operation which had not been exposed to VINOL 325 and which had a history of 7-9'C activated sludge operation was dedicated to continuing VINOL 325 studies at20C. Beginning 11/21 at control conditions identical to the former operation, VINOL 325 was added to domestic substrate at 100 mg/litre. Reductions of VINOL 325 of 12-8 mg/iitre during the first 3 days of operation were followed by a period of essentially zero reduction through the next week, after which time the influent VINOL 325 was reduced to 50 mg/litre. Over the next month, during a period of auxiliary investigations, the VINOL 325 removal increased slowly to 8-10 mg/litre, representing 15-20% overall removal efficiency. Following the Christmas/New Year hiatus in full data collection, expansion of the aeration volume from 16 to 24 litres to give five liquid stages at 8 inches liquid height of 2*4, 4-8, 4*8, 4-8, and 7*2 litres was undertaken after data on 112. Operations continued at 4-0 hr influent detection time with 33 % sludge recycle to give 3*0 hr nominal residence time through 1/17, encompassing a period of low influent strength, total nitrification, to nitrite, and rather steady removal of 8-10 mg/litre VINOL 325. After 1 /17 data, two 8-litre stages were added to give a total aeration volume of 40 litres composed of seven stages. Dilution of the aeration plus clarifier inventory resulted in an MLVSS level of --1700 mg/litre. At this low solids level sludge settling rates approached 15 ft/hr, resulting in increased weir losses from too rapid a settling rate in the clarifier. Over a 12-day period with only sampling losses constituting sludge wasting, the VSS produced per day of 13-8 g resulted in an inventory increase of only 3-4 g/day due to weir losses of 9-0 g/day in addition to the minimal wasting of 1-4 g/day. To effect an increase in system inventory yet attain solids residence time control through daily wasting, the influent flow was increased by 50 % and the percentage sludge recycle was increased from 33 to 40% of influent flow. After reaching > 3000 mg/litre MLVSS with controlled daily wasting on 2/12, the influent and recycle were reduced to give an influent detention time of 5-0 hr and nominal residence time of 3*6 hr from 40% sludge recycle. These conditions were maintained at 19-22*C through the following weeks of controlled wasting to obtain MLVSS level increases to 4000,4500, 4750, and 5000 mg/litre, respectively. 832 J. P. Casey and D. Q, Manly Nitrification to nitrate increased at a rapid rate from 2/13-25, at which point some reduction in ammonia removal rate for the moderate strength (100 ml/l BODj), high ammonia (40 mg/l NH3 -- N) wastewater was noted due to alkalinity losses caused by nitrate pH depression in the terminal aeration stages. Addition of sodium bicarbonate to the influent equal to 100 mg/litre alkalinity as CaCO> was instituted 2/26 and eliminated the ammonia breakthrough. VINOL 325 removal of IQ-12 mg/litre was constant during operation through 2/27, at which time previously wasted sludge acclimatized to VINOL 325 in fill and draw tests was seeded at 5% of total inventory (12*6 g VSS to 265-3 g YSS) into the unit operation. At relatively constant influent strength applied to 4500 mg/litre MLVSS, the PVOH removal levels were 11,16,12,16, and 16 mg/litre VINOL 325 for sequential days during which sludge pro duction averaged near the prior period norm of 12 g/day. On the following 3 days of operation, the next biweekly influent wastewater shipment was applied PVOH removal increased to 37,49, and 55 mg/litre as influent BOD dropped from the previous shipment value of ~ 100 mg/litre to --40 mg/litre and daily sludge production was approximately halved. VINOL 325 removal was maintained at greater than 90% of a nominal influent concentration of 50 mg/litre for one week, then unit operation parameters were maintained with the exception that YINOL 325 was removed from the influent. REFERENCES Anon. (1974). Blair's trained bugs eat PVA waste. Textile World, February 1974. p.43. APKA, AWWA, WPCF (1971). Standard Methods for the Examination of Water and Wastewater, 13th Ed., AFHA, Washington, D.C Baines, F. C. (1973). Biodegradation of Polyvinyl Alcohol, AATCC Symposium, The Textile Industry and the Environment, May 22-24,1973. Bryan, C. E. (1972). Dept. ofTextiie Chemistry, School of Textiles, North Carolina State Univ., Water Pollution Reduction Through Recovery of Desizing Wastes. U. ETA Clean Water, Water Poilut. Control Res. Ser. 12060 EOE 01/72. Burr, F. K. (1971). Textile waste treatment. In Textile Technology, Kirie-Othmer Encyclopedia of Chemical Technology, 2nd Edn. Supplement Volume. J. Wiley St Sons, Interseieace, New York. 980 pp. Casey, J. P.. McDowell, C. S., Spector, M. L., and Zupko, A. J. (1975). Non Bulking Activated Sludge Process. U.S. Patent 3,864,246 assigned to Air Products and Chemicals, Inc., 4 February 1975. Clemson University Department of Textiles (1971). State-of-the-Art of Textile Waste Treatment, A Study Conducted for the Water Quality Office of the EPA. Grant No. 12090 ECS. Finley, J. D. (1961), Spcctrophotometric determination of polyvinyl alcohol in paper coatings. Anal. Chem,, 33,1925. Hahn, W. C., Barnhart, E. L., and Meighan, R. B. (19?5)t The Biodegradability of Synthetic Size Material Used in Textile Processing. 30th Annual Purdue Industrial Waste Conference, Purdue Univ., West Lafayette, Indiana, May 6-8, 1975. Landis, J. G., Casey, J. and Hartzog, D. G. (1974). Oxygen Activated Sludge: Design by Waste Analysis and Modelling. 47th Annual WPCF Conference, October 6-11, 1974. NishQeawa, H., and Fujlta, Y. (1975). Polyvinyl Alcohol Degradation Techniques Using Microorganisms. Chem. Economy Eng. Rco., 7, 33. Nord, F. F. (1936). Naturwiss, 24,763. AP00018816 Polyvinyl Alcohol Biodegradation by Oxygen-activated Sludge 833 Porter, J. J,, and Snider, E. H. (1974). Long-Term Biodegradability of Textile Chemicals. Third Annual Clemson Untv. Textile Pollution Control Conference, January 23-25, 1974. Pritchard, J. G. (1970). Polyvinyl alcohol), Basic Properties and Uses. Gordon and Breach, London. 117 pp. Suzuki, T., Yoshihlro, I., Yamada, M., and Tonomura, K. (1973). Some character istics of Pseudomonas 0*3 which utilizes polyvinyl alcohol. Agr. Biol Chem., 37, 747. Wirick, M. G. (1974). Aerobic biodegradation ofcarboxymethyl cellulose. /. Water Poiiut. Control Fed., 46, 512. AP000188I7 PROCEEDINGS OF THE THIRD INTERNATIONAL BIODEGRADATION SYMPOSIUM Editors J. MILES SHARPLEY Sharpley Laboratories Zrrc.,. Fredericksburg, Virginia, and Virginia Common- wealth University, U~S.A* and ARTHUR M. KAPLAN U.S. Army Research and Development Command, Natick, Massachusetts, U.S.A. APPLIED SCIENCE PUBLISHERS LTD LONDON APOOOf8818 (z^cAl^PAcduct^) CHEMICALS GROUP Attalat4r+,T Air Products and Chemicals. Inc. Industrial Chemicals Technology Box 538, Allentown. PA 1*105 Tel: (215)481-4911 TWX: 510-651-3686 Ttlsx: 847416 April 1, 1982 Dear Enclosed for your use are graphs and tables which demonstrate efficient biodegradation of Etowah influent by biomass from the Springs Hills textile wastewater treatment facility. Also presented are respirometry data for both VINOL 205 and VINOL 325 which show equivalent biooxidation for the polyvinyl alcohol you will be using for fiberglass sizing and that previously discussed in APC1 technical literature on activated sludge. I think these data provide sufficient positive information to approach the Federal and State people for permitting, for the biomass used in these respirometry tests will be available for full-scale plant start-up. The Etowah activated sludge plant has four stages, each at 5000 gallons with a 7.5 horsepower submerged turbine. The airflow is specified at 1500 scfm to treat 100,000 gallons/day of influent at about 1000 mg/1 weight alcohol in open tanks. The process option of oxygen use in closed tanks has not been eliminated from future consideration. The bench scale simulation of the Etowah biotreatment technology now being conducted at ERG has recently been seeded with Springs Hills biomass known to biodegrade polyvinyl alcohol and should perform satisfactorily with these adapted bacteria. The commercial benchtop unit has a single aeration stage and an internal settling zone. It is being 'fed' influent at 90% - 1000 mg/1 VINOL 205 / 10% sanitary wastewater composited by ERG dilution from a 1% VINOL 205 waste concentrate. When we met with Peter Collins and Bruce Bartley of ERG in Ann Arbor on March 24 I recommended an increase in intensity of their study: o Monitor the biomass inventory daily to judge activated sludge biomass growth based on solids produced wasting inventory change 4- effluent losses - influent suspended solids. AP00018819 o Measure nutrient influent and effluent levels as NH3-N and P04-P to assure a 100:5:1 B0D:N:P ratio. Approximate stoichiometry for PVOH is TOC/VT = 24/44 = .5455 COD/WT = 80/44 =1.82 COD/TOC = 80/24 =3.33 BOD/COD = 2/3 BOD/WT =1.21 BOD/TOC =2.22 o Obtain daily COD data to evaluate unit operations. The filtration of influent and effluent through glass fiber fiter paper provides a proper filtrate for soluble COD analysis. o Obtain TOC data, requiring smaller sample size, to monitor the COD/TOC ratio as an indicator of substrate change. We agreed a quick APCI lab study using biomass and Etovah influent might provide site-specific feasibility data of immediate use. The appended electrolytic respirometry data were taken using an array of Oceanography International cells. Data were processed through miniand mainframe computers to generate the graphs. The summary tables itemize key data on initial and final cell contents and the critical values of percent TOC removed and 02/T0C. For the first run we added the influent as received from ERG to get the cells up on Friday, 26 March. We analyzed the biomass TSS at 5000 mg/1 and diluted to give 250 mg/1 TSS in the cells. Since the initial chain scission of PVOH is performed by extracellular enzymes ve ran the control of endogenous respiration versus two levels of ERG/Etowah influent with washed biomass as well as with the biomass as received. The washed cells are slower to exhibit significant oxygen consumption on the lower levels of initial TOC. By subtracting the oxygen uptake for cell l from that of 2 and 3, and doing the same for cells 4-6 a clear normalization is available and is used in the subsequent plots of rates of 02 use per unit time. The final plot of the log(rate) data is to obtain a linear least squares fit approximating the bacterial growth rate. The plots for PVOH-1 are a bit noisy due to the low substrate levels, but show a growth rate averaging .0188/hr, or .45/day, suggesting that at 25 degrees C, the temperature of the respirometer runs, an aerobic solids residence time of 1/.45 = 2.2 days should lead to retention of these PVOH-degrading bacteria. Qualitatively, then, the respirometry indicates a 'go1 for Etowah biodegradation. Quantitatively, the TOC removal is 79% (cell 3) to 94% (cell 6) and the 02/TOC = 2.7i g/g (average of 2,3,5,6). Because the run set up on 3/26 was essentially over on 3/29 due to substrate limitations, we continued the study by removing aliquots from each cell for analyses and adding VINOL 205 and VINOL 325 to the cells as indicated. I interpret the faster 02 takeoff in PVOH-2 for cells 3 and 6 as due to their higher prior level of substrate as much as due to any real difference in the biodegradability of VINOL 205 versus that of VINOL 325. The very close log(rate) data plots in the final presentations for PVOH-2, showing growth rates of .0168 and .0182/hr for VINOL 205 and .0186 and .0157/hr for VINOL 325, indicate no significant differences in biooxidizability. The summary data in the table for PVOH-2 document TOC removal of 94% to 96% in all cells and an 02/T0C ratio of 2.12 for VINOL 205 and 2.27 for VINOL 325. At higher substrate levels the test data for PVOH-2 are the better values to use for extrapolations to design, thereby indicating an average growth rate of .0174/hr and suggesting an aerobic solids residence time or 'sludge age* of but 2.4 days will maintain these PVOH-degrading bacteria in the system. Based on the maximum final solids level of 450 mg/1 TSS in cell 2 and the 02 consumption rates of 6-7 mg/l/hour in PVOH-2, the specific oxygen consumption rate in these tests is at least 14 mg/hr/gram TSS. Since the 02/T0C ratio is 2.2 for PVOH-2 and the T0C/WT is .546 for the VINOLs the rate of PV0H removal is 14 mg 02/hr/g TSS * TOC/2.2 02 * PV0H/ .546 TOC = 12 mg PVOH/hr/g TSS. With a 4 hour detention time and 5 g TSS/1 the PVOH removal ability of the bench scale unit, with this active a biomass, is about 240 mg/1 PVOH. To remove 1000 mg/1 PVOH a more active biomass or longer residence time is needed. The quickest way to optimze biomass activity is to increase the growth of the desired PVOH-degrading bacteria by operating at optimum growth rate conditions, say 33-37 degrees C. The above capacity analysis is a conservative evaluation that VINOL biotreatability is assured, but that operational success is going to be dependent on upgrading the activity of the seed biomass given the current detention time constraints. Please contact me through our polymer technology staff if I can be of further help. c.c. B.Bartley P.Collins L.Newman D.Stowe Attachments: Figure .. 1 Tables .. 2 Plots ...11 J/3 Sincerely yours; J.P.Casey Research Chemist + DC OXYGEN ELECTRODE SCHEMATIC DIAGRAM SHOWING THE BASIC OPERATION OF THE ELECTROLYSIS SYSTEM FOR MEASURING BOD 65 AP00018822 Cell # SEED RESPIROMETER RUN PVOH-1 123456 -------250 MG/L TSS! ERG-SPRINGS MILLS BIOMASS-___ /------ washed cells---/ /---unwashed cells'--/ SUBSTRATE Control Etowah Etowah Control Etowah Etowah Influent Influent Influent Influent INITIAL* PH 6.99 TOC (mg/1) 12.0 TSS 267 VSS %vss 208 77,9 6.95 14.6 285 236 82.8 6.94 32.1 298 222 74.5 6.96 27.5 286 232 81.1 6.92 31.9 276 226 81.9 6.97 53.1 281 223 79.4 FINAL PH TOC 7.01 11.2 6.90 11.5 6.91 15.4 6.89 13.5 6.84 14.4 6.90 15.1 A(68 hrs) 02 TOC %T0C Red'n 02/TOC 53.3 .8 6.7 7.95 58.3 3.1 21.2 18.8 104 16.7 52.0 6.28 86.3 14.0 50.9 6.16 98.4 17.5 54.9 5.62 135 38.0 71.6 3.55 AA 02 TOC %TOC Red'n 02/T0C 5.0 2.3 88.5 2.17 50.7 15.9 79.1 3.19 12.1 3.5 79.5 3.46 48.7 24.0 93.8 2.03 *Made up with BOD nutrients, P04 buffer with NH4C1 to give 28 ppm N per cell in 2,5 and twice that level in 3,6; titrated to pH 7 with H3P04, 20 mg/1 ailylthiourea added to inhibit nitrification. Etowah influent composed of 90% VINOL 205 wastewater and 10% sanitary effluent; measured TOC of material received from ERG 576 mg/1. Seed biomass received from Springs Mills/ERG = 5034 TSS, 4476 VSS. 032682-032982 NB 7018:51-54 J/j AP00018823 ELECTROLYTIC RESPIROMETER RUN P V O H - XC5\J oru OOrtnDEUQ OJ ''T COLA Uf I nj n la* <s> r- 1 CO OJ f* CO co o- LO ro CO co oz <s> LJ ^ CP E-- <xco o LO z u. LO 3 UJ Q Qi <S> LO LO CO CO 'T O' CO 3 CO <x o CO X LO CO X---* srti-ftMo (-- Z LO oujon LJ LjJ hdcu 3 OJ CO x--1 _J I> CO J 3 Lu -J Li_. H- y) Z ZJ? H-l LO -J CO x co OJ i- X 1 X 1 1 <T {-- CO <r f-- 3X0 3X <s> OJ COO t-LDUMZ O LU t--3 Z LlI^J qc UJ-J i-i Li. O. u. LO a: e-- z co t-- z H3H\ 3 HH C\O J JC<LJ> --1 <s> o \ \ U1 N S O' LUEEA XX LU LO OX UJ -r-i LO CO LO x <r CO 3 3 3 33 <s <c 3 z 3 rr -^r 1111 ti *- ru co LO CP --j -j -j J -j _i _j -J nJ UJ LULU UJ UIU O OO O oo AP00018824 SZ88L000dV ELECTROLYTIC RESPIROMETER RUN P V O H - -CELLS 5 ,6 RESPIRATION OF UNWASHED BIOMASS CORRECTED FOR CONTROL CELL BIOMASS ENDOGENOUS RATE . AS ABOVE, NUTRIENTS ADDED FOR TEST ON TWO LEVELS OF ETOUAH IN F LU E N T ,.1 0 , 50 MG/L BY UT REF BJK NB 7 0 1 8 :5 1 -5 4 -.o m cd X> CC* r---ru r* O'* <3UJ r- x> --i CD I in cr> i--i 70 oom cow 73 TO *T3 i> m to o x* T> --1 om o oo ms o "n oo -n to ~n o 73 O C O X* 22W -H --} I --3 73 m 73 O O H-t o o mo i> r- n 1n-4 rw"0 OW73 4-4 0320 Z 3> CD 2 CD -* (D3 TO H-4 -J I-- HH CD O m O c CD om3ccr>2oo mo r-- \ 03 -* ru to cn <s O <S> Q ^ cd gj RUNDATE 0 3 2 6 8 2 -0 3 2 9 8 2 9288K)00dV RESPIROMETER RUN P V O H - RUNDATE 0 3 2 6 8 2 -0 3 2 9 8 2 REF BJK NB 7 0 1 8 5 5 1 -5 4 * om t-- cr> ru U3 i cn o s> o TO 3 TO <r> m N. O P" --9 m mo "9 O TO t= n> i> --j 3m co i--< z-nz ~on * TO + CO = <S 2> --9 4$ cn M X cm m3 ro o o cn cr> i c-- Xo c; c: G> 70 ** om CO w cr> X> o 33 --1 --3 f-* ID <s> -C 1 S' <s> - cn - i-* <s> - , cn - ro <s> - ru cn - CsO- -- CJ cn - 4*. G> 4^ cn - cn <s - cn cn - (T) <s> ~ ff) cn -j o 7Di\r \ cr>3 CUO i <s> <s> cn s< i i- -i- i <s> cn <s> cn J__I--U-l__111111 IZQ8lOOOdV RESPIROMETER RUN P V O H - RUNDATE 0 3 2 6 8 2 -0 3 2 9 8 2 REF BJK NB 7 0 1 8 :5 1 -5 4 m o co c* n CD I cn o o70 3 70 om *N O rn o 0e= 7j>0 X> --3 xm 1--4 CO x -n -*n oxi CO c <S> Z> CO X <z m ro c? --J h X m 01 CO X i r4 o *+ c: c C> XJ o cn mw co --J -c RUN PVOH GROWTH RATE 3 = .0 1 4 0 9 HR-1 GROUTH RATE 6 = .0 2 3 4 2 HR-1 8Z88(OOOdV I Cell # SEED RESPIROMETER RUN PVOH-2 123456 .......... ERG-SPRINGS MILLS BIOMASS FROM PVOH-I--------- /----washed cells----/ /---unwashed cells--**/ SUBSTRATE Control 250 mg/1 250 mg/1 Control 250 mg/1 250 mg/1 VINOL VINOL VINOL VINOL 205 325 205 325 INITIAL* pH TOC (mg/1) 6.94 13.7 6.90 129 6.90 136 6.88 13.5 6.84 131 6.90 134 FINAL pH TOC TSS VSS %VSS 7.06 12.4 249 211 84.7 6.64 18.7 447 373 83.4 6.83 19.9 409 318 77.8 6.91 13.4 236 204 86.4 6.57 18.5 379 306 80.7 6.79 20.1 373 295 79.1 a(63 hrs) 02 TOC %T0C Red*n 02/TOC 9.2 1.3 9.5 7.07 239 110 85.5 2.17 265 116 85.4 2.28 14.8 .1 .7 146 256 113 85.9 2.27 278 114 85.0 2.44 AA 02 TOC %T0C Red'n 02/T0C 230 109 94.5 2.11 256 115 93.9 2.23 241 113 95,7 2.13 263 114 94.4 2.31 *This run started up with terminal materials from PVOK-1. Prior run made up with BOD nutrients, P04 buffer with NH4C1 to give 28 ppm N per cell in 2,5 and twice that level in 3,6. Previously titrated to pH 7 with H3P04, 20 mg/1 ATU added to inhibit nitrification. Solids data not taken at end of run PVOH-1, hence no individual TSS/TOC nor solids 02 equivalence calculations for either run. Polyvinyl alcohol solutions made up at 1 % by weight by suspension in cold water, warming to dissolution: VINOL 205 VINOL 325 hydrolysis : partial - 88% viscosity : medium full - 98% low 032982-040282 J/j NB 7018:55-61 APOOOf8829 I N> ELECTROLYTIC RESPIROMETER RUN PVOH om3CCD2o ru n\c^3 oo mm r- r* ru *-* ii C CD ru Xm cn m 2 TO \o No C" CD "0 d X3 C t--i CD l-OHH3 rru r- CD --j cn co Hm o 3 CD CD c: CD CELL 3 - -CELL 4 -CELL S -CELL 6 1 U 250 MG/L UT UINOL 325 UNWASHED ERG/SPRINGS P1ILLS BIOMASS 4 U 250 MG/L UT UINOL 205 4 U 250 MG/L UT UINOL 325 RUNDATE 0 3 2 9 8 2 -0 4 O 1 8 2 REF BJK NB 7 0 1 8 *5 5 -6 0 088lOOOdV l88l000dV FOR CONTROL CELL BIOMASS ENDOGENOUS RATE AS ABODE, NUTRIENTS ADDED FOR TEST ON TUO TYPES OF APCI POLYOINYL ALCOHOL 0 250 MG/L o o mm r- r~ r~ r- to 00 to om3cwzoo ru m\ox tnrv p- -* ru O'* t---C X I> LO I -H to I -r Li. ru to j_L TO XI--I to XI mo m tO c o to x XI "D tn - m m x *--i m xi x> o x> - UM t---Hl 3c?> --3 rn --J *--i NtdU* oo o 2m C1 o-n ~n oo xi -n C X ouc> X tn HI tn - ru ru tn wUmwMuuUum N IN* > KM>MMVUgtUWf Um< MU 4* ug tO ~i to m Xmo X-n O m H-I o x tu m u(4 00 o mo (-< x> r* \ O31--H1 m to X ID O Cf-O4 --I tn 02 d--I 2 O to xo tn c Xto 02 I> to OX to X HH tO 3 -e*. tn mX 0>--0 o --J --3 mo r- to tn 2 tn 9(f VI O M li MM t*M wo w> w M a 4* M u tl 4 a u <4 K MW M ( M M tn (4 co ttno mmNMMId+wVWVUbuW0Uim** MMNMmIVd<*9d>> fU<auB**a ELECTROLYTIC RESPIROMETER RUN PVOH 1 ho RUNDATE 0 3 2 9 8 2 -0 4 0 1 8 2 REF BJK NB 7018S 55-G 0 ?88fppo<iy om cd ru H CO \ oo 2o XI ru to cn m <s> o --! sm oo \ r- X) hh m 2 CD o t-- ~n o rsu> xi cn ez - 3> CD <Z 3 --i m 2O O r* cn co c ru c? cno RESPIROMETER RUN P V O H - RUNDATE 0 3 2 9 8 2 -0 4 0 1 8 2 REF BJK NB 7 0 1 8 :5 5 -6 0 88l0004V - <s> - in ID oj <s> oroH <|fl lf) *rir> * oo ru *- 00 Cor fu ro cd 2Z LU -o E-- -3 ID <X CD A Zli. - LO 3 UJ CN LO gl oz _ <5> RESPIROMETER RUN P V O H - -j-r -- in , -- s> in ' GL = o - in z m -- ro UJ c t-H f-- - LO ru - ru . -- LO - - in T1 'i i i i | i i ID in QS<E*-U4 OCU f r-TT I ' j' r 1 FT | I I IT - ro oj ^ <s> co \ \a:o <s> UoJ a 3 LO _i ru to ro A i--3 UJ o 3: z cn hh <x r> 3 Z > 3 LO cl: ru o u. o in z UJ -- E~ z> <r GL --3 \ AO UJ c po <s> Ul LO cl: ru GL oz oo 1 LO in LU o** o t"1 roo RUN PVO H - GROUTH RATE 2 = .0 1 6 8 5 HR-1 GROUTH RATE 3 = .0 1 8 6 5 HR-1 ^3I \ r- s. o tn tn t881000dV RUN PVOH GROUTH RATE 5 -.0 1 8 2 4 HRGROUTH RATE 6 = .0 1 5 6 8 HR- S681p0pdV cn ?88lOOOdV 777* J Z861 *SZ-QZ w r tutt*|n<n **urtpo 90 % 90 > n 2*6-28 82-9.2 Introduction Tho combination of circumstances which found the carcinogenic hazard of vinyl chloride (VC) being dlscovorod at about th# same time as tho clone# of risk analysts was undergoing rapid development, and tha groat caurclal Intarost and long history of use of the substance has resalted In a body of literature and pharmacological data greater than one can expect to have for nest substances. It Is therefore instruc tive to review the many risk assessaents which have been prepared for VC against tha available biological Infereutlon to datarain# If we can evaluate the extrapolation oethods used, end to discuss the current regulations for VC In light of this ceoparisom. Hazards of Vinyl Chloride It is necessary to decide first which of tho hazards presented by VC should be the basis for tho risk estimation. The substance presents the acute hazards of frostbite froe exposure to tho liquid, of anes thesia at concentrations over 8,000 ppm end suffocation at higher concentrations (von Oottlnger, 1955). It also forns explosiva mixtures in air above 3.75 voluee percent, end so the efforts to control the physical safety of operations generally preclude exposure to acutely toxic concentrations. These control efforts ware reinforced In the ntd-1960's where It was discovered (5uciu, 1963) that workers who had been exposed to very high levels of VC developed "vinyl chloride disease," the prinary aanlfestatlon of which was acronsteolyxls (AOL), a degenerative disease of th bene tufts In the hands, and nor* rarely of tho feet and luabar region. Although crippling to sont degree, this disease is not fatal, end Is at least partially reversible If exposure Is ellainated (Granlgtr, Walker and Ward, 1980). Almost ten years later it was found that sene ef the workers having dollar exposure else were developing angiosarcoma ef the liver (ML), a rapidly fatal disease. Oddly enough, then Is only one possible case of a worker developing both AOL and ASL (Stafford, 1981) among the 80-plus cases of AOL end 90-plus cases of ASL new known worldwide, although both art diseases of the vascular system. Several large epldealology studies were conducted on workers exposed to VC (Baxter and fox, 1976; Chiezie, 1980; Duck, Carter and Coonbu, I97S; Equitable Envlromentel Health, 1978; Fox and Collier, 1977; Freatzol-Beyme. Schoitz, and Tbciss, 1978; Theriault and Allord, 1981). and ASL was the only fetal dlseasa found consistently to be In excess In these 2 persons. Anlnal studies have shown an excess ef tuaors at other sites, but the lowest exposures et which these occur are considerably higher than that for ASL. For exaeplt. Hal tool (1979) reported the following data: Site Concentration For Significant Elevation Forestoaach papillomas: Jtouroblastooas: Zyebel gland carelnoeas: Nephroblastomas: Liver angiosarcoma male: female: Hiamsry edenocarclnona: 30.000 ppm 10.000 ppm 10,000 ppm 250 ppa 200 ppm, 50 eg/kg 50 ppm, 16.7 mg/kg 9 ppm The lew concentration for onaot of mammary tumors was of concern when a preliminary study af fabrication employees reported an excess ef breast timers (Chlazze, et el., 1979) bet a followup case-controlled study (Cbiazze, 1980) found no association between the cases and VC exposure. Tho largest study of VC-PVC workers in the United States reported slight excesses of brole and lung timors (Equitable Environ mental Health. 1978), but this was not seen In the other studies referenced above. Tha excess of brain timors was small, and not dosaor exposure-related. The overall txcess ef lung timors resulted free on excess la one plant only, and reexamination ef those coses also showed no association with VC exposure (Waxweller, 1976). Vloyl chloride has been found to be active In several In vitro Mito genetic tests with bacteria and yoasts (Hopkins. 1979) andlt appears to cause ebroeosomt abnormalities In exposed workers, but these changes are reversible when exposure Is reduced (Hansteane, 1978) and several studies ef neighborhoods around FVC plants have felled to shw a supportable association with birth defects (Edeonds, 197S, 1976). It Is not a teratogen In rodent* (Johns, 1977). Therefore It appears reasonable to assime that If there is any signif icant chronic risk other than ASL, It Is considerably smaller than that for ASL, and that an adequate risk assessment can be based on only the liver turners. 82-1 1 ( H0T6 TO EDITORS Under the mow federal copyright law, pubUcmtlen righto to thie paper era retained by tha authors). 3 AP000I8837 favit* pf >1sk Assessments 1. Schntldaman, 1975 4m of the first attempts to utilize animal data to estimate risks at very lew exposures was that of Schneiderman, Mantel and Irown (1975). They used preliminary Haltout results to compare the estimates attained free three possible mathematical models. Thffi99i assurance level of a "safe" dose at e lifetime risk of 10 was estimated from several extrapolation models as follows: Ufl Nobit (slope =1) Logit (slope * 3.45) Legit (slope 2.3, one-hit) 73 ppb 119 ppb 2.1 ppb The authors discussed the recognized difficulties of extending these rat data to humans and of providing animal axparlnents that could answar satisfactorily tho question of human risk at very low dotes. 2. Kuznock end NeGeughy, 1975 The PA was the first group to attempt e human risk assessment for vinyl chloride (Kuzmack and HcCaughy, 1975). This pioneering effort attempted to use both aninel end human data, and to show cooperative results from both the linear end loe-problt models. It concluded that there was an individual risk of 71 x 10 * per ppa of lifetime exposure to VC by the linear extrapolation method, and that the log-problt results wore one-tenth to one-tendredth of that. This effort Is subject to several serious criticisms. The exposure data used for human experience was that from a group with less than average exposure, while tho ASL rate was chosen from only those plants which did report cases, and ignored the remainder of tho population. Thus, their incidence rata ef 7.5% coepares to an actual figure of about 0. IX. They used as their primary nethed a linear extrapolation of rat data, tdilch often has been seen to overestimate the actual rates by at least two orders of magnitude, and they assumed the total cancer ret# to be twice that found for ASL. This same estimate was used by the EPA (1979) to estimate the concentration of VC In drinking water which would produce various levels of risk. These estimates are, of course, subject to the same criticisms. Nisbet (1978) challenged the estimate of Kuzmack and KcGsughy (1975) when It was used by Wilson In testimony before the OSHA hearing on Its generic cancer policy. Nisbet stated that his calculations showed the risk to be 10-30 times greater, by the sane calculation method. Wilson (1978) suggested several flaws 82-4.2 a In the Nisbet procedure, Including the fact that ha chose for his extrapolation one point at 25 ppm from Kaltonl experiment BT-15, and that this point is mot in good agreement with the whole body of data. Further, he Chose to use total cancer incidence in the rats. Including those at zyabal glands, which have no counterpart In humans. Both Wilson and Kuzmack and Mcfiaughy had used a factor of two times ASL to account for possible cancer at other sites. Wilson did acknowledge a mathematical error which made kls results half the proper number. Albert (1978) applied this same general procedure to other poten tially carcinogenic air pollutants In the United States and calculated the expected annual cancer deaths as fellows: Arsenic Somalia Cactoii* Coke ovens vc (aftor regulation) 15.8 77.8 26.2 149.5 1.0 3. fiehrlng, 1979 Gehrlng, et !., (1979) applied an experimentally derived bio transformation correction (Gehrlng, at al.. 1978) to rat data and estimated the Incidence in ImaMns at twe different exposures by eeans of four different extrapolation esdels. Their estimates at 500 and 200 ppm TWA bracket the observed experience for tuaans when derived from the probit and the unconstrained linear models. The 1 inear-through-zero and onm-hit models consistently over estimated the Incidence. Although not considered by the authors, tho linear and probit models match rather closely the total U.S. experience of occupational ASL at an assumed 1,000 ppm exposure. The linear model predicts no incidence below 99 pps*in humans. The prebit model predicts a human risk of 1.5 x 10 * at 1 ppm. Thus, a mechanism for adjusting for tho difference In metabolism betweee animals and humans appears to be useful. A limitation of the Gehrlng procedure is that It usas partial Naltonl data, and tests the results against the CHA epidemiology study. That study was not the "end of the experiment"; it stopped at the and ef 1973, and sevaral deaths have occurred since then. Neither did It caver the entire population, but only tho enployees of those plants which met certain crltarla for data retention and length of operation. The Stafford (1981) data does cover the entire population and extends the history for seven years. The size of the population is not known, but a reasonable estimate, based on normal worker turoover rates and tho number ef plants not included In tho CMA study. Is certainly not less than 25,000. This would give a gross Incidence of about 0.1%. Of these, the number actually exposed to substantial exposures would be about 25-30 par plant at any ont time. Multiplication by 2$ plants, and a factor of three for the turnover during this period, would give about 2,000 highly exposmd persons, for an affective Incl- 82- s AP00018838 deuce of just over IX. Personal experience would Indicate that, for the period prior to 1964, when all of the first exposures of the fatal 26 cases had occurred, the avenge exposures of this highly exposed group certainly Mas in excess of 1,000 ppn for the working day. Malteni (1979) found a IX Incidence at about 1-10 ppe In rats. Calculation of the dose equivalent to a IX Incidence in rats gives 0 ppe by the linear nethod and 7.S ppe froe the log-pratolt aquation for the coeblned Haltoni inhalation experieeats. this crude and subjective estfaata would then say Uwt eea is about 100 tines as resistant as the rat to VC inhala tion, a figure generally In egreeeent with other estleates (HCA8, S2-9.2 4. food Safety Council 1970, 1980 The Food Safety Council has rirnneinrtnl (FSC, 1976} the use of the ganea eulti-hlt nodal because of It* flexibility in handling dosa response data of varying curvilinearlty at low doses. It has calculated (FSC, 1960) the naxieue likely and lower 97.5X Halt doses for substances at various risk levels and with different nodels. For VC, at 10 risk, these results are as fellows (basad on aarly Haltoni data): One-hit Aral taga-Ooll Woibult Hulti-htt 2.0 x 10~| ppe 2.0 x loj ppe 2.! x loT>ppn 3.9 x 10 ,<rppa For this substance, the goodness of fit of the Welbull eodel (0.56) was superior to that of the nultl-hlt (0.32). Neither of the other two nodels gave acceptable fits. This was In part because of the concave shape of the curve, which Included all of the high doses In the dose response data. S. Dow, 197$ A Oow Heath Teae perforeed a relative risk astlnatioa for several coapounds (Longer, et al., 1979) which considered probable exposere, the consequence of exposure, the physical state of the substance during processing, and'the current exposure standards. This resulted in a value of 400 for VC in a "closed systee but * with aapleye** in the vicinity." The sane procedure assigned hazard rating values to soee other substances as follows: benxem, 10; phosgene, 410; hydrogen sulfide, 5; arsine, 9,700; end hls-chloroaethyl ether. 69.706. In a batch operation with occasional Manual handling, the hazard rating for VC inertwed to 9,700 by this Method. 6. hehlr, 1980 tfehlr, et at., (I960) conducted a series of tests for the Consuner Product Safety Coanlssion, a pert of which consisted of exposing rets and nice to a series of short, high exposures, rather than 6 the usual extended low dosage. They included one-hour exposures to rats and nice at 50, 500, 5,000, and 50,000 ppn, 10 and 40 hour exposures at 500 ppn, and 49 and 100 one-hour exposures at SOppb. After lifetime observation they found m affects on rats, or their offspring, nor on nice exposed to less than 500 ppn. Those exposed to over 500 ppn developed pulnenary adenoMs, but they also bad suffered froa pneuaoaltls. They considered the published data on eaiaal exposures and concluded that there was a llfetiee dose below which no oncogenic response Is seee. This was estinated to be 5,000 ppn-hrs for ice and greeter than 50,000 ppn for rats, regardless of whether the dose was attainistered over a short or long period. This concept of equality of effectiveness for all nodes of exposure does not have geaeral acceptance and would not appear to be correct, based oa our present understanding of carcinogenesis. Dose-rate effects arc, of course, well known. However, the degree to which this can be extended to ell types of effects is net known. These authors also used the Crunp-Guess nodal (Cruap, Guess and Deal, 1977) to evaluate their data on nouse pulnonary cancer, and estinated that exposure to 5,000 ppm VC doubles the probability of cancer, while 50,000 ppe increased the risk nine-fold. In view of tho fact that pneunonltls was present In all anlnalt exposed above 500 ppn, it is questionable If this was a direct oncogenic response, or the result of an nongenetlc event because of severe lung danage. Haltoni (1979) also reports an Increase la lung tuaors in nice, but not in rats or banstors. Thus, tho significance of this finding to risk In hunans is questionable. 7. Aadersoa, I960 Anderson, et el., (1960) extended the work of Gehring, et al., (1976 and 1979) to Incorporate the anount of netabollc products fron VC which actually was bound to the ONA of exposed rats, (Gehring and flaw. 1977) rather than the tout anount Metabolized. They assigned various values to the pareneters in a MichaelisHonten aquation depicting the kinetics of the netabollc process, and compared the results fron extrapolation to low doses by log-probU and nultl-hlt nodels. They found that the two extrap olation nodels responded quite differently to these variations at very low deses, and that it was not possible to selact one aode) at the nor* appropriate fron the high-dose data. Use of the values of Gehring for the prlnary paranct*r}7gave estinates of the dose equivalent to llfetla* risks ef 10 of less than 1 ppn for the probit Model and less than Z ppn for the nultistag* nodel, a correspondence which the authors pointed out was better than the precision of Intorspecies conparisaas. 62-9. 7 CO oo ;^ i j j I j I i I ! j I j j > I i 8- EM. I960 TIn final version of iha water quality criteria document for VC (EM. 1980) used a different approach for risk estimation. Tha slopa of tha incldaoca of all tuners at tha lowest doses of Heltenl experlaeat BT-I was adjusted for the fraction of exposure, the equivalent feeding level to give tha sane blood concentration of VC as ty inhalation (saa HIthey and Collins. 1976), and tha ratio of the surface area of hueens vs. rats, to produce an estiaate that a lifetime risk of 10 a would be ceased by drinking 2 1/day of water containing 20 g/1. Thera Is saae confusion in tha aetheaatfes given In the report, and tha assuaptioas on which the adjustaents arc nade are far fron having general acceptance, although generally following NAS recommendations. It appears that this procedure overstates tha risk by several orders of magnitude. 9. NAS, 1980 Tha National header of Science (1977) calculated the upper 95X confidence Halt for risk froa drinking water containing vinyl chloride froa the probabilistic aultlsUge nodal and aar]v Haltoni rat data. They report (NAS. I960) a llfatla* risk of 111* as being equivalent to 3.0818~ ng/kg/day. For a 70 kg person coniualng 2 1/day, this would calculate to on acceptable level of 1 g/1. The difference between the EM end HAS cumbers cones froa tha different curve-fitting Methods far tha aaiaal data. 10. Gaylor and kodell (1980) applied linear "Interpolation" to tha sene early Heltonl data used by the Food.Safety Council (1978) to arrive at a predicted naximm risk of 10 . The ippar 97. SX confidence Halt of tha aaiaal data was taken as one paint on tha interpolattva lino, and zero Incidence at zero exposure as the other. Jbis produced a lower 97.5X confidence Halt dosage of 7.1 x 10 4 ppa for a lifetlne risk of 10 * In rats. The1r_jpp11catlen of the Araitgae-Ooll nultlstege aodel gave $.2 x.10 4 ppn as the dosage et 10 " Iffatiaa risk ceapared to 2 x 10 * by tha Food Safety Council. Tha difference Is due to alternative tittaptlons on the value of the exponential dose tone. 11.. Cruap and Guess (1988) reviewed seae of the earlier risk estlaatos for vinyl chloride la drinking water, and recalculated the risks, using the one-hit and aultlstage nodels. They arrived at an upper 95X confidence Halt of I1fe|iae risk for drinking water containing 1 g/1 of VC of 4 x 10 , based on early Haltoni inhalation data. Using the assueptten that a 0.2X incidence ef ASL ie workers had resulted froa a lifetlne exposure of 70 g/kg, they obtained a aaxlaua ltkeltheod risk of 10 * froa 0.3A g/1 by both the aultlstage and linear nodels, with 9&X lower confidence Halts of the saae risk at 0.24 g/1. These two aodels reduce to a linear fora when used et very low doses and with the assimption f no threshold value. J2-9.2 B These authors cite EM data on the occurrence of vc In public water sugalles which by their nethods yield e Hfetiae risk ef 3.7 x 10 , or 12 deaths per year froa this cause in the United States. None ef these has been observed, despite the accuauletlon ef IS years' data on ASL deaths (Poppar, 1978). 62-5 12. Scott (1981) ascribed tha docraised incidence ef tuaors In rats at the higher doses to a coll killing procass. and adopted the Helbull nodel to account for this. Application of tha nodal to saae early Naltonl data produced a curve which fit tha data free 50-10,000 ppa. He did not attest to extrapolate to doses beyond the experimental range. 13. Cerlborg, 1961, also applied the Weibull aodel to 31 bioassay reports on a variety of aninal carcinogens. He concluded that the one-hit aodel was not appropriate and that carcinogens could bo divided into categories according to the shape of the curve, a.g., concave ar convex. Ha found that the early Naltonl data on VC fell Into tha feraer category. Application of his parameter estlaatos to those data, assuaing no spontaneous Incidence ef ASL, gives 2.S x 10 ppa for a lifetime risk of 10 * for rats. Later calculations Including all of the published Naltonl date did not change the results significantly (personal coaaunicetioa). He found the Welbull shape pereaeter to be approximately 0.5, which is assumed to be the rwaber of stages for tuvor initiation. This Is consistent with the finding by Gehrlng (1977) of s satur able aetabollc path which produces tha proximate carcinogen. It also suggests that the waber of "stages" Is tha nunbar of flalte rete steps before the rato-lialtlng step. There nay be other stages following, but they are not rate controlling. Actually, there appears to be at least two saturable mechanises Involved In the pberaacokinetlcs of VC, the aetabolisa to tha ultiaato carcin ogen and tha detoxification by tulfhydryl groups. 14. One further evaluation af human risk can be node froa the experi ence of parsons residing near VC-PVC plants. The EPA estimated (Xuzaack and McGaughy. 1975) that five nil Hon parsons lived within five alias of those plants, and wart exposed to an annual average concentration of 17 ppb- The present distribution of plants was generally well-established by 1959, thus wa have 22 years af history, or about 110 million person-years. About five r six of these plants, with 1-2 nllllom neighbors, go bock another 20 years, but those data are not fira enough for inclusion. Tha fact that no case of ASL has boon cohflroad as arising from these Mbfent.exposures places the upper bound of risk at lass than 2.7 x 10 ' par ppa-yr. It Is believed that tha exposure data were overestimated by EPA, and thus this result any be too low, but it is in the same general range as that arrived at by Gehrlng (1979) and Anderson (1980) after asking corrections for pharmacokinetics. 9 AP000I8840 Extending this crude calculation, these five elllfoe persons ere now supposed by EPA to be exposed to 0.2 ppb (probably a high figure), which would predict no nore then 0.0003 deaths per year, or one per 3,700 years in that whole population duo to VC exposure. But it also oust be recognized that with approxleately 20 cases per year of ASL In the general population, ttore caa be expected froe a purely statistical basis that there should be one case every two years or so among this grot? of 5 etUlon plant nelglr hors. The results of these estinates discussed above are coopered in Table I, after conversion to e uniform 10 * lifetlao risk. Estimates 5, (Dow . 1879) end 12 (Scott, 1981) were not In a fere to perelt this comparison. See 0SMA, (1980), for references toiler othor estinates that wart not considered here. It can be seen that the results fgll Into two major categories, these tdrich project that the risk of 18 * occurs at exposures of greeter than 1 ppm, and those which find that risk In the ppb range. The estimates which yield the higher allowable exposures ere based on human data (Nos. 3, 7 and 14) or use a log-prebit extrapolation model (Ne. 2, second estimate), or predict threshold (No. 6). The remainder generally are based on the linear, non-threshold aodel, and make no biological correction. The result Is a difference of 3 or 4 orders of nagnitude. The estimates which yield the higher allowable exposures ere in bettor egreament with human experience than are those of the other group. Additional Data All of the extrapolations reported here hove used for the original Naltonl data from his experiment IT-1. He has now reported (Haltool, 1979) three other comparable inhalation experiments on the same strain of rats, and one oe another strain. In addition to two Ingestion studies. The results of these experiments are shown In Figure 1, on e log-protolt scale. It can be seen that they all fellow a sinilar pattern, but that there are large variations in slope between the various date groups. Table III contains the log-probit equations calculated from some of the Individual experiments, and various groups of exporleents. Excellent fits are obtained for a single experiment, es would be expectod from the small number af data points, but adequate fits are obtained for the group as a whole. Inclusion of the historic control data on ASL (0.031 spontaneous incidence) did not effect the fit substantially, except for the very low dost data. Inclusion of the 0,0 (origin) as a data point did give significantly poors* fits. The coabined exporleents Indicate that a lifetime risk ef 10 * for rats Is obtained from a dose In the 1*2 ppb range. Siailar variation Is seen with the ether mathematical expressions, such as linear or exponential equations. 82-9.2 10 8; Regulatory Status The current regulatory status ef vinyl chloride is summarized in Table II. The first retaliatory action on VC was token In 1973 when the Bureau of Tax, Alcohol and Firearms prohibited the use of rigid PVC as liquor containers. This was basad on it being present as an adulterant, and not on any consideration of risk. The Consumer Product Safety Coamission (CFSC), the Food and Drug Atoinistratlen, (FDA), and the EPA all acted to baa the use of VC as an aerosol propellant thus establishing a zero risk position. The FDA proposed (FOA, 1975) to withdrew the prior sanction status of rigid PVC as a food package coaponent because of the concern for residual VC that eight migrate. The FOA has token no further action on this proposal, and now is considering a "constituent11 policy uhleh would permit a lifetime exposure at some fcctptable risk level. This risk has been proposed recently to be 10 * lifetiee for the gluttonous consueer. As was discussed above, the EPA required a best available technology approach which reduces the overage exposure to those within S alles of a plant to about 0.2 ppb, by EPA estimates. OSHA established a rule in 1974 which set 1 ppm for 8 hours es the maximum permissible exposure, and also set 0.5 ppm as an action leva! below which most features of the regulation did not 1y. These were chosen as feasible levels, and not necessarily "safe* doses (OSHA, 1974; EPA, 1976). The EPA has established on exposure to the general population only 0. IX of that allowed In the workplace. The CPSC has required zero exposure, end the FOA has considered that approach. Depending on which method of estimation the FDA may choose. Its allowable exposure could be either greater or less than those currently set by EPA and OSHA. It has been estimated that the maximum amount of VC ingested by the average European, who uses much more plastic packaging than we. Is lejs than 2*. g/day, (CEFIC, 1976) which would be In the order of a 10 * er 10 lifetime rich by even the most conservative models. There have beam various estimates eade ef the cost-effectiveness of the Federal regulation for vinyl chloride. Graham and Vaupel (1981) estimated that the OSHA nil# cost 97.5 million per life saved, and 6490 thousand per life-year saved ever the option of leaving the exposure limit at SO ppm. Luton and Hiller (1981) state that the inputed value of e life free the OSHA standard Is $4 million. Morrell (1982) uses am annual cost of 320 million and an annual benefit of 0.1 life saved to derive e cest/beneflt of 3200 million per life for the OSHA rule. The EPA has reported (EPA, 1979) that the cost of compli ance with Its VC standard was 3296 million through July 7, 1981, and will be am additional 3478 million during the next five years, all In 1977 dollars. If the EPA estimate of up to 20 deelths per year were correct, this would be e cost ef 34.7 ellliom per life. However, as discussed here, there Is no evidence that any lives have beet saved by this rule. There are many difficulties in obtaining accurate estimates of this type, and serious problem In determining the proper value to be assigned to a life, nevertheless, the doubtful nature of the dales 11 APOOOf8841 for any significant benefit free these rules suggests that at best, these regulations are excessively cestly to society. Therefore, we must attoept to laprove both oer date base end our aethods for inter preting and applying the data. Discussion kbit cu be learned fro* this exercise other than the already recognized fact that various extrapolation aodels can yield very different results? In this case, at least, there are savers! points which sr worth considering. 1. Vinyl chloride Is no exception to the rule that bunoa data always nest be incorporated whenever possible. The epidenlc of occipatlocally induced ASt which was feared in 1974 has not naterialized, probably due to the steps that were taken in the early 1960's to reduce exposure because of the discovery of ML. No instances of A$L froa exposure to VC in the general population have been substantiated. The overprediction of occupational cases was due te the underestination of worker exposure and overreliance en raw eniaal data without proper pharmacokinetic adjustment. We are net now able to extrapolate reliably between sinilar species and certainly not frow rodents to humans, without nuch additional data. 2. The regulations for vinyl chloride were not based prinarily on scientific data, but on socioeconomic and political decisions. This is no surprise (Crandall and Lave, 1981), but is a fact which should be acknowledged openly, along with the understanding that this position will continue to penalize good science. 3. Mathematical extrapolation models are not adequate in thenselves for predictions of risks nuch beyond the experimental range, no natter how good the fit is to the data in the observed range. The variability of relatively small experimental groups adds to the error range. Thus, bioassays Intended for quantitative risk assessment applications should be at as low doses as possible, and as Urge as possible, and should be Interpreted very cau tiously. 4. The current state of the art is such that quantitative risk assessment* may be useful for determining relative risks from sinllarly acting carcinogens, but are not suitable for acrossthe-board application to all mechanisms of carcinogenesis. Ihts Is not to say that we should abandon efforts at developing ore effective risk assessment methods. He must, however, recognize the problems Inherent in blind application of mathematical aodels without proper assessment of the available biochemical data, or an understanding of how applicable the experimental data are to Inmans. 82-9.2 12 He have available tomit least as nuch data regarding vinyl chloride . as we have for any ether substance, and we still have difficulty in deriving a suitable exprtsslea for risk from a purely mathematical or statistical basis. Only when human relevance is considered can we arrive at a prediction that approximates actual experience. The regulators are faced with a tremendously difficult task when they are presented with a few pieces of animal data which suggest the need for concern end potential regulation. He oust develop a suitable program to obtain and use as much relevant data as possible to assure that rational regulations are possible. The vinyl chloride experience can help us understand the kind of data which are needed. 378S-A1 2/19/82 lb* KtftfWCH Albert, R. E., letter te R. S. Noveen, EPA, "Ceapar1son of vinyl chloride carcinogenic risks with risk from other pollutants", Washington, DC, 16 June 1978. Andersen, M. W.t et el., Tox. AdpI. Han. 55. 154 (I960). Baxter, R. J., end A. J. Fox. Lancet. 1976 245. Corlherg, F. W., Fdj. Osnet. Tex. 19 2SS (1901). CEF1C Connlttee for the Toxicity ef Vinyl Chloride. "Vinyl Chloride Toxicity end the use of PVC for Packaging Foodstuffs," Brussels, Foh. 1976. Chlaxxe, L., Jj. Occue. Med. 22 (10) 677 (I960). Chlazze, L., Jr.. W. . Michels, and 0. Hong. i. Occup. Hejt., 19 623 (1977). Crandall, R. V., and L. Lave, "The Scientific Basis of Health and Safety Regulations," Brookings Institution, Washington, 1981. Crtap, K, S., and H. A. Guess, "Orlnklng Hater and Cancer", PS81-128167, Dncaeher, 1980. Crunp, K. S., H. A. Guess, and A. L. Dnal. BionetHcs. 33 4370451 (1977). Duck, B. H,, J. T. Carter, and E. J. Coenbes, Lancet 1975 11, 1197. Ednends, L.. "Birth Defects and Vinyl Chloride", Proc,. Conference on Wooes and the Workplace. Washlnaton. DC. 1976, alsoTeratology. 17 137 limy.----------------------- -- Ednends, L. 0., H. Falk and J. E. Nlssla, The Lancet 19 1098. Environmental Protectlnn Agency, Standard for Vinyl Chloride, 41 Fed. tela. 46,560 (1976). Environedtal Protection Agency "Vinyl Chloride, Aableat Water Quality Criteria", PB-292446, Washington, DC, 1979. Envireanantal Protection Agency "Anhlant Water Quality Criteria far Vinyl Chleridn," EPA 440/5-00-078, October, 1980. Envfrnonental Protection Agency "The Cost ef Clean Air and Clean Water", Annual Report to the Congress, Deceaber, 1979b. Senate Doctamt He. 96-30. tl.S. Government Printing Offlcn, WashiagUn, DC. 02-9.2 14 Eguitable Environmental Health, Inc., "Epidaniologlcal Study ef Vinyl . Chloride Workers, Final Report". Prepared for Nanifacturlng Chenists Assoc., Washington, DC, January, 1978. Food and Drug Administration, Notice of proposed rulaoakfng, 40 Fed. Beg.. 46,529 (1975). ------ Feed Safety Council Final Report "Proposed Systan for Food Safety Assessment", Washington, OC, June, 1960. Food Safety Council, Scientific Conalttee "Proposed Systen for Food Safety Assessnont." Food and Cosnet. Tex. 16 St^pl. 2 1978. Fax, A. J., and P. F. Collier, Br^ J^ Indj. Wed. 34 1 (1977). FrantMl-iew, R.. T. ScMb. and A. M. Tkless. Art. Socialwd Prevent.. U 218 (1978). ------ -- Gaylor, 0. W.. and R. L. Kodell. R. L.. J. Environ. Pathol. Tox. 4 3RS (1960). ----------------- ----------------------- Gahrlng, P. J., and 6. E. Blau, J^ Environ. Pathol. Toxicol. 1 163 82- GehHm, P. J., P. G. Watanabe. and C. H. Park. Tox. and Aool. Phan. 49 15 (1979). ------------ ------------------- Gahrlng, P. J., at al., Taju Aool. Pharmacol. 44 SOI (1976). Grahan, J. 0., and J. W. Vaupal, Risk Analysis 1 B9 (1981). Granigar, R. G., A. E. Walker, and A. N. Ward "Vinyl Chloride Hoaoaer-lnduced Disease: Clinical, Radiological and lanunological Aspects." Chapter 11 in "Induced Disease; Drug, Irradiation, Occupation", L. Progar, od., Gruno and Stratton, London, 1900. Haasteeoe, l.-L., ot al., Mut^ Res. 78 211 (1978). Hehlr, R. N., ot el., "Toxicology, Carcinogenicity and Reproductive Effects of Single and Multiple Exposures to Vinyl Chloride in Rats and Nice", Pro-publication draft. Fab. 6, I960, U.S. Consuwr Product Safety Ceonissloo, Washington, OC. Hopkins, J., Fdj. Cosnet. lexical.. W 542 (1979). John, J. A., ot al.. Tox. and ApdI. Pharmacol. 39 497 (1977). Koznack, A. H., and R. E. NcGaughy, "Quantitative Risk Assessnant for Coenunity Exposure to Vinyl Chloride", II.S. EPA, Washington, DC, Oecorter S, 1975. Laagar, R. R., S. K. Horwood, G. E. Socha, and H. R. Hoyle, Ibis * (12) 1039 (1979). Jnd^ 15 APOOOf884J jken, R.H., and &. C. Miller, J. Air PoL Contra1 Assoc, 31 1254 1961). iltonl. C., 6. Ufamine, A. eiltbertl, 6. Cottl, and 0. Carrettl, Mnyl Chloride Carcinogenicity Btoassays, (B T Project) u an tperlmentel Model far Risk Identification and Assessment In nironoental and Occupations! Carcinogenesis" Presented at "le Club i Cancerogenese Chfalqut", Institute Curie, Paris, Mov. 10, 1979. itlonal Academy of Science, "Drinking Mater and Health", National admey Press, 1977. ttlonal Academy of Science, "Drinking Mater and Health", Vol. 3, p. I, National Academy Press, 1960. itlonal Cancer Advisory Board, "The Relation of Bioassay Dose to the >sessment of the Risk of Carcinogens for Humans under Conditions of w Exposure", Subcommittee on Environmental Carcinogenesis, Draft of 179, citing data from Hesclson and Russell, 1979. isbet, I.C.T., Post-hearing statement to OSHA docket 090, September i. 1976. relational Safety and Health Adnlnistratlon, Standard for Exposure i Vinyl Chloride, 39 Fed^ Jtejfc. 35,890 (1974). ipper, K. at al., Aoj, ^ Pathol. 92 349 (1978). :hne1darman, H. A., N. Mantel, and C. C. Brown, Ann. NY Acad. Scl.. \6 237 (1975). :ott, B. R., Bull. Mathematical Biology, In press, 1981. rafford,. J., private coomunication (1981). Klu, J., J. Orejman, and M. Valaskai, Med. Intern. 15 967 (1963). teriault, C.. and P. Allard. jL Dccuo. Med.. 23 (10) 671 (19B1). in Oettingen, M. F., Public Health Service Pidillcatlon Me. 414, U.S. yiartment of Health, Education and Welfare, Washington, DC, 19SS. imeller, I.. at al.. "An Epidemiological Investigation of an Excess mg Cancer Risk In a Synthetic Chemicals Plant", Presentad at the taeteenth International Congress fsr Occi^atlonal Health, Dubrovnik, igo., Sept., 1978. Ison, R. "Response to comwnts of I. C. Nlsbot," Post-bearing record HA Docket 090, 197B. ithey, 3. B., and B. T. Collins, 3. Tox. tnvir. Health. 2 311 (1976). 62-9.2 16 FIGURE 1 GRAPHICAL REPRESENTATION OF TABLE III LOG-PROBIT PLOT LCC6MP (NHALATK* BT-1 0 T-2 Mb rr-a a sr-is -Q- INGESTION: BT-11 - T 27 I I 17 AP00018844 TABLE I SUMMARY OF QUANTITATIVE RISK ASSESSMENTS FOR VC 92-9.2 ESTIMATE NO. AUTHOR 1 SCHNEIOERMAN, 1875 2 KU5MACK fcMcGAUGHY, 1878 a GEHR1NG, 1875 BASE SPECIES EXPOSURE FOR Iff* LIFETIME RISK RAT RAT. HUMAN RAT. HUMAN rep* 119p* 2ff* Up* 140-1480 p* >1 ppm 4 FOOO SAFETY COUNCIL. 1880 RAT 2X10* p* HEHtR,1880 RAT. MOUSE THRESHOLDS SEEN IN ROTH SPECIES 7 ANDERSON. 1880 RAT. HUMAN >1 PP 1 ETA. 1880 RAT 4 JlG/DAY NAS. 1880 RAT 3X Iff# MG/KG/DAY 10 GAYLOR 5 KOOELL. 1800 RAT D7 ppb 11 CRUMP GUESS, 1880 HUMAN 08 p* 0.7pGAMY 13 CAALBORG, 1881 14 THIS FARES RAT RAT HUMAN aijiG/OAY ZSXI0*p* >1 ppm COMMENTS LOG-PROMT LOGITSLOPE-3.45 LOGITSLOPE T3.1-HIT UNEAR THROUGH ZERO LOG-PROBIT BtOTRANSFORMAL DATA AND LINEAR OR LOG-PROBIT WEIBULL DNA BIN0IN9 FOOO OR WATER WATER UPPER 87.BK CONFIDENCE LIMIT OF LINEAR MOOCL ARMITAGE-OOLL MODEL APPLYING WORKER DATA TO WATER. UPPER 86* CONFIDENCE UNITS WIERULL NEGATIVE EPIDEMIOLOGY 18 TABLE II REGULATORY STATUS OF VINYL CHLORIDE APOOO18845 > 0 o 111 CD o _l z UJ fftf r o > UI ui UI oo H UI LU _J < _J CD - >* z o z m <i (A < X< a. oc O U1 CO 1- O _J _i 3 X a. o < V i/J ec O AC ui N cc W a z* ooo~c < > < hCO UI co UI u. Ui UI 5 o -1 O 3 0 z Ui LJ o 0 o a to d f- O m UI DC >o Ui 3 a a 13 UJ -J CO < acc. 3 a: o UI < o. 2 3 a (O z o 2o u. o OQ z S sXI 3 2 CN X o< >2 _> UJ F< 2 CC UI ocr H Z Q UI Z Z o UI z z IO ste ill UI V o cc n x -* z E2 Of-- O < < <03 O. GO u CO CD 30 < - < >a z UJ 0 u. H < (o/) a. <a < CO U u. < <X CL CO UI O TABLE III EQUATIONS FOR CURVES FITTED TO VARIOUS SINGLE AND COMBINED MALTONI EXPERIMENTS EXPERIMENT rr-i PLUS CONTROLS BT-2 PLUS CONTROLS BT-15 PLUSCONTROLS ALL INHALATION STUDIES (41 PLUS CONTROLS ALL INGESTION STUDIES (2) PLUS CONTROLS ALL STUDIES (61 PLUS CONTROLS ALL STUDIES; LOW DOSES ONLV PLUS CONTROLS LINEAR V*lIK + b br 0.26 0.27 3.05 1.52 6.6 5.28 0.26 0.27 1.75 1.74 0.26 0.29 3.36 2.47 8.59 1.13 -1.06 0.30 3.07 2.80 0.15 0.20 3.60 3.41 0.07 0.07 id 0.88 1.0 0.68 0.61 0.61 0.05 0.06 0.73 0.72 1.03 0.07 0.76 LOO PROSIT P-i IN DOSE * b * br 0.35 2.76 0.66 CONCENTRATION AT 10*6 RISK. ILOO-PROBITV 0.03 1.60 0.88 ID 23 0.66 3.48 ID 0.34 0.27 2.68 0.62 0.002 0.30 3.22 0.68 0.002 0.27 3.0S 0.82 0.001 0.51 243 0.76 0,17 2.71 040 0.42 0.0002 J Z*6-Z8 APOOOI8846 Update on Regulatory Status EPA Vinyl chloride standard revisions under discussion with SPI. 0MB approved change to semiannual reports. Additional suits filed and Sec. 114 letters sent on emergency emissions. PMN exemption policy excludes VCv etc. Study of emissions, including VC underway In Harris Co. Texas. Superfund reporting limits in revision, YC may stay at 1 lb. Revised Test Methods 106 and 107 published 7 and 8 September. OSHA Comment period 1$ closed on proposal to reopen the cancer policy - action next year? Comment period closed on revision of medical record retention rule. Labeling rule not expected until mid-83. Noise standard generally In effect. Respirator rule conment period over, VC Training Film now available from National Audiovisual Center. Voluntary programs now in pilot phase. FDA Promised action on 1975 PVC proposal this October. Constituent policy comment period closed. No action on plasticizers - more tests. Others Unpublished report suggest tumors from VAc exposure. Peroxides cause skin tumors In an 8[el report. TCE bioassay being reviewed this month. States Many have cwn labeling, wastes, etc. rules. AP00018847