Document vQ57vavnnrwkj13xrmazQ6m

Mr. Harry B. Rhodes Union Carbide Corporation Mining and Metals Division P.0. Box 579 Niagara Palls, New York 14302 Dear Harry: As we discussed in our telephone conversation recently, I am enclosing a copy of a report dated April 17, 1973, prepared for Johns-Manvilie by Walter C. McCrone Associates, examining tremolite migration from food packaging materials. As you will note from reading McCrone's report, the results of the migration tests using the addressograph-multilith machine are not reliable due to an obvious contamination problem. However, you will note that McCrone found no tremolite migration whatsoever in meat samples wrapped or sandwiched in between paper containing tremolitic talc. We are presently conducting further tremolite migration studies using dry food substances, as suggested to us by the Food and Drug Administration. As soon as the results of these tests are available, I will forward a copy of our Research Center's report to you. If I can be of any further assistance to you in this area, please let me know. Richard P. Carter, Directdr Government Relations RPC/emr Enc. k 17973 UCC 007765 T' ' \ fl 1l-1 LA ^ Jolins jVUmvillc Products Corporation Greenwood Plaza Denver, Colorado 80217 tJ Cc t/7 L' EXAMINATION OF TRE MOLITE MIGRATION . Date; 17 April 197.3 MA Number: 3017 w Copy ^ of 8 A i 7 97 3 waiter c me crone associates, inc. 2820 SOUTH MICHIGAN AVENUE * CHICAGO. ILLINOIS 6QGI6 UCC 007766 EXAMiXTJON OF TREMOLITE MIGRATION Introduction Johns Manvillc Products Corporation produces two tale-based products, "CYCLO-FIL" and "CYCLO-SORB", which are used in the manu facture of food wrapping papers. At the present time there is concern over tire health hazards of asbestos, and since one form of tremolite has been classed as an asbestiform mineral and tremolite is a constituent of the talcs used in these products, Johns Manville are particularly interested in deter mining whether any migration or transfer of the tremolite in the talc may occur from the paper to the food skiff in normal use. Johns Manville there fore requested the assistance of McCrone Associates in determining how much transfer or migration of tremolite, if any, might take place. . Materials and Methods for Conducting Tests A number of samples of papers which had been experimentally produced for Johns Manville Products Corporation by the Department of Paper Science and Engineering, Western Michigan University, Kalamazoo, Michigan, in which different loadings of the products "CYCLO-FIL" and "CYCLO-SORB" have been used were provided by Johns Manvillc Products Corporation. "CYCLO-FIL" and "CYCLO-SORB" are trade names for commercially produced talc (hydrated magnesium silicates): "CYCLO-FIL" contains 20-30% tremolite and "CYCLO-SORB" 2-5% tremolite by volume. Also provided were portions of Scotch Tape with adherent particles which had been obtained by running GOO sheets of the experimental paper through a lithographic machine with a water-wet roller. The pliilosophy behind these tests w s that the wet roller would pick up any migrant tremolite particles from the paper surface, transfer them to the roller, and thus, by stripping the dried roller with Scotch Tape, these migrant particles & 1 7 Q3C -i- waiter c. me crone associate UCC 007767 could be coIL.cl'-' !. O.i cue:; c roller wore st rf"' to give particle loading equivalent to that which would be obtained from superimposing 1500 sheets. A detailed list of the samples is giv:. i in Appendix 1 to tills report. Several tests were performed on these samples by McCrone Associates as follows: _ (1) The Scotch Tape was examined microscopically and particle counts were made on selected samples. The examination was performed using a 45X ob jective and 25X eyepiece to give a field of view 200 pun in diameter. The samples were carefully examined for uniformity of distribution of the particles then 5 fields of view were selected at random and the tremclite fibers were counted. Tremolite was identified by its optical properties and by prior familiarization with the appearance of tremolite under the microscope using a standard tremolite sample. . . . (2) Samples of the paper were sandwiched between meat slices, frozen and allowed to stand for several days. The meat slices were then un frozen, the paper carefully removed, and the contact surfaces of the meat were thinly sliced, mounted on microscope slides and ashed in a low-temperature asher so that the particulate material collected from the paper could be ex amined on the microscope. , (3) A number of samples of meat were wrapped in samples of the paper, kept frozen for several da37s, thawed, unwrapped, and thin slices were taken from the surfaces which had been in contact with the paper. These thin surface slices were then examined microscopically to determine whether any particles had been picked up from the paper. A i 793 1 2- - v/citer c.mccrone associ UCC 007768 Results , To verify that the microscopic identification of tremolite fibers was correct, samples of pure "CYCLO-FIL" and "CYCLO-SORB'* powders were examined and the amount of tremolite in each was determined. This examination indicated that "CYCLO-FIL" contained approximately 30% tremolite particles by volume and "CYCLO-SORB" approximately 5% by volume. These figures are in excellent agreement with Johns Manville Products Corporation's specifications for these products. Table 1 records the results of the examination of the Scotch j Tape samples. The results' are split into numbers of fibers greater than 5 pm and less than 5 pm. This figure was selected on the basis of the . O.S.H.A. regulations for airborne asbestos which excludes particles less than 5 pm. In most instances only about one-third of the particles are* greater than 5 pm. The total number of fibers is also recorded. Tlie control sample 2CC for the series 2CC, 2BC, 2A shows approximately three times the particle count as the other two controls, 1-Z and 2-AC, suggesting contamination during this series of tests. The series 2CC, 2BC and 2A is, therefore, not included in the discussion of the i results. Considering these results, it must be remembered that these represent a fiber loading equivalent to passing 1500 sheets of paper through the test apparatus, thus, even in the worst case, the wire side of the 100% "CYCLO-FIL" sample, the average number of fibers per field of view works out at about one fiber for each forty sheets cf paper. That is, the probability I j of finding a migrant tremolite fiber in a microscopic field of view selected at ! random from one sheet of paper is 0.025. Furthermore, the presence of tremolite fibers in the blank control samples, 1Z and 2 AC proves that some contamination has occurred. It is logical to assume that similar contamination o welter c. me crone associates, inc. A'i79SJ UCC 007769 . is also increasing the counts in the other samples, Thus, in my opinmv papers made with Ic. clof "CYCLO-FII." op to *!0". and levels of "CYCLO- SORB" up to 100% are substantially free from tremolitc migration when tested using the wet-test method. Several meat samples that had been in contact with the filled - papers were examined after low-temperature ashing. The samples which i 1 were specifically examined in detail were IF and 1G, both 40% "CYCLO- j FIL" samples, the latter with S% tub size starch; Sample 2A, the 20% j "CYCLO-SORB" material; and Sample R379, a presently available commercial j paper manufactured by LongviewFiber Corporationand containing 1.2% j "CYCL0-S0R3" -- a comparatively high level for a commercial paper. Tile meat samples which had been in contact with both the wire side and j i * the felt side of the paper were examined after asliing using a light micro- j scope at magnification up to 420X. Even though in some instances the . * paper had been completely saturated by the natural juices from themeat, there was no identifiable transfer of tremolitc from the paper to the meat. j j 1 1 j That is to cay, no fibers or particles identifiable as tremolite were observed. j Several small particles which were present were of a type which also occur \ in blank meat specimens curd are probably oxalate crystals which are fre quently seen in tissue samples. Finally, larger samples of meat were submitted to simulated ' wrapping tests. The object of these wrapping tests was to subject the paper to folding and handling stresses similar to those which it would undergo hr normal use and which might result hr greater degradation of the paper, and v lienee greater migration of the tremolite than would the sandwich tests j described above. After unwrapping these samples, thin slices were cut from I . the surfaces of the meat wliich lead been in contact with the. paper and were j examined microscopicallj\ Again, no tremolite was detected by microscopical j examination. In view of the earlier work, only the two 40% samples, IF, 40% } "CYCLO-FIL" and 2G, 40% "CYCLO-SORB" were examined in detail. . A i 7 9 3 3 -1- waiter c. me crone associates, inc. UCC 007770 Conchunmis ' . It is my opinion that no significant migration of Lrcmolitc takes place from papers in winch "CYCLO-FIL" or "CYCLO-SORB" are used as filler at levels of these fillers up to 40%. At the level of 100%, the papers made with "CYCLO-SORB" appear still to be stable, but those made with "CYCLO-FIL" show signs of degradation of the paper, as evidenced by numerous cellulose fibers appearing on the sample. Papers made with a pigment (G0% "CYCLO-FIL", 40% TiO^) levels up to 20% similarly show no significant migration of these fillers. . Respectrull}' submitted, Ian M. Stewart Manager, Electron Optics Qroup A .'7 98 4 waiter c. mccrone associates, ice. UCC 007771 Sample Monday, 10/23 1Z 1A IB 1C ID IE IF 1G 1H 11 1J Tuesday, 10/24 2CC 2BC 2A 2AC 2B 2C 2D 2E 2F 2G 2H 21 2J 2K 4A 4B 4C 4D appendix i Experimental Paper Sampler; Description Control Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil Cyclo-Fil . Cyclo-Fil Control Cyclo-Fil Cyclo-Sorb Control Cyclo-Sorb Cyclo-Sorb Cyclo-Sorb Cyclo-Sorb Cyclo-Sorb C3fclo-Sorb Cyclo-Sqrb Cj'clo-Sorb Cyclo-Sorb Cyclo-Sorb 5% pigment 10% pigment20% pigment 30% pigment 1% rosin, 2% alum .5% . 10% 20% 20% + 8% tub size starch 30% 40% . 40% + 8% tub size starch 80% 100% 200% ' . 0% size, 2% alum ' ' 20% 20% 1% rosin, 2% alum .5% 10% 20% 20% + 8% tub size starch 30% 40% 40% + 8% tub size starch 80% : 100% 200% Slurry of 30 lbs Cyclo-Fil - 20 lbs A - Ti02 at 2 lbs/gallon. 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