Document zdm24QxvmO53VOqd0VDdqok06

R&S 113281 BIO-MEDICAL.RESEARCH DOCUMENT DESCRIPTION PORK Duplicat .in all cards:-- year as-1961- File number [Right justify [Numeric only] Author (s), as Last Name. FS (No Punctuation) and coden for journal as JAMA preceeded by one blank space 1 20 21 ________________ 40 4160 '* 77 78 HT | Sub-Index Code 61 62 Title of Report: end with space-hyphen-hyphen-space. Follow with Index Terms separated from each other with comma--space* Avoid other punctuation; do not abbreviate* g* r Mm U'/l /tv * *1 Mr.; ?7^ sjt. 'c/--r/Zc/*> f; M /=)v- r;/ /- a' ---AV/r it'Cirrcy-^ .i-rnyszt-. 21 22 23 24 Source (Journal, Vol. Number images, Date ) *1 62 Brief Summary 12 10 SUMMARY: 61 62 61 62 63 64 c An tndustrial hygiene evaluation is pres nted concerning experimental data includldfirthe preceding paper on thermal degradation products from hot-wire and "cool"-rod cutting of PVC film but, in this paper, limited to film used in meat-wrapping operations. Room air cone ntrations of less than 0.2 ppm HC1 and less than 0.05 ppm benzene can be maintained by a number of fact rs, including minimal dilution ventilation. Estimates of room air concentrations of degradation products are presented using average values of amounts produced per cut. The^^ relation of these concentrations to TLV's is given, together with methodsof suggesting TLV's for substances n listed by ACGIH or OSHA. Room air concentrations for the 12 degradation products for which TLV's are assigned, based on average values per cut, were no greater than 0.3% of accepted limits. Room air concentrations of DOA are not determinable from available data but present information does not indicat that exposure to DOA causes airway hyperreactivity. The cool rod, rather than the hotwire, is recommended as good industrial hygiene practice, producing no apparent PVC degradation products, even though similar amounts f DOA ar volatilized. Industrial hygiene evaluation of thermal degradation products from PVC film in meat-wrapping operations WARREN A. COOK* Professor Emeritus. The University of Michigan. Ann Arbor, Ml 48109 intr duction A number of studies have been made ofpotential hazards to micro furnace were identified by NIOSH,11' but in order to employee health in meat wrapping departments of determine just what substances the meat wrapping supermarkets. Most comprehensive are those conducted by operators were exposed to, there was a need for the National Institute for Occupational Safety and Health identification of all degradation products of significance (XIOSH) and its organizational predecessor, the Bureau of Occupational Safety and Health, U.S. Department of HEW, over the six years through 1977. An initial report'1* concluded that "there appear to be no apparent health hazards presented by PVC film fumes generated in meat wrapping to normal healthy persons employed as meat from hot-wire film cutting and a determination of tja amount of each substance produced, ^ This basic information has been provided through a research project that is thesubject ofa paper1** in this issue of AIHAJ. wrappers.J f , The NIOSH report'2* at the end ofthis period includes all -known information on hot-wire cutting of PVC packaging film up to that time and a summary ofNIOSH health hazard evaluation studies of meat wrappers and cutters. The conclusion after conducting these extensive studies was that "ir cannot be determinedfrom these studies whether actual allergic sensitization and resultant bronchial asthma occurs from exposure to these contaminants " It was noted that "hot wire cutting of PVC meat wrappingfilms and thermal activation ofprice labels can release irritant substances into the meat wrapping work environmentbut that"breathing zone concentrations of the irritant substances emitted are low when compared to established occupational health exposure standards." Much of the information in the NIOSH report'21 has been published in two papers, one on environmental exposure and toxicology'*' and the companion paper on clinical studies.'4' In this latter, more recent paper, the conclusion quoted in the preceding paragraph was again stated. A small number of degradation products on heating PVC film samples to the hot-wire temperature of200-300 C in a APresent address; 713 Emory Drive, Chapel Hill, NC 27514. ___ ______J epplicationof research"dataonthermal degradation products An application ofdata developed in this research project1** is the evaluation of exposures to these substances of persons engaged in PVC film meat wrapping operations. The research project included five types of films, nly one of which. Type RMF-61HY, is used for meat-wrapping operations. This discussion is limited to industrial hygiene aspects of the experimental results -utilizing Type RMF61HY film, since the other four types included in the research project are used forsuch otherpurposes as produce wrapping and carcass wrapping, operations n t under consideration here. Furthermore, data are included only on Batch No. 1588 of this type film, since only this batch of RMF-61HY film, as discussed in the research paper, was of sufficiently recent origin to be handled in a representative manner and consequently to produce representative results. The plasticizer used in this film is di-(2-ethylhexyl) adipate, commonly called dioctyladipate (DOA). The experimental data in the following discussion anQP from the cited research project, except where specifically noted. CopyngN IfO. Anwrinn mdimm Hrgiwn *wwl sot Am. M. Hyt Axsc J. (11) Ml. 1980 R&S 113282 breathing z n air samples hydrogen chloride Three air samples were collected during hot-wire cutting of PVC film RMF-6IHY in a closed room 4Z3mJ (1500 ft.J) in volume with dimensions as given in the research paper that also ootes the sampling point at the breathing zone of the operator. Even though an extremely sensitive analytical method was used, the amount of HQ in the air was not sufficient to permit a quantitative result. The largest sample collected, 75 liters, established that an average of less than 0.1 pan per million (ppm) of HQ was present over the 75minute sampling time. With 240 cuts ofthe PVC film being made during this period, the HQ concentration would have increased from zero at the start to something less than 0.2 ppm at the termination of the sampling period for the average to have been less than 0.1 ppm. Actually, the increase in the concentration time would not be a straightline but would be a hyperbolic curve asymptotic to a maximum at equilibrium between introduction of HQ into the air and the several factors causing its removal from the air. These factors include solubility of the HC1 in moisture (a greater factor in meat-wrapping rooms than in the test room), adsorption onand reaction with the surfaces contacted, and a small but definite amount ofdilution from convection currents through loosely fitting doors and intermittent opening of doors. The investigators note that the value ofless than 0.1 ppm is less than 1/50 of the threshold limit value (TLV) for HQ; but conservatively, recognizing a build-up with passage of time, suggest that the continuing exposure might be on the order of less than 1 /10 of the TLV. A series of laboratory tests conducted by other investigators'*' using artificially severe operating conditions causing excessively smoky cuts gave results of 1.9 ppm HQ at a sampling location 7 in. above the hot wire and 0.2 ppm .. >HQ,atbreathingtlewll7-18in.abovethesealingpad. - ' calculation is of Interest .of the amount of diluting air j - nhatswould 'be requiredfto keep the .concentration of HQ below 1/10 of its TLV using the formula in the Industrial Ventilation Manual of the American Conference of Governmental Industrial Hygienists (ACGIH).'7' The amount of HQ released into the air per minute was calculated from the amount per cut (4 micrograms -- the average of six cuts with Batch 1588 of film RMF-61HY) times the operating rate of 192 cuts per hour (240actual cuts over a 75-minute period). A K value is incorporated in the formula to serve as a multi-purpose safety factor to maintain air concentrations well below the TLV. The K value may vary from 3 to 10 with the latter resulting in the highest amount of dilution air required. Using this maximum K value of 10, the amount ofdilution airrequired foreach hot wire cutting unit would be only 0.17 m3 (6 ft.3) per hour. More than this amount of air change occurs normally even without benefit of mechanical ventilation. For comparisons of the findings under these test conditions with results fair analyses taken at the breathing zone of the operator during hot-wire cutting of PVC film in four different stores under normal operating conditions, taencjn In&tftriM Hy|im AaodtSen JOURNAL (41) 7/80 a James"' reports that theaverage ofeight determinationswas 0.57 ppm HO, close to 1/10 of the TLV, with a maximum of 1.49 ppm HC1. benzene Following the 240 hot-wire cuts in the test room prior to ventilating the room, an air sample was collected for 20 minutes for determination of low-boiling hydrocarbons such as benzene and 2-ethyl-l-hexene. No low-boiling hydrocarbons were found, using the GC/MS unit capable of detecting benzene in the order of3 micrograms. With the 20liter air sample, as little as 0.05 ppm would have been detected. Accordingly, the accumulated concentration of benzene produced was necessarily less than 1/20 of the proposed OSHA TLV limit of I ppm and less than 1/200 of the existing OSHA TLV of 10 ppm. estimates of room-air concentrations of degradation products from PVC film type RMF-61 -HY (batch 1588) data used in estimates In calculating the estimates of room-air concentrations of degradation products, the average amount from 250 cuts, essentially the same as the maximum number ofcuts used in the breathing zone samples, was relatedto a room of42.3 m3 (1500 ft1), the volume ofthe test room. With this number of cuts, it was considered that equilibrium conditions would be reached. For the degradation products, HQ, plasticizer (DOA), benzene, toluene, carbon monoxide, the average of all test runs on Batch 1588 as reported in the research paper11' are used in the calculations. Since only Batch 1959 was used for the acrolein tests, these results were used. For benzyl chloride, negative results from 15 cuts indicated less than 1 fig, the mass spectrometer detection limit. F r the remainder of the degradation products as listed in Table I, determinations 'were conducted^ b^^gas chr matograph/mass spectrometer. As 'disomed;in the research paper,"' `smoky cuts were' required 'to produce enough degradation product for quantitative results with this latter group of degradation products. As benzene amounts could be determined from normal cuts as well as from sm kycuts, the ratio of these values for benzene was applied to the smoky cut results of these other products to obtain a value for normal cuts. The average values for these additional degradation products have been taken as 9/10 ofthoselisted from Batch 1588 in Table VII of the research paper11' for dean cuts and 1/10 of those listed for smoky cuts since, according to the investigators, approximately one of ten cuts tended to be smoky. threshold limit values Threshold limit values are listed in Table I for each of the substances for which these have been established by ACGIH or OSHA except that for benzene for which the value currently proposed by OSHA is listed. No threshold limit value has been suggested by these - sos . R&S 113283 4b TABLE I Estimation of Average Room-Air Concentrations of Degradation Products 3J Resulting from Hot-Wire Cutting of PVC Film Type RMF-61HY (Batch 1S88) 99 (/) Degradation Average Amount Average Concentration in Percent Product TLV (ppm) Produced per Cut 1S00 ft1 Room from 250 Cuts of TLV Hydrogen chloride 5 4 M0 0.016 ppm 0.3 W ro 00 Plasticizer (DOA) A 36 m0 0.014 ppm A 4* Benzene 1* 92 ng 0.0002 ppm 0.02 Toluene 100 S3 ng 0.00008 ppm 0.00008 Acrolein 0.1 120 ng 0.0003 ppm 0.3 Carbon monoxide so 1.75 uS 0.01 ppm 0.02 Benzyl chloride 2-Ethyl-1 -hexene Ethyl benzene Styrene n-Propylbenzene Propenylbenzene0 indenec Naphthalene0 Unidentified Unidentified 1 A 100 100 100A 100A 10 10 A A 0.07 pg 210 ng '21 ng 37 ng 37 ng 13 ng 13 ng 6 ng 52 ng 6 ng 0.0002 ppm 04)003 ppm 0.00003 ppm 04)0005 ppm 0.00005 ppm 0.00002 ppm . 0.00002 ppm 0.00001 ppm 0.0003 m/m' 0.00004 m/m' 04)2 A 0.00003 04)0005 0.00005 0.00002 04)002 0.0001 A A ARefer to text `Proposed OSHA value Unconfirmed identification agencies for DOA. An experiment of an 8-hour exposure of rats to saturated vapor resulted in no deaths.**1 NIOSH(2> cites a Monsanto Company report that "10 rats were exposedfor 4 hours to 900 mgfm1 (59ppm) generatedat 89 C and observedfor 14 days. None ofthe rats died and no untoward behavioral reactions were observed." Later experiments"01 with 6-hour exposure to 200 mg/m* gave similar results. r Slight ^irritation owurjed.from_ 24-hour contact .of rabbit^skin (1.9/8.0) andfromUquidDbA inthe eye (1.4/110.0) .with normal ap'peaianoe 48 hours.later.Tbe LDjo on intravenous injection ofthe rat has been reported"11 as 900 mg. kg and of the rabbit as 540 mg/kg, indicating DOA as "slightly toxic.Ktu,ul These inhalation studies included only survival or death on acute exposure and observation over 14 days. Toxicological data on substances of similar constitution are sometimes helpful in suggesting a probable TLV but we know of no substances similar to DOA with such information. Although neither ACGIH nor OSHA have TLV's for npropylbenzene or propenylbenzene, the close structural analogy of the former substance with ethylbenzene and of the latter substance with styrene indicates a TLV of 100 ppm as applicable to each of these substances. No TLV has been published for 2-ethyl-1-hexene; but from analogy with similar unsaturated hydrocarbons,"4* its principal action may be expected to be asphyxiant and anesthetic. Suggestions for threshold limit values for the substances that caused film RMF-61HY to produce the two unidentified peaks noted inthe research paper and included in Table I present a problem. An approach to whetherJ^e is a reasonable probability that concentrations f mKc unidentified substances as low as 0.0003 mg/m1 r 0.00004 mg/m1 could cause a physiological effect such as airway hyperreactivity may best be through a comparison with concentrations of known sensitizers at their threshold limit values. Of nearly 600 chemical substances for which TLV's hiavebcen published byACGIH,*131 thesubstances that must l be kept at the lowest concentrations to avoid causation of airway hyperreactivity are the isocyanates, ofwhichtoluene diisocyanate (TDI) has been most extensively studied. A recent criteria document published bytheNational Institute for Occupational Safety and Health"41 stipulates a limiting concentration of0.005 ppm for diisocyanates. F rTDI, this value is equivalent to 0.035 mg/m1. This standard is "designed toprotect thehealth andprovidefor the safety of employees for up to a 10-hour workshift. 40-hour workweek, over a working lifetime."The concentrati ns of 0.0003 mg/m1 and 0.00004 mg/m1 are thus 0.9% and 0.11%, respectively, of what is considered an acceptable concentration for the most severe sensitizer on which * quantitative exposure/response data are available. Comparison values for these unidentified substances must be in terms of milligrams per cubic meter as lack of knowledge of their molecular weights prevents calculation of the corresponding parts per million values. The TLV of HQ is well established at 5 ppm, bul^^e particulate DOA is present as an aerosol on which soraof the HQ may become attached, the questi n arises as to 510 Ab. tad. Hyt.Aimc.1 (41) July. 1980 . v .* *. . whether concentrations of somewhat less than 5 ppm may, through this mechanism, reach the lower respiratory areas and cause irritation in these areas. Such gas/particle interaction has been discussed in relation to fire situations,,IT*u, but in the experiment with HCl/soot aerosol reactions/17' the concentrations of HC1 were over 100 ppm, and in that with HCl/water aerosol reactions/1*1 concentrations of 60, 600, and 6000 ppm gas-phase HO were used. All of these concentrations are far beyond the range of HCl produced in hot-wire cutting of PVC film and so not applicable to the operations under consideration. The most extensive researches on potentiation of the effect of an irritating gas by aerosols are those conducted over more than a decade by an investigator using sulfur dioxid as the irritatinggas. In one ofthese research projects where the irritant gas was inhaled with each of a variety of aerosols/1** it is stated that "It is plain from the data presented in thispaperthat allaerosolsdo notpotentiate the response to sulfur dioxide." and in a subsequent paper/30* that "neither iron oxide nor open hearthfumaee dust affect the response to sulfur dioxide." On the basis ofthese results, it cannot be assumed that any given aerosol will potentiate the action ofan irritant gas without demonstration through specific research. Such research has not been conducted c ncerning the potentiation of sub-TLV levels of HCl by DOA aerosoL All of the substances listed in Table I are readily volatile liquids or gases with the exception of DOA and naphthalene. It was found by the research investigators that most of the DOA volatilized by the hot wire condensed on the surrounding hood surfaces, the portion remaining as a vap r to he collected by an impinger being too small for quantitative measurement in an initial experiment. It is believed that, in use of hot-wire film cutters in meat wrapping operations, a portion of the DOA will condense . onto adjoining surfaces but thatsome portion ofthe amount volatilized will'ieachthe breathing zone ofthe operator. As no publications of results of air analyses for DOA at. the" i'i operator's :;breathing zone7 under normal' operating conditions are available, just what this portion or the total am unt volatilized will be remains conjectural. From the calculation of the average amount recovered from washings of the hood surfaces on making cuts offilm Batch 1588, this concentration would be some value less than 0.014 ppm. As listed in the final column ofTable I, the concentrations of the degradation products for which TLV values are assigned on hot-wire cutting of RMF-6IHY film. Batch 1588, on 250 cuts in a 1500 cubic foot room are no greater than 0.3% of their respective TLVs. cool rod PVC film cutting On finding no HCl evolved when the so-called cool rod cutting device was used or in the airflushed from the top ofa flask in which a sample offilm Batch 1588 was maintained at the cool rod temperature of 135 C (275 F), it appears probable that PVC does not degrade at the cool rod temperature. The finding of a total of 6.3 micrograms of HCl in rinses of surfaces of the flask and tubing leading to the sampling bubbler indicates either that the amount f HCl that may halve been produced by degradation was a thousandth r less of that produced by hot-wire cutting or that this minute amount may represent contamination. Negative results for benzene and toluene also indicated that PVC does not thermally degrade at the cool rod temperature. The amount of DOA volatilized by the cool rod device within the hood was in the same rangeas when using the hot wire, this result being ascribed to the fact that the rod was not being turned off during sampling. Keeping the cool rod turned on during sampling would increase the temperature within the hood, thus causing more of the plasticizer to remain volatile. conclusion An analysis of the results of the research1" on thermal degradation products ofPVCfilm usingthe hot-wirecutting device in meat-wrapping operations showed that the average concentration of hydrogen chloride as produced in a closed room by hot-wire film cutting was less than 2 percent of the OSHA TLV and that of benzene less than 5 percent of the proposed OSHA TLV and less than 0.5 percent ofthe current OSHA TLV. Justhow much less these values actually were is indicated by the results of the experimental gas chromatograph/mass spectr graph results as presented in Table L These GC/ MS results indicated that the concentrati nof degradation products for which TLVs are assigned would be no greater than 0.3% of acceptable limits and in most instances much lower. Thus it would appear , that any workroom exposures to such products w uld be insignificant from an industrial hygiene standp int.F rthe DOA, the concentration is less than 0.014 ppm; how much less is not determinable due to the presence of the dose surrounding hood structure underexperimental conditions, te'factor that, is not existent under actual operating conditions. Information presently available does not indicate that exposure to DOA causes airway hyperreactivity. ' Investigation of the cool rod PVC film cutting devicr indicated that PVC does not degrade at the temperature o the cool rod but that the amount ofDOA volatilized withii the hood was comparable to that using the hot-wire device The continued elevated temperature within the dosed hoot would not be a factorin the actual meat-wrapping peratio: and lesser volatilization of the DOA would accordingly b expected even though in meat wrapping the cool rod is kcj on. In accordance with the industrial hygiene viewp int thr all exposures should be kept as low as is practicably feasibh the cool rod device is to be recommended. references 1. Vandervort. R.: Polyvinyl Chloride Meat Wrapping Ft. Study. Bureau of Occupational Safety and Health, Cineinm OH (1971). 2. Vandervort, R. and S.M. Brooke: Health HazardEvalueti szeu ssy American Industrial Hygiene Association JOURNAL (41) 7/80 R&S 113286 1 ,,Determination. Report No. 74*24, 92, 95*246, National ,, Institute for Occupational Safety and Health, Cincinnati, OH (1975). 3. Vandervort. R. and S.M. Brooks: Polyvinyl Chloride Film Thermal Decomposition Products as an Occupational Illness. 1. Environmental Exposures and Toxicology. J. Occup Med, 79:188-191 (1977). 4. Brooks, S.M. and R. Vandervort: Polyvinyl Chloride Film Thermal Decomposition Products as an Occupational Illness. 2. Clinical Studies. J, Occup Med. 79:192*196 (1977). 5. Boettner, E.A. and G. Ball: Thermal Degradation Products from PVC Film in Food-wrapping Operations. Am. Ind. Hyg. Assoc. J. 47:513*622 (1980). 6. Van Houten. R.W., A.L Cudworth and C.H. Irvine: Evaluation and Reduction of Air Contaminants Produced by Thermal Cutting and Sealing of PVC Packaging Film.Ant tnd. Hyg. Assoc. J. 35:218*222 (1974). 7. ACGIH: Industrie/ Ventilation--A ManualofRecommended Practices. 15th Ed., pp. 2-1, 2. American Conference of Governmental Industrial Hygienists, Cincinnati, OH (1978). 8. James, O.G.: Cool Rod Film Cutting Device Ends Packaging Room Fumes. Package Eng. (March. 1975). 9. Smyth, H.F.. Jr., C.P. Carpenter and C.S. Weil: Range Finding Toxicity Data: List IV. A.MA. Arch. tnd. Hyg. and Occup. Med. 4:119*122 (1951). 10. Monsanto Company: Toxicity information. St Louis, MO (1976). 11. Edgewood Arsenal: Medical Research Laboratory Reports. MD. No. 256 (1954). 12. NIOSH: LimitingDosesAccording toRouteofAdministration to Experimental Animals Causing Death. Registry of Toxic , i Effacei of Chemical Substances. Vol. 1, 1977 Jsd p?: National institute for Occupational Safety dnd';,Health. Rockville. MD (1977). 13. Spector. W.S., Ed.: Handbook of Toxicology. Vol. 1, Acute Toxicities. p. 4. W.B. Saunders, Philadelphia (1956). 14. Gerarde, H.W.: The Aliphatic (Open Chain. Acym^^ Hydrocarbons. Chapter XXVIII in Industrial Hygiene W Toxicology. 2nd Ed., Vol. II. F.A. Patty, Ed., p. 1204. Interscience Publishers, New York (1962). 15. ACGIH: TLVs Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH for 197$. American Conference of Governmental Industrial Hygienists, Cincinnati, OH (1979). 16. NIOSH: Criteria for a Recommended Standard. . . Occupational Exposure to Diisocyanates. National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication 78*215 (Sept, 1978). 17. Stone, J.P. and R.N. Hazlett: The Transport of Hydrogen Chloride by Soot from Burning Polyvinyl Chloride. J. Fire Flammability 4:42-51 (1973). 18. Stone, J.P.: Transport of Hydrogen Chlorid by Water Aerosol in Simulated Fires. J. Fire Flammability/Combust. Toxicol 2:127*138 (1975). 19. Amdur, M.O. and D. Underhill: The Effect of Various Aerosols on the Response of Guinea Pigs to Sulfur Dioxide. Arch Environ. Health 75:460-468 (1968). 20. Amdur. M.O. and D.W. Underhill: Response of Guinea Pigs to a Combination of Sulfur Dioxide and Open H arth Dust. J. Air Poll. Control Assoc. 20:31 -34 (1970). > r CALL FOR PAPERS The 21st annual American Industrial Hygiene Confer nc . Tfoorr txhnee-1i 9o8o1f wiy/iiallvs9b4e-2h9.198lV,a^ ' ; ,, fP OR- /A-MrninieHncuRahii porms for submission of titles and abstracts for paperJs may b Industrial obtained from the Managing Director's office. American IndusHvaiene trial Hygiene Association, 475 Wolf Ledges Parkway, Akron, OH Yy 44311 (216) 762-7294. All abstracts must be submitted no later Conference than October 31,1980. Papers will be presented from the platform or in poster sessions. If the author prefers a poster session, this should be indicated on the form provided. Depending on circumstances, it may be necessary to assign additional papers to the p st r sessions, even though the author has indicated a pref r nee for platform presentation. 512 An. bid. Hyi Atsoc. L (*l) My. 1980