Document 8Xm79oj5wgBQvLJvnRZBe1ay

GERMAN Literature on VC/PVC: MEASURES FOR HEALTH 2/24/75 ________________________________________ PROTECTION copies to (with TO/FROM note): ^^ Mr. R. C. Andrews Manager, Safety & Environmental Affairs Union Carbide Corporation 75 Stylon Road Wayne, New Jersey 07470 Mr. Wayne T. Brooks Director, Occupational Safety & Health Services Organization Resources Counselors, Inc, 1625 I Street, N.W. Washington, D. C. 20006 Mr. T. W. Carmody Mr. J. L. Carvajal NY O'-21 514/ 82-3 Dr. Carl U. Dernehl NY0-4 Mr. M, E. Eisenhour Dr. D. H. Glenn Mr. R. E. Graebert 515/ 88 515/ 2 511/ 2000-3421 Mr. Don Guyette Union Carbide Corporation P. O. Box 698 Ottawa, Illinois 61350 Dr. R. W. Holland, Jr. Mr. H. V. Hooper, Jr. Dr. E. Q. Hull Dr. W. R. Manning Mr. R. W. Martin 514/ 4 514/ 82-1 511/ 2000-3428 511/ 2000-3311 511/ 2000-4428 Mr. W. D. Neal 312/ 51 _ Dr. A. B. Steele Dr. T. T. Szabo NYO -28 NYO -32 Mr. J. W. Whittlesey Mr. J. L. Worstell NYO-46 514/ 406-2 ucc 031559 THE SOCIETY OF THE PLASTICS INDUSTRY. INC. 250 PARK AVENUE NEW YORK. NEW YORK 10017 12/573-9400 January 17, 1975 TO: Members of the VCM/PVC Producers Group SUBJECT: German Literature on VC/PVC: MEASURES FOR HEAL1H PROTECTION Attached Is a copy of a translation made available through the courtesy of Air Products and Chanlcals, Inc. This Is the literature that Dr. Ross Adams discussed at the December 6th meeting of the VCM/PVC Producers Group. It appears to give an up to date status on the German knowledge of this problem. Respectfully, JHL:Jo Attachment John R. Lawrence Director of Technical Liaison ucc 031560 VC/PVC: MEASURES FOR HEALTH PROTECTION Published By: German Society of Plastics Industry (VUE) 6 Frankfurt/Main Karlstrasse 21 Tclcnhane f06111 23 78 07/17 I ucc 031561 TABLE OF CONTENTS PVC-PRODUCTION Consumption Polymerization of VC WORK RELATED MEDICAL PROBLEMS Maximum Concentration at the Place of Work First Indications of Cancer Threat Cases of Illness In West Germany Research Studies Emergency Measures Suspension of the MAK-Value Technical Standard Concentration for VC RESIDUAL VC IN PVC Time Relationship Path of Diffusion Temperature Relationship HEALTH PROTECTION IN PROCESSING AREAS Storing - Mixing - Extruding Injection Molding - Calendering - Paste Processing VC CONTENT IN THE FINISHED PROOUCT METHODS FOR THE MEASUREMENT OF VC Drager Capillary - FID-Method Ionoflux-Instruments - Ultrared Instruments Gas Chromatography - Sailing VC-REDUCTION Present Reference Values Future Considerations THIS IS PVC Manufacturing Properties Page 2 4 12 17 * 21 25 29 33 ucc 031562 Vinyl Chloride (VC) Is feedstock for one of the most frequently used and most versatile plastic materials. Polyvinyl Chloride (PVC). Recent scientific findings lead to the suspicion, that VC gas In certain concentrations has a carcinogenic effect. Knowledge and suspicions which In this connection have been accumulated over approximately 1 year are news tcjsclence as well as regulatory authorities and the Industry worldwide. This pamphlet attempts to explain the present state of knowledge and findings. In addition we would like to point out directions for safety measures which have to be followed In the plastics Industry. It Is possible that new evidences have been accumulated since this pamphlet has. gone to printing. * Waiting for these, however, Is not feasible. We are primarily concerned to convey the understanding of this problem not only to the PVC processing Industry but to larger areas of the public. Dated: Frankfurt/November 12, 1974 -1- ucc 031563 PVC-PRODUCTION PVC has been manufactured In the Federal Republic for over 30 years. Consumption Production for 1973 was 1(034t000 metric tons with a value of approximately 1 BillIon(German marks)DM. PVC Is used In almost all areas of the econony whereby primary Industries such as the construction business, electrical Industry and the automotive Industry ere particularly heavily dependent on this plastic material. PVC-Consumptlon 1973 Pipe and Fittings Flooring Cable Installations Films (Flexible and Rigid) Profiles,Including Windows Coated Fabrics (Artificial Leather) Venetian Blinds, Building Tiles, Fascia Bottles Ribbons, Strings, Ropes Hose Records, Shoes, Driving Belts, Conveyor Belts, Foam Materials Total % 23 10 11 22 9 4 6 2 2 2 9 100 ucc 031564 Polymerization of VC PVC Is commercially manufactured In the Federal Republic by three different methods: Emulslons-Polymerlzatlon Suspensions-Polymerization Buik-Polymerlzatlon Polymerization of Vinyl Chloride to Polyvinyl Chloride Is conducted at tempera tures between 40 and 80C at a VC vapor pressure of approximately 6 to 14 atmospheres. At atmospheric pressure.Vinyl Chloride has a boiling point of minus 13C and during polymerlzatlon^ls dissolved In significant amounts In the produced PVC Vihese dissolved quantities are converted Into PVC to a large degree,as the polymerization process progresses. The speed of any chemical reaction depends on the concentration of the used raw materials. Consequently polymerization of VC to PVC Is slowed toward the end of the reaction since the concentration of the monomeric VC In the reaction mixture Is constantly decreased. Theoretically It would take forever to await polymerization of the residual VC. Hence the reaction Is stopped depending on the process used, after approximately 90S of the VC has been polymerized. The point In time at which the reaction Is stopped Is essential for the properties which are desired and necessary for further processing. In all processes termination Is achieved by evacuation of the residual VC gas from the autoclave. It Is recovered by llqulfactlon and Is recycled to the production process. ucc -3- 031565 Economic reasons dictate a recovery as complete as possible since It Is sub stantially more difficult to recover VC gas which escapes during further processing steps such as drying* classifying and movement wfthln the plant. In spite of a massive amount of technical efforts* the removal of VC gas as present In small amounts In PVC particles has been unsuccessful to date. This Is difficult to conprehend In recognition of the fact that Vinyl Chloride bolls at minus 13C and Is temporarily exposed to temperatures up to 250C ^understood to bey during the drying process. The reason for this Is 'V as follows: The liberation of monomer which Is dissolved In PVC occurs on the surface of V(m1grates)7 the Individual PVC particle, on to which It dlffusesjfroci the Inside. This diffusion process Is defined by the drop In concentration toward the surface, the length of the diffusion path and above all by the temperature. WORK RELATED MEDICAL PROBLEMS (as early as the 1930`s when thej A narcotic effect upon Inhalation of VC had been recognized $ large scale use of VC had reached significant proportions. Not until the beginning of the 1960's did scientists discover diseases such as acroosteolysls, scleroderma and liver diseases. Maximum Concentration At the Place of Work A coomlttee of the German Research Association (DFG) specifies maximum exposure levels (MAK) for purposes of health protection In production operations for VC as well as for many other chemicals. ucc 031586 -4*  In 1966 a MAK value of 500 ppm had been specified In Germany. The comnlttee for testing of hazardous materials of the German Research Association defines the MAK value as the concentration of a gas, vapor or particle suspended In air at the place of work, whlch.based on present knowledge,does not Impair the health of the worker under repetitive and long lasting exposure usually vper7 8 hours per day, however, not to exceed 45 hours* average work week. Studies by the American professor T. R. Torkelson ^, led to the reduction of the HAK value to 100 ppm after he discovered hlstopathologlcal liver alterations In his animal tests with rats exposed to 200 ppm during a period of 6 months. Yet the reference book "Chemistry and Toxicology of Plastic Materials" explained as late as 1970: "Vinyl Chloride Is a gas with relatively low toxicity. In higher concentrations It has a slightly anesthetic effect and causes Irritation of the eyes." First Indications of Cancer Threat ^evidence; ' Investigations known until then had not produced any " ^ of a possible cancer threat by Vinyl Chloride. The connection between Vinyl Chloride and a cancer vas recentlyy I xhasv threat ^ treated Infrequent discussions,* been documented In studies by Professor Viola ^ for the first time In 1970. His tests with rats ywerey however,^conducted at unrealistically high doses, which up to 30,000 ppm bordered on the explosion limit of a VC/air mixture.1 2 1) American Industrial Hygiene Association, Journal Volume 22, Page 354 2) Presentation, 10th International Cancer Congress, 22-29 of Hay 1970, Houston, Texas -5- uee 031567 Professor Maltonl of the Oncological Institute* Bologna* Italy was commissioned an by International group of companies to explore In depth the effects of YC under actual operating conditions. Preliminary reports Issued In the sunmer of 1974 show that rats which had been exposed up to 1 year to a range of VC yfrom j concentrations * more than 200 to as low as 50 ppm. have contracted angiosarcoma of the liver* a special cancer of the liver. *R1n-Test> In the U.S. y Laboratories In North Brook* Illinois detected almost simultaneously the same liver damages In mice after 7 months exposure to 50 ppm VC. As an emergency measure the use of VC as propellant In aersol sprays was prohibited In the United States and stopped In West Germany. Cases of Illness In West Germany Professor G. Veltman of the University Clinic for Skin Diseases* Bonn* West Germany had previously determined the danger of VC to the human body on workers which had been employed In PVC production. As a result In recognition of loportant discoveries In the area of Industrial medicine and worker protection* he and his co-workers received the Franz Koelsch Reward ^Manufacturers Association^ donated by the Tp2 of the Chemical Industry* Through the end of August 1974 a total of 124 suspected cases of the *so- calledTcrfsease" had been reported by a few PVC producers In the Federal \Soc1al Security/ Republic^ ^ Insurance carriers have recognized 43 of these cases as occupational diseases. ^definition,/ The medical " ^ of these 43 recognized cases are primarily specified as Raynaud's Syndrome* liver and spleen damages* thrombocytolysls and retlculocytosls. ucc 031568 41 of the afflicted persons have In the meantime resumed employment. Professor Veltman's studies revealed that,1n the severe cases a change had been diagnosed In lung, liver, spleen, skin and vascular systems. Hls.as well as simultaneously publicized studies In other countries gave the signal for a retroactive Investigation of the causes for the death of workers previously enployed In VC and PVC production. Three cases of. hemangloendothellosarcoma IhayeV of the liver, a very rarne case of cancer, V been diagnosed In this connection In the Federal Republic: A worker,who died at the age of 38 and who was employed from 1956 through 1968 e.g. 12 years In a PVC production plant, last as polymerlzer scrubber. A chemical worker who who died at the age of 39. lhad been employedJ for 11 yearskln a PVC producing plant and An operator who was employed In the filling of aerosol spray cans In which VC had been added as a propellant. He had been exposed to VC a minimum of Enlargement of the spleenJ 14 years and died at the age of 43. A. liver fibrosis with"" ^ and esophageal varlcosls had been diagnosed during his lifetime. Vbetween thesej Studies to determine the extent of correlation 'F Heaths and VC In these plants are still under Investigation. Hence It Is too early to finalize a conclusion on the extent of the existence of this disease. The examination of the causes for death are rendered more difficult as a post diagnosis does not lead to reliable results, and *s to date angiosarcoma has been found only after more then 10 years exposure. ucc 031569 -7- Research Studies In addition,to date there Is no unequivocal proof that the occurred symptoms of lexcluslvelyj disease can be attrlbuted^to the Influence of VC. In view of this the Ministry for Work and Social Order has commissioned a research project UmpurltlesJ to clarify If process related 4^ In VC could be considered as cause for the disease. ibelngy Further research projects for the elucidation of the VC disease are+conducted Ithej In cooperation betweentProfess1onal Trade Organization of the Chemical Industry, the Federal Ministry for Work and Social Order and the State Government of Nordrhein-Westfalen. Participants are: Professor Or. Henschler, Institute for Toxicology and Pharmacology, University of WUrzburg, Professor Or. Lehnert, Central Institute for Industrial Medicine, University Hamburg, UndustryJ and the State Physician for-Tor Nordrhein-Westfalen, Dr. Relnl, Ousseldorf. In particular these studies Include the effects of VC on the human organism (Investigations of metabolism), the compilation of a literature survey and evaluations^ well as epidemiological Investigations (determination of Illness /lby differentiated group comparison),/ risk factors '4'" The Central Institute for Ifood Research/ In Zelst, Holland was commissioned by the Society of the Plastics Industry and PVC producers In Holland to conduct a 90 day feed test to deter mine the oral toxicity of VC In rats with ratios of 0, 30, 100 and 300 mg VCper kilogram body weight. At a ratio of 30 mg VC per kilogram body weight, these studies resulted In a "dosage without effects". 100*and 300 mg VC Vresult inJ per kilogram did not ^"concentrations with direct toxic effects." Further Information Is expected as a result of a follow-up 2 year test for the determination of objectionable VC concentrations. ucc 031570 -8* Emergency Measures After recognition of these problems It Mould have been Irresponsible to await results from further long term studies. Emergency measures for the reduction of risk at the place of work In PVC producing plants where hence applied as deemed necessary. This 1$ reported In Document 7/1627 of the House of Representatives by the State Secretary of the Ministry for Work and Social Order on January 29, 1974 In response to an Inquiry by a State Representative. Guidelines for safety measures to prevent Injuries due to handling a Vinyl Chloride were significantly tighten In April 1974 In cooperation between the Trade Union of the Chemical Industry and specialist. the plastics producing industry. Addltlonallyvcontlnuous observations of employees were Introduced In cooperation tfromj between Trade Union and experts A/ the Industry In Industrial medicine over and above the ongoing preventive medical examinations. They are documented In the July 1974 Issue of "Principles for Preventive Industrial Medical Examinations" by the Trade Union. Suspension of the MAK Value A reduction of the established MAK values has been Investigated In connection with the Introduction of a variety of measures. In this connection the Comnlsslon for the Investigation of Health Hazardous Materials had to consider, that the handling of potentially carcinogenic materials require special safety measures and precautions In health protection. Such materials have ipubllshedj therefore for some time been eliminated from thetlist of MAK values and have been reported separately. VC has been added to the list of carcinogenic ithey materials In view of the results fromjanlmal experiments and the experienced ucc 031571 -9- cases of Illness. The previously established MAK value was suspended. The Commission for the Investigation of Health Hazardous Materials Issued a related statement dated June 14, 1974: VpotentlallyJ "The handling of proven or carcinogenic materials requires special precautions and measures for health protection. Hence these are Specifically enumerated and classified as those which a) can cause severe tumors as experienced In human beings b) so far have only been Investigated by animal tests under cond1tion$,wh1ch are comparable to possible exposure of hunan beings In the work process and which In the opinion of the Connrisslon have definitely proven to be carcinogenic: e.g. Vinyl Chloride ^containing; ^amounts of) Iwasi Vinyl Chloride only minor^impurities definitely carcinogenic by animal tests. A special type of liver tumor (hemangloendothellosarcoma) has been observed with workers which had been exposed to high Vinyl Chloride concentrations In specific work locations In the PVC producing Industry. A causal correlation Is 1mn1nent,at this stage, however, nonproven. It remains to be seen whether the recently Introduced In depth toxicological Investigations as well as the retrospective stipulations with regards to employees' contact with Vinyl Chloride confirm or Invalidate this relationship." ucc -10- 031572 Technical Standard Concentration for VC A so called "Technical Standard Concentration (TRK),M akin to that established for benzene. Is to be established following the suspension of the MAK value by a Committee for Dangerous Materials (AgA) organized by the Ministry for Work and Social Order which Is composed of representative experts from trade union and Industry. This standard Is defined as follows: "Compliance with the Technical Standard Concentration at the place of work should reduce the risk of a health hazard, Is however unable to completely eliminate this risk. The Technical Standard Concentration Is based on technical circumstances and possibilities of the technical prophylaxis Un conjunction withy ^ work related medical experiences In handling dangerous materials. Compliance with the Technical Standard Concentration does not completely eliminate the risk of Impairment of health; hence by continuing Improvements of the technical circumstances and the technical Ifor protection.) measures Vconcentrations have to be aspired which fall as far below .the Tech nical Standard Concentration as possible." ^ Up until the suspension of the MAK value for VC. according to a release by the Federal Ministry for Work and Social Order of May 22, 1974, a 50 ppm ^adopted] level was + as recoumended by the Trade Union of the Chemical Industy. The soon to be released Technical Standard Concentration Is expected to be lower. The continuous analytical monitoring of such low VC concentrations Vplace atmospherej In the work^ Is expensive. Hence It Is Imperative that producers and ^processors! kwlthj 5 of PVC familiarize themselvestand work toward Integration of the expected parameters. 1) Work Protection Issue #5/1974, Page 170 -11- uec 03157 A program of regular medical examinations of the employees Is already self* \theseJ evident. The work safety law requires ^ for all Industrial areas starting January 1, 1975. RESIDUAL VC IN PVC Polymerized PVC contains a residual amount of VC based on production related technical parameters as explained above. Depending on Its viscosity, particle Vs1ze7 size and part1credistribution,as well as ambient temperature this residual VC migrates to varying degrees to the ambient atmosphere. An exponentially declining curve results If the residual VC contents are plotted over time. This Vjrlth porous 7 curve has a steeper slope than with dense products and Its slope Increases also with Increasing temperatures. The possibility for the lowering of the residual amount of VC In PVC are defined by-time, - path of diffusion, Time Relationship - temperature. (customary allowance) (diffusionj The hereto $ for gas 3/ would have to be extended significantly to days or even weeks - In order to achieve a significant reduction in the residual VC content. An extended residence time In dryers or tiegassing equipment \.used 7 under presently temperature conditions would damage PVC by thermal \whlch would bey degradation not to mention the warehousing problems^caused by such measures. A temperature reduction during degassing on the other hand would mean a further (Installations 7 prolongation of the process. Specially equipped degassing ^ tdurlngy would have to be constructed* Adopting appropriate measures ^ compounding seems a more reasonable approach today. ucc 12- 031574 VC-Content (ppm) log. scale Dense Particle Porous Particle Days Abatement of Residual VC In PVC During Storage In Bags The two curves show the development for two types of PVC with approximate Ivlscoslties J equal ^ whereby the curve with the flat slope represents (while; a relatively dense particle * the other curve represents a porous particle. uce -13- 031 <.n Path of Diffusion The length of the path of diffusion during degassing depends on - the particle size, the larger the particle the longer the path of diffusion. - the particle density, e.g. porosity and porosity characteristic. The more pronounced the porosity or specific surface area, the shorter Is the diffusion path. La variety of end products j Production of and the application o processing techniques would be Impossible If PVC were exclusively produced to obtain Vpurposes.) optimum particle properties for degassing ^ The market requires PVC properties ranging from the finest to the coarsest and from the most porous to the gel particle. The viscosity of PVC a function of polymerl- zatlon temperature also influences Its porosity. The higher the .polymerization temperature,the lower the viscosity and the denser the particle. Temperature Relationship Degassing of PVC Is accelerated with Increasing temperature. Limiting, however. Is the thermal stability of PVC. The addition of stabilizers at this stage Is hardly suitable since the scope of application for the product would be significantly reduced. Hence commercial PVC contalnsfcertain amount of residual VC. have to be taken it follows that preventive measures Las welly In the area of processing^h order to prevent a health hazard by VC volatility. -14 Abnahmc des VC-Gehalts in Abhlnglgkeit von dor Lagerzeit (Beispiel 2) Reduction of VC-Content as a result of warehousing time PVC 1600 ppm VC I wenige yTage \/ | Sack lagerung 570 ppm VC Marehousing for several days In bags Days ITag 3Tage 5Tage 8Tage \Z "\ 210 ppm VC 110 ppm VC SO ppm VC in Softener Schale 10 ppm VC In open cup Modellversuch mit einem PVCMuster von extrcm hohem VC-Gehalt. Boi hoher Temperatur und Vakuum sinkt der VC-Gehalt in wenlgen Minuten auf Brucbteile des ursprungiichen Werles txlt (Beispiel 3) Small scale test on PVC with extremely high VCContent Under high temperatures and vacuum,VC-Content drops In a few minutes to a fraction of the original level PVC 6000 ppm VC I 1120*C. ^200Torr \/ I 55 min. 40 ppm VC im Compound 200 nm Hg. In coirpound \/ 35 ppm VC in der Flaschenwandung In blown bottle wall ucc 031579 HEALTH PROTECTION IN PROCESSING AREAS We therefore present here some Ideas on how to avoid accumulation of VC In the work area atmosphere. Storing No special precautions are necessary for storing In silos, with the exception of access during maintenance and cleaning operations. Ample ventilation on the other hand should be provided In storage areas for bagged material In order to vexcessive; prevent accumulation of \ VC concentrations. Mixing Most processing methods which do not require pellets or ready made compounds vmlxers.) are preceded by mixing operations. Intensive ^ as used today and partic ularly the application of higher temperatures,stimulate and accelerate the liberation of residual VC from PVC thereby eliminating the major portion of the monomer. On one hand this presents an advantage as PVC processed In such a manner contains but traces of VC. On the other hand, however. It necessi tates safety measures for mixing areas and equipment. yclrcumstanceJ Up to several hundred ppm VC have been detected at mixer openings. Under any ^ this Is significantly higher than the pending standard levels. It Is therefore Imperative that these mixers are not vented toward the general plant area. The processing sequence of silo*mixer, cooler, processing equipment should for the same reason operate as a closed system with ventilation toward the outside. VC concentration In the mixing area can be held under 10 ppm by these measures. ucc t -17- 031579 Residual VC contents In relation to processing temperatures on a sample with particularly high VC content. PVC in the. Intensive mixer. ucc 18- 031530 In general terms hot mixing entails advantages,since significantly larger Idurlng J proportions of VC are driven off than ^ cold mixing as shown In the following examples. This ensures that none or only very small amounts of VC are released In further processing steps. Extruding IconflrmedJ A variety of tests ' ^ that the evaporation of VC from PVC Is significantly' UlsoV Impaired after thermoplastic conversion Into finished products. ThlsTapplIes yprocessingy to the hot melt as It emerges from >J/ equip- ment. Indicative Is the measurement of a 10 ppm VC level obtained directly ^Specialj at the exit of a large scale granulator.^ precautlons have to be taken at the hopper when processing powder b1ends,as heating accelerates the VC degasification. The recommendation goes to provide for sufficient ventilation at this point or even better to operate an enclosed system. Injection Molding Monitoring the VC concentration In the vicinity of Injection molding machines both In the Federal Republic as well as In Great Britain showed also a level under 10 ppm. Recoamendatlons made for extrusion processing apply here as well. Calendering In the calendering process attention should be concentrated on the Initial yequlpmentj processing steps. Mixing as well as preplastlf1catlon^have to be equipped with sufficient ventilation. Work areas around -19- ucc 031581 Abnahme des vOGehau* in Abhingigkeit von don Vorarboitungs* Decrease In VC-Content In relation to processing conditions bedingungen (Belsplel 5) pvc 600 ppm VC cold premixing and g? anulated ykail vorgemischt A120*C.5mia,200Torr? undgranuliert \Compoundierung V 220 ppm VC im Granuiat In Granulate 10 ppm'VC im compound Compounding in Compound 0 95 ppm VC In dor Flaschenwandung 10 ppm VC in dor Flaschenwandung In blown bottle wall ucc 031582 processing equipment are relatively free of VC exposure as Vyentllatlony calenders are already equipped with adequate T units for the elimination of plasticizer and additive fumes. Paste Processing Only minute traces of VC are liberated during processing of paste formulations from emulsion PVC at room temperature. This Is primarily attributable to the fact that emulsion PVC has the lowest residual VC content of all three lventilation) types of PVC. Typically,Installed ^ apparatuses which serve to eliminate plasticizer fumes during the curing step are satisfactory to eliminate traces of VC as well. Mandatory Incineration equip ment, which Is required for the elimination of organic vapors at these large scale processing Installations*provides an additional safety measure. VC CONTENT IN THE FINISHED PRODUCT Up until two years ago It was generally accepted that monomeric Vinyl Chloride gas would have evaporated completely by the time It reached the thermoplastic processing step and that consequently finished parts were free of monomer. This perception provided the basis for regulations as established by health authorities In many countries. Similarly In the U.S.A. PVC was classified In a group of materials generally considered as nontoxic with the designation of "prior sanctioned material." uec -21- 031583 Beim Kaltmischcn blcibt der VCGehalt unvcrandert. AnschlloOondcs Kalandricron 1st hinsichtlich dor VC-Content remains unchanged by cold mixing. Subsequent calendering Is not very effective In the reduction of VC. VC-Roduzierung nicht sohr otfoktiv 1 (Beispiel 6) PVC 300 ppm VC \/ 300 ppm VC kalt gemischt Cold Mixing kalandriert \/ J 160 ppm VC in 250 n Folio Calendered in 0.25 nn Film ucc 031584 tv. In the spring of 1974 reports from the U.S.A. Indicated that a 20 ppm VC content had been found In whiskey which was contained In PVC bottles. Subse quently the Food and Drug Administration prohibited the packaging of alcoholic Ito date; beverages In PVC bottles. In spite of concentrated effortsfro further infor mation could be obtained with regards to the PVC or the tused in this Instance In the U.S.A.7 analytical methods i'The following Investigations were conducted In Germany In order to clarify the circumstances: Development of more accurate and Improvement of known analytical methods. Investigation of VC migration Into food products from consumer products such as packaging materials. Investigation of the Impact of processing characteristics on the VC concentration In consumer product Representative food products and storing conditions such as stipulated In the recommendations for consumer products by the Federal Health Administration were used for the Investigation of the migration of VC from PVC packaging materials. The following representative food products were used: water, 302 concentration of acetic acid, IDS concentration of alcohol and edible oil. They were stored In PVC bottles for 10 days at 40C, which at room temperature corresponds to a time period of several months. 40% and 50% alcohol concentrations were Included In order to verify the surprising results as reported In the U.S.A. lhad] The applied analytical methods^ a minimum detection level of 0.2 ppm with the solutions In water and 1 ppm with edible oil. ucc 031535 -23- Test results were generally below or In the vicinity of the minimum detection level even with relatively high VC concentrations In the bottle wall and hence Usj fell significantly below the 20 ppm VCVdetected In the U.S.A. The Commission for Plastic Materials of the Federal Health Administration ^produced) comnents on the "examination of consumer products$ from PVC according to the latest state of scientific knowledge": "The Comnlsslon for Plastic Materials of the Federal Health Administration reports In Its 57th Sesslon.that to date there are no Indications of a health hazard by consumption of food products which had been packaged In PVC. Experimental 90 day animal tests had been concluded In September 1974 by the Dutch Central Institute for Food Research during which substantially higher Ithan those) amounts of VC had been administered ^ which could possibly be expected as a result of contact of PVC with food products. There were no Indications of a toxic effect. In view of this the oral Intake of traces of VC with food products has to be treated In a different way then the Intake of VC by In halation. Analytical tests on a broad range of food products which were packaged in commercial PVC resulted exclusively In levels below 1 ppm VC (e.g. less than (VC per kq.ofy 1 mg*food product). These tests are presently continued on a broader scope. Based on animal testing and analytical results the Commission for Plastic (as a precautionary measure Materials of the Federal Health Administration has no reservations 1t+tfie VC content In food products Is limited to 1 ppm until new evidence is presented as a result of the conmlssloned long range tests. ucc -24- 031586 The Federal Health Administration expects that all technological possibilities for a reduction of the VC content In the production of PVC materials as well as In Its conversion to consumer products will be adopted.1* The Food and Drug Administration In the U.S.A. to date has considered a limitation of the VC content to 10 ppm In finished products which are destined for contact with food products; according to the latest Information, however. It Is expected that the FDA Is working toward an arrangement with which the lable toy Industry is presently^comply. The FDA has not arrived at a decision yet whether to Impose a VC limitation In the finished product or In food products or respectively In representative test media and what the level of such limitations should be. METHODS FOR MEASUREMENT OF VC Vbey Refined methods have tovapplled and highly sensitive Instruments have to be used for the control of VC concentrations In the ppm range. This applies to monitoring of work place conditions In PVC producing and processing plants as well as to securing the consumer protection In PVC packaging of food products and to the determination of the residual monomer In PVC. N Draper Capillary Until now the detection level of the most simple and economical method for thasJ the determination of VC In altysufflced: the analysis by the "Drager Capillary Vinyl Chloride 100/a," In which air Is being sucked through the capillary with a hand pump. If after 40 strokes the color of the capillary Is unchanged, then the VC level In the air lies below 50 ppm. It can hardly ucc 031587 be expected, however, that this detection limit will suffice for plant tt monitoring purposes. The Drager Capillary will, however, retain Its signif icance In a quick spot analysis,particularly since It has a relatively high vwhich serves as Indicator J reliability. Reaction with Potassium Permanganateloccurs aside from Vinyl Chloride only with a limited number of other mostly unsaturated organic compounds such as ethylene or chloroprene. These should however resent) rarely^in conjunction with VC. only FID-Method A significantly more sensitive method, which dependent on Instrument design Ifor) can be applled^^spot or constant monitoring In exhaust ducts,capitalizes on the fact that during Incineration of organic substances In a hydrogen- mlxture, air- Ions are created which significantly Increase the electrical con- (Instrument^ ductlvlty. Inside such a FID (flame Ionization detector) the flame ywlthin I bums ^ an electrical field which Is created between the torch nozzle lfounter>> and aH' electrode by the application of approximately 200 volts. The resulting Ions move In this field, - the resulting amperage is approximately proportional to the amount of the Introduced organically bound carbon. The ^conceivably J detection level of the FID could V Be lower than 1 ppm. If Its selec tivity would permit this. It responds practically to all organic compounds, \only known/ such thabjcondltlons In existence at the test location would allow a judgement as to what substance caused the signal. At low concentrations this naturally Is always an uncertainty. Advantageous Is its fast response of approximately 1 second which allows rapid and successive monitoring of several locations. ucc 031588 -26- Ionoflux-Instrument lonoflux Instruments work also on a continuous basis, however with higher selectivity. Here the Increase In electrical conductivity of atlabsorptlon solution,which Is proportionate to the VC content,Is being measured. Initially the VC Is burned with a catalyst whereby hydrogen chloride and chlorine are derived from chemically bound chlorine. Subsequently both gases are absorbed In a hydroxylamine solution, whereby the chlorine Is converted to hydrogen chloride. The Increasing conductivity caused by the total amount of hydrogen chloride corresponds exactly to the Introduced amount of VC. These reactions require a certain amount of time, such that an Indication of the VC content does not show until 5 minutes after dosage. The detection limit of this method Is 1 ppm. Ultrared Instruments ^ Ultrared instruments represent an effort to Improve the selectivity on the 4 scale of trace concentrations. Two types can be distinguished: the Uras-type Vwhlch usesj which does not work dispersive bufclrthe test gas as reference gas and those Instruments which operate dispersive with prisms and filters. Gas-Chromatography The highest degree of selectlvltyVachleved by gas chromatography which, however, can only measure IThls method V i .. continuously/ ^ tbfaolnes the advantagejbf selectivity with high accuracy and sensitivity. Here the flame Ionization detector Is hooked up with a coupling unit which allows the classification of the test specimen by boiling point and affinity of Its components. These are Intro duced one by one by means of the carrier gas Into the detector which analyses 1) Translator's Note: Infrared (?) -27- ucc 031589 them quantitatively, from exhaust ducts. Samples can be taken from any areas or extracted Detection Limit and Selectivity of Various Methods for the Determination of Vinyl Chloride in Air Instrument Detection Limit (ppm Volume) Selectivity Interference Factors M Drager Capillary 50 Limited Unsaturated hydrocarbons FID 1 None All Hydrocarbons and Ammonium Ionoflux Type 1 Slightly Halogenated Limited hydrocarbons Ultrared (Uras-type) Ultrared (Dispersive) 5 Dusts, Limited Vapors, Carbon Dioxide 0.7 GasChromatography 0.2 Available Minimal W VC contents In food products and In PVC can be defined Inrslmilar fashion. Food products such as mineral water, wine vinegar or alcoholic beverages, as ^hypodermic,/ well as molten fats and oils are Introduced with a needle In the dosage section which Is heated to 100C, whereby volatile portions evaporate ucc 28- 031590 Immediately and are carried away by the carrier gas. For testing of PVC, a solid which can not be Injected, a solution of the isuch as in tetrahydrofuran j polymer^is required asa first step. Obtainable detection limits for VC are 0.2 ppm In air (volume ratio),^ 0.2 ppm (weight ratio) In water and fat based food products and 1 to 5 ppm (weight ratio) for PVC. Sampling Correct sampling Is very Important. Sample size must be large enough to show a representative cross section of the total. The usual methods Iblendlng.y to obtain such an average sample Include ^ dividing, homog enizing and the like. In the case of PVC in powder form It has to be recognized lvolatilize; that particles which lie near the surface `"faster than those which are located in the center of the bulk. VC-REDUCTION land flashing; Residual monomer which after polymerlzatlon^remalned In the PVC (to a large extent IntoJ typically volatilizes i tfie atmosphere during drying, classifying and air conveying operations* The Intensive efforts by the industry to operate at low emission and 1) PPM (volume ratio) and (weight ratios) differ In the determination of Vinyl Chloride traces in air numerically by a factor of 2.6. PPM (volume vvoTumey J ratio) represents tne^rUllo of Vinyl Chloride gas to total gas PPM (weight ratio) on the other hand Is the weight portion of Vinyl Chloride of the total weight. The density of Vinyl Chloride gas Is approximately twice that of air. -29- uce 031591  ^volatilization) loss levels concentrate on achieving a radical^ method applied to a system which Is hermetically closed to the ambient atmosphere, and which is expected to further lower the VC content In commercial PVC. The administrative regulations for the Environmental Protection Law - the so called"Techn1cal Direction Air"- Imposes a strong restriction on VC contamination vyc/ allowed to the environment with a maximum of 150 mgfper m Ivolume j exhaust^with a flow rate of 3 kg per hour. In view of the measures to be taken at all processing operations, knowing the concentration ^commercialJ of VC in the various types of sf PVC should receive considerable attention. These VC contents are presently still to be used as guidelines for the protection of the worker In ` processing areas. It is self-evident, however, that this can only be a temporary stop gap measure. By consensus among PVC producers,the solution to the VC problem can only be achieved through a ithe i icommercial PVCJ drastic lowering of4VC content in J or compound. Present Reference Values An opinion on the (content as experienced todayJ residual VC Sr has to remain very vague, however, unless It refers to specific types of PVC. Nevertheless some guideline values shall be given as follows: With emulsion PVC a significant factor Is whether it Is a fine or coarse grain type. Finely sprayed emulsion PVC contains a maximum of 10 ppm VC, a typically level Is 2 to 7 ppm. Coarsely sprayed emulsion PVC generally contains 150 to 200, maximum approximately 250 ppm. Special grades such as used for ucc -30- 031592 la maximum level of} paste formulations containfapproxlmately 70 ppm,typically however,around 20 ppm VC. f The range of applications for suspension PVC Is much larger than that for the other two types of PVC. Correspondingly many different grades of suspension PVC are being produced to satisfy market demands. General comnents on Vsingle J the VC content are difficult, as there Is no correlation to any ^ property. Icategorlcally I An attempt toireduce tne VC content leads to a change In the overall properties of PVC. Therefore only close cooperation between processor and producer makes the attainment of a minimum VC content possible with a simultaneous maintenance of ylt follows, that,; property differences. ^ presently only a range of VC content between yfor j ^postulated.} 10 to 1,000 ppm ^ suspension type PVC can be V These values could be can higher for specialty types. The supplier provide pertinent Information. Typically residual VC contents for bulk PVC fall In the range of Vspeaking,J 100 to 1,000 ppm. Bulk PVC degasses particularly quickly. Therefore, generally ^ VC contents are significantly lower at the processor level. (alone } These broad Indications^show content Is simply Impossible. that a general statement on the monomer Imakesy The required differentiation % a direct dialogue for the determination of exact levels between producer and processor Indispensable. In additlory the above Indicated residual VC contents have resulted from testing of freshly produced PVC. Further degassing occurs during the various shipping steps and storage In bags or silos. It Is therefore Impossible to make binding ucc -31- 031593 statements on the residual amount of VC In existence at the time of delivery to the processor. Only maximum values could possibly be Indicated. Likewise at PVC producer can not guarantee a specific minimum storage time with corresponding VC reduction. The reason for this Is,that all PVC producers maintain a lower number of production lines than the number of grades they offer. Several grades are therefore successively produced on one line. It follows that production has to be In large lots and shipments have to be equalized over constantly and significantly changing Inventory levels. As Un conjunction withy a consequence the shipment of a mixture of freshly produced ^ already several weeks aged PVC Is unavoidable. Future Considerations Vare undertaking/ All PVC producers ^ intensive efforts to develop new processes which in spite of technological difficulties will allow a further,significant reduction of residual VC contents. Pilot plant know-how Is already available. icomnerclal j seal1ng up to^PVC production quantities. V,being J Much work Is presently^done In Design, ordering, delivery and Installation of new equipment require time however. Finally, as experience shows, time Is also required for a legislative examination and approval of new processes. Overall, there Is no doubt, that In time we will be successful In upgrading production processes to the extent that health hazards can be eliminated In the future. -32- ucc 031594 1 THIS IS PVC Manufacturing Polyvinyl Chloride Is produced from Vinyl Chloride by polymerization. Commercial polymerization processes are classified as follows: Emulsion Polymerization Suspension Polymerization Mass or Bulk Polymerization. Emulsion polymerization is the oldest process; here the combination water/ Vinyl Chloride Is transformed into a stable emulsion by the addition of emul sifiers or soaps (approximately 2%) and under agitation. Polymerization occurs inside so-called"soap micelles"with the aid of water soluble catalysts such as Hydrogen Peroxide or Potassium Persulfate. Surfactants such as used today In detergents, are added as emulsifiers. The resulting latex Is converted to finished product by precipitation and spray or rotary drying. The suspension polymerization process entails the dispersion of monomer droplets Vthrough ) In water through Intensive mixing ana ^ the addition of suspension stabi lizers. Polyvinyl Alcohol and derivatives of Vact as suspension stabilizers/ celluloselwhicn have the task to further droplet formation and to prevent sticking of the Individual polymerization particles. The reaction Is initiated by Vinyl Chloride soluble catalysts. The resulting PVC is separated from the la centrifugue/ water phase by ^ or decanting and dried. -33- ucc fr>] SQS yl Mass or bulk polymerization of Vinyl Chloride with activators Is accomplished without solvents or dispersants. The main portion of the polymerization proceeds In a powdery state, whereby agitation and heat transfer present special technical problems. From the point of view of processing technology, the mass process shows several advantages over the previously explained processes. Drying of the product Is not necessary. Mass PVC Is also com pletely free of additions such as emulsifiers and protective colloids. Catalyst residues are the only contaminants. The PVC particle is very porous which favorably affects Its processability. Properties \ the j Hardly any other plastic material shows4^ wide range of application possi bilities of PVC. This Is not only made possible by the various con version processes but also by the availability of a wide variety of raw Vconstituents; material ^ and processing aids. Polyvinyl Chloride's properties are based partially on its chemical composi tion, Its structural characteristics and the various polymerization techniques, and partially on the effects of certain additives, which influence the process- ability and application of the pure raw material. This material is characterized \suchl Uhe j by parametersvasiK-Va1ue, particle shape and particle size distri bution. Particle shape, size and construction Influence Vhave an/ Important product characteristics. TheyHnfluence on bulk density, flowabillty, and plasticizer absorption and frequently have a bearing on which compounding i irr -34- 031596 and conversion processes are to be chosen. A particle with good flow characteristics yfor pneumatic conveying and hopper/ lto processingJ shows advantages 'V feeding^ equipment. A high bulk density has a favorable effect on the throughput In extrusion, operations. Injection modllng > / or mixing The production of dry blends requires a porous particle construction (with high plasticizer absorption) In conjunction with good flowablllty of the PVC powder. The viscosity characteristics of PVC paste formulations are among characteristics which (.Different) can be Influenced by the polymerization technique.^ Paste PVC's of the same K-Value, homogenized with the same amount of the same plasticizer could under the same temperature conditions and residence time lead to completely different viscosity and flow properties. Nonplastlclzed compounds show good electrical properties. PYC can be formu late^T^ransparent or opaque compounds. Nonplastlclzed PVC Is resistant to dilute or concentrated acids and bases, mineral and plant oils, alcohols and aliphatic hydrocarbons. * Rigid PVC formulations show good weathering properties. If suitable stabilizers and pigments are chosen. Flexible PVC Is generally less weather resistant than rigid PVC. ucc -35- 031597