Document vBw8pKX5N1Q8GGBVbzzDBgjKY

FILE NAME: Union Carbide (UC) DATE: 0000 DOC#: UC066 DOCUMENT DESCRIPTION: Unpublished Internal Report - The Effect of Chrysotile Asbestos Additions to Cellulosic Paper 076677 1 w v r C T OF C m T S a r H S A S S " * ABDUIOiS TO CELU^CSIC P A C T I. INTRODUCTION in the previous paper the properties of a highly refined ohrysotile asbestos produet were disoussed. the three principal characteristics of this product that apply to paper applications ares 1. The surface charge - cationic 2. Particle shape - fibrous . j ( Surface characteristics - (a) organic adsorption (b) chemical reactivity . These properties differ sufficiently fran those of the more conven tional paper additives to indicate a promising potential for us. to the PaPr industry. In addition, refined asbestos is a material of lev cost and is available in sufficient quantity to supply a consumer a. large as the paper X t r y . Advances in processing techniques have Insured a uniform p r e s e t that can be supplied vlthin quit, rigid specifIcations. Wit- respect abrasiveness, radiometric determinations have shown that the pur.fi - . is considerably less abrasive than e n d i n g fillers or bleached .^Iflte P ^ P . The properties imparted to paper by addition of purified ,, W . U M paper-machine behavior, r e determined by experiments, worh t c " th.1 laboratory ami in full anal, mill t r U l a . * * . . . ` In this paper. ' - discussed H, ' ra b q r ^t o RY DATA .* The laboratory results, a. reported herein, were obtained in cur awn ` laboratories at Tuxedo, hew Torh, ami through th. effort, of Professor. - =' Jenn.es and A. J. C h e of th. University of Maine, who have ~ ' sultants during this program. Th. tests were conducted ^ Cl'*11* laboratory Noble and Wood handsheet machine and, unless ] \ 00\ used a bleached sulfite stoch beaten to a Canadian Stan d ^ d rreness =f .00 10 ml. If r Eandsheets were mad. at the standard basis weight of 60 grams per q tested, wherever applicable, cor d i n g to the TAPP1 standard pr o ^ d - 0766-7S ,, , . x . T f f w t . on Beten^ - The effeot. * Incorporating a highly . per vere found to b. - m i l leflWiUated Chry,0'a ' tlk'r isong m o r a l e additives. % self ratantion of . or titanium dioxide pigman . X, algnlfleant on a a i m g c * of eiectroposltiva surface charge, ^ ^ vh,B cempsrad vith clay rlff3re if chi. improved ratantion ^ ,, u m hare t i t ater pa. ratantion, the ^ -* * ~ cliy -- n r : rrr^ r charged material into a pape &ce of paper-making con- ts A summary of the rela. . individual motilities) components, a ,avnrtory measurements of inaiviau** atituents ( caleulated from laboratory me f were determined to "be: Bleached Sulfite Cellulose Titanium Dioxide (BA-50) Talc purified Chrysotil. Mbe.tos -lU. - 9 -19 None -15 +38 **5 JPH- 6> 5*0 10 6 6.6 6.6 5.0 ,, Accordingly> the chryaotile w a s t e s a f u m i a b oonatituant.. That this ^,,flocculate vith any and all of ^ ,,hen asbestos and TiOa ^ ^ , ribrou. titan! p l i a n t ere agitated togatbar * W o r l d , pigment. Titanium dtomid. ^ ^ ^ a mllhy ^ eon o = Culatl=n 1. that tenda to remain cloudy o achieved, the ater at the inter. the 1i02 is being held by the as es ^ ^ . n o c s ia d e a r . Thus, a d aerographs of the combined ^ ^ dispersed state and product (Figure 2) shov that the p ^ ^ fict that these floes are i. bald by the asbestos. ^ ^ ^ This should alio mmimum-affl- formed without agglomeration o d s n o y in obtaining its optical P U C P " * Th. advantages of asbasto. over eo ^ n o c c d a n t s , cither ASSTHAT /0 3 7 A & 7667G --------- - , - TM 3 1 -- " " 10 c h l l ^ s i c . pa k r Rotert G. Woolery* The effects of Incorporating a new, hltflr perl"! pit-free chrysotlle asbestos fiber In cellulose PE?' ^ t Llscussed. Data are presented fro* both laboratory handsbeet *> I t s and paper m i l * . =n tb. effect o f t * soth operational factors and on .beet properties. discussed include retention of ceUulos. flues d fl U e r s such .. TdOa, fb.en.ss, drying rate, pdtcb osss and opacity, softness, strength, porosity, prlntablUty, ,, d dye retention. Savings possibilities and otn 1an d iSCUSSed. tW * (BEPO. EXH.__L . ayjrl,.pI!*lir+*crrS:-:r-r-/- f'-.T;Trr^crr=ri : Oroup Deader - Prcd^Develc^ent d Technical Service. .. S i n g and Metals Division P. 0. Box 32^ , Tuxedo, New York IO907 /Ww, .... K I R B Y A. *'NDY 076673 5. Inorganic or organic, arc two-fold: < U retention without agglomeration, ani (2) floe stability. Experience haa shown that no degradation of the floe occurs even after repeated agitation. Once formed, these floes are stable even under prolonged high-shear agitation of a Waring Blendor. laboratory studies have shown asbestos to be compatible with all types of organic and polymeric flocculants. In a furnish of high filler content, particularly, the combination of asbestos and coagulant is especially effective. Usually the net effect is greater than can be achieved by either alone. Data from laboratory tests run on handsheets to demonstrate the re tention properties of chrysotlle fiber are shown in Figures 5 and h. The con trol series for this evaluation were made with 1* clay. Where asbestos was employed, it was substituted on a pound-for-pound basis for clay, so that at equivalent retention the ash and opacity values would be comparable. The level of TiOa addition was then varied from no TiOa to 10* added based on the stock. It is apparent that the retention of the additives la greatly improved with as little as 2* asbestos. Clay retention is also greatly affected. Because thesedata are based on .ingle pass retention values, the value, are quit. low a. can be seen in Figure t. Since this is probably the most difficult retention con dition, the effectiveness of the purified fiber is clearly demonstrated. In another series of tests, run under similar conditions but with high levels of clay, the results were equally encouraging. The ash l u e s for levels of clay additions ranging from 25* to 50* show that the retention of the filler is Increased with increasing asbestos additions up to 6* asbestos (Figure 5). The effects of white water recirculation on the ash content of the a h M t were also determined ami are shown In Figure 6, Whereas the average ash retention only reached about hi* with a one pao. circuit, with recirculation the average retention was Increased to 70*. There is also evidence that equili brium was reached in the recirculation system at 3* asbestos whereas it r e q u i r e about 5^ for the single pass systea. 2. Effects or. Cnaclty - Inasmuch as chrysotlle asbestos has an index of refraction of 1.52 - 1.55 that is similar to that of kaolin, it could b. expected to have equivalent opacifying power. On the basis of the amoun. added, "asbestos-filled sbee-.s showed higher opacities, however, as is shown in - Figure 7, the opacities sre essentially identical at corresponding filler weights in the sheet. In the series where asbestos was substituted for 2, clay 076630 t. ln . titanium dioxide filled sheet, the resulting opacities associated vith L asbestos .re invariably higher. In Figure 6 , the average opacity in- ere.se is Iron S to 3 Points. This is attribute to the increased retention of all components through the cationic charge of the ohrysotile asbestos. 3. Effects on Tear and Tensile - The comparative tear values for the addition of either clay or asbestos are similar. For both minerals, small Quantities are beneficial whereas larger quantities prove to be detrimental. Figure 9 shows that small quantities (< 5*) of asbestos r e f u t e d in tetter tear "factors. Above 5* asbestos additions the tesr factor decreases below that for clay-filled paper. This effect is probably due to the geometry of the fiber as veil ,, to its smaller particle size. Asbestos is more efficient at disrupting the hydrogen bonding of the cellulose fiber than arc non-flbrous minerals. An even better example of the geometry effect can be seen in F i g u 10, where _ < tensile values are shown for corresponding filler content of the sheet. Onde 3* filler in the sheet is exceeded, the effect on tensile strength is influenced considerably m o by the asbestos then by either Olay or T10a . fc e r e c t s or. Softness - While the strength of the sheet is reduced by asbestos content, a corresponding softening effect is also achled. This relationship 1. shown in Figure 11. In a light-weii tissue sheet a * * . content s u i t e d in doubling the softness value, obtained on a Clarh * - Stiffness tester. Various furnishes w e Investigated and all types appear respond in a manner similar to the light weight sulfite furnish. 5 . ycc.ee. on Pule Freer-.. - A. might be expected from the use of . nail sized, fibrous filler, the freenes. of the furnish is affected. The degree to whieh the asbestos slow, up the furnish drainage appear, to be d.peud- e n f o n the original freenes. of the stooh. For example, the data " show that the lower the freeness of the stooh the less it is At the low levels of asbestos additional normally used in paper this has not been a problem ln the mill. A. "Effects on Porosity - With the incorporation of the highly f i n e d asbestos the sheet porosity Invariably has a tendency to decrease with increasing asbestos content a, shown in F i g * . " ; " f -- porosity values obtained by the addition of between zero and 2* * attributed to the retention of fines. This effect n o m a l l r accompanies tion of ohrysotile asbestos. 076681 7 . *----- on Printahlllty - normally, any tin. the porosity of the sheet Is reduced srd the formation of the sheet Is p r o v e d , the printsbillty is subsequently benefited. Printing .relations by the Research Instltute for the aerican Newspaper Publishers' Assoolstlon of samples obtained from the various Bill trials verified these conclusions. Where sheet contain ing asbestos vere compared to the control runs on the sane grade, improvements in the following properties were noted: 1. Smoothness . 2. Opacity 3 . Ink Transfer if. Printability In most cases, improvements were noted for both the felt and wire sides. Usually the more significant improvements were observed on the wire side thus demonstrating an improvement in two-sidedness. ; 8 Ejects of Stock Type - Some data have been obtained on fur nishes employing stocks other than a bleached sulfite stock. For the most part the data obtained were consistent with the results repor.ed so far. The mo notable exception was in a typical newsprint furnish of ft* grcundvood - 2 0 , bleached sulfite. Under these conditions, as much as 6* asbestos in the s ee caused no appreciable reduction in the tensile strength. This probably can attributed in part to the inherent weakness of the sheet and, in part, o e retention of the groundwood fines which contribute to the sheet strength. 9 . r**- Applications - Probably the largest single application for asbestos, in addition to those already described, is as a pitch controlling agent. Laboratory studies have been conducted on a-wide variety of pulps, u . because of the diversity of pitch problems, no universal data are obtainable, in the majority of the cases, however, asbestos has proven to be more effective than other'cotsaercially available products. The total reduction in pitch is generally oniy slightly lover than competitive products but the amount o as es tos necessary to reach this level is usually significantly less. ^ Considerable laboratory effort has also gone into the retention ot -. ft,, commercially available latices are beater-additive latices. Since most of the co=:erciai-y anionic, they have proven to he e n t i t l e vith the oationlo ohrysotl^-_It h. been found advantageous to blend the asbestos vlth the oeUulose first n order ' to put the asbestos or. the cellulose m a dispersed state.-Thus, when the latex 076682 6 ,,,,_ly throughout the furnish and nlalnlMS the u died 1 1 deposited m i . * J ^ ^ undesirable In the finished tendency to form the late* l8g-" universally " ?r0''ei 8114 the sheet* The o v e r a U f o m d to he e ^ - e d (particularly .t resulting Physical properties ha attributed to the inproued tecs 11* and fold) to a higher degree than can late* retention. Studies in dye retention generally strove the retent on particularly true 1 t h J lb0UB that 24 asbestos addition 111 th. tuo-aldeness. This Is It has also been possible to directly to the f u m l s h and Hsults in a close control f ^ " ^ a l T s o discovered in the field of con- A rather unique applicatio the sheet formation ductlve paper. I - a c t i o n in J - " provide a m o v e ^ " "^ 1 flocculation. Again* tion are found to be In the 2-54 range. ^ **"+ b ' required for this appllca- m . mjll TSIAI. Pg A .,,.thing in excess of 200 mill Since th. beginning of this progren, s ^ - h l n g ^ ^ trials have been conducted. ft the ^ J o r l j o ^ asbestos baa perf u m e d as p m d i c d fro on machines where mineral add fte,, developed due to the addition o ^ * addition, ,, M r l e ua problem have here been conducted board. A review of some -of these t-riatls de-montstrates wa , chryeotlle fiber. 1. Retention - . 1x1 a paper, 54 asbestos..ubstltuted ^ ,, ,W 3i chay r . ^ requirement from l4 5 I b a / t o ^ O W ^ lb. opaque printing a reduction of the TiOa ^ ^ previously Iromthe c a d as * specifications of the sne.eu h o u t machine problems. A a u m a r y of theae . Condition 1 (control) 2 3 k ,* C l z y k 1 1 1 * Asbestos 3 3 3 * Ti02 8.25 7.0 6.0 6 .0 * Glue 0.25 0.25 0.25 m Opacity 89.5 92.5 91. 91. In another trial, on a 37 lb bond paper,- 2 * asbestos was used for a corresponding amount of clay. Titanium dioxide amounting to 2.5* of the furnish vas also going into this sheet for opacity. A summary of these results follows: Condition Pre-trial 2* Asbestos Added Post Trial Opacity 82.5 83.5 82.0 PAPER ANALYSIS * Ti02 1.6U * Ash 12.0 2.20 13.9 1.75 . 12.2 Ti02 Retention 65.5 88. a 70. These data show an improvement in Ti02 retention from about 68* to .88* with a 2* asbestos addition. .In addition, the saveall effluent was monitored during both the control and trial periods. The average solids content during the pre-trial and post trial period was 2.3 pounds per 1000 gallons. During the trial the solids con tent was reduced to 1.5 lbs per 1000 gallons. Due to the improved efficiency resulting from the asbestos, a 35* reduction in eolids loss was realized. It is not unusual to expect saveall efficiencies improvement during these trials. In one trial, particular attention was paid to the saveall unit since it had been operating under a heavy load with a low efficiency. In this ' instance both the influent axd effluent were monitored. A summary of these data follows: 07668.! Seveall - fits solids/lOOO gal.) rendition pre-trial Influent 17.9 Effluent t.36 Saveall Efficiency During Trial (2* asbestos) 1 .0 hr. 2 .0 hr. 3 .0 hr. Post Trial It .3 13.2 11.0 2 1 .t 1.15 0.90 0.71 6.00 Average: Without Asbestos 1 9 .6 t 5.18 7t* With Asbestos 12.83 0.92 93* Reduction in Solids resulting from the use of Asbestos 35* 82* 2. Softness - A natural application for the highly refined cbryso- t U e fiber Is to the tissue ami towel grades. This mtoerel Is unique e. an inorganic softening agent. Numerous 111 trials have demonstrated Its ability to impart both softness and a velvety hendfeel to both tissue and levels. A typical relationship between asbestos content and Handle-O-Met.r value, on a bo pound towel Is shown to Figure lb. The levels Illustrated, up to 5* asbestos, are typical of the levels used for this purpoae. For this grad, a 5* asbestos addition reduced the Handle-O-Meter values iron a control of 27 to 17. In a -- - trial on a 13.25 lb tissue, b* asbestos was added to improve softness >1 handfeel. Ihe furnish consisted of 25* Fine, 0* Hardwood, and 15* Broke. The effect, on Handle-Mister values were as follow, i , Condition Control T r i a l --- * Average of 6 reels ** Average of 8 reels h a h d l e -o -m s t e r v a l u e s MD CD 15 * 9 ** 22.5 11.5 Not only was a slgnlfleant Improvement In softness realised, but the level of difference between machine direction and cross-macStoe direction was reduced by nearly 505. This 1. probably due to the p r o v e d sheet formation. Tn addition to these improvements the improved drying rate of the asbestos- filled tissue resulted in a lover steam requirement to the Yankee Dryer. By virtue of the inherent physical properties of chrysotile asbestos vide variety of applications to the tissue and towel grades have been ex plored. Its largest single application at this time is as a tool to achieve quality in a vide variety of furnish components. In mills where the use of coarser and harsher cellulose stocks (or even waste paper) is limited, the incorporation of asbestos has permitted a higher percentage of these cheaper and coarser pulps without a loss in quality and at a significantly reduced furnish cost. For still another mill, where the drying chain controlled the machine speed, as much as 30 to 50 feet per minute increase in machine speed was achieved with a 2$ asbestos addition, a situation considerably more economical than the standard furnish at the slower rates. - ^ 3. Pitch Control - The most universal application to date is id pitch control. In mills where this use has been investigated it has been found to be more effective than other commercially available products. Where asbestos is currently being used it has replaced talc, at the ratio of 2 lbs. of asbestos per 3 Its. of the competitive product.IV. IV. CONCLUSION These studies have shown purified chrysotile asbestos to be unique as an inorguilc additive to cellulosic paper. Onlil. other paper components this material is c.tlonlcally-chnrged 1, as such, performs as a retention aid to .11 constituent. in the furnish. It. uniformity, small Petiole sis. and fibrous geometry contribute to the softness of the sheet ami improve tvo-slded effects. .Use h i * surface urea and its adsorption of organic, aid in dye adsorption and printability. Its performance on the paper machine has been most satisfactory usi, as a rule, has caused no problem in the subsequent processing of the paper, her. care has been used to employ a sufficient quantity of asbesto. to be effective, yet not s o T S r t * & * - . strength of the paper is degraded beyond reasonable limits, the results have been quite successful. Because of this'v.rs.tlllty ve believe that purified chrysotile asbestos ill continue to grov In its present plication to the paper industry . and that nev areas ill develop vhere the unique properties of this material will be advantageous. 076 ACKUCELLED SCENTS I am greatly Indebted to Professors L.C.Jenness and A.J.Chase, of the University of Maine, for their . collaboration, guidance, and laboratory data throughout all stages of this project. Thanks are also due to Messrs. B.L.Ingalls and G.L.Dickson, of the Union Carbide Corpora tion, Mining and Metals Division Research Center, for their assistance in obtaining the data that have been used in this paper; to Dr. S.Chvastiak for the electrophoretic mobility data; and to the many members of the laboratory staff who have helped through their advice and encourage ment. FIGURE I : Co-flocculation of purified chrysotile asbestos and titanium dioxide (electron photomicrograph,, magnification = 15,9 0 0 X ). 07662 PERCENT ASH IN SHEET * 2 4 6 8 -PERCENT T'i0 2 ADDED FIGURE 3: Ash content vs. percent T i0 2 added, with and without asbestos. 0766"" PERCENT ASH RETENTION FIGURE 4: Effect of basis weight and percent T i0 2 _ r\ n e k rotontinn w i t h nnd with** PERCENT ASH 3 7 l b s / 3 0 0 0 f r Basis Weight Sheet r 076631 3 FIGURE 5: Effect of asbestos additions on osh content in highly filled handsheets. AVERAGE PERCENT OF FILLER RETAINED FIGURE 6: Average filler retention vs. asbestos - additions. 0 7 6 rr-I.rSyj FIGURE 7: Handsheet opacity vs. filler content. PERCENT OPACITY 076S94 FIGURE 8: Opacity gain vs. percent TiOg added, with and without asbestos. . FIGURE 9*. Tear factor vs. fille r content. 076696 FIGURE IO: Hondsheet tensile strength vs. filler content. CLARK SOFTNESS VALUES 076697 FIGURE H: Handsheet softness vs. asbestos content. CANADIAN STANDARD FREENESS-m l r 07-669 S FIGURE 12: Furnish freeness vs. asbestos content. .r 2 4 6 8 PERCENT ASBESTOS ADDED FIGURE 13: Handsheet porosity vs. asbestos content. er 075700 FIGURE 14: Towel softness vs. osbestos content. > i 076701 PBOPEMISS n r tSSSTO S SUIT.ABIS FOB USE DT CELLtJLOSIC PAPEB A. V. Nauaann* ABSTRACT Chrysotile asbestos is now available in a highlypurified, grit-free fora, non-abrasive to Fourdrinier wire and printing plates. Its chemical and physical structure and proper ties are described relative to the geometry of cellulose pulp fibers. The electrostatic charge properties and surface chemistry of chrysotile in water systems are also discussed in relation to other materials found in paper furnishes. Union Carbide Corporation, Mining and Metals Division, Tuxedo, New York, .IO987 k ieiL L d e po . ex h . - 3 - zfiofe-n KIK".Y A. KEKKDY COURT BtPCRTER J . / /T 7 * fKIRBY A. iC'/MSrv COURTT 5-*" 076702 Asbestos is less m m tor several naturally occurring fibrous Blnersls. Tbe most ccocon, and the one that Is finding lncressm g use os e paper additive, Is chrysotlle, Ka(CH),Sl,0io The purpose of this peper Is to Caspars ehrysotlle properties vlth those of other commonly used additives. CRYSTAL STRUCTURE AND PARTICLE MORPHOLOGY Chrysotile has a structure like that of the kaolinite minerals (l) in that the structure consists of an alternate series of layers of tetrahedrally coordinated silica and octahedrally coordi- ^ nated magnesium Joined into a composite sheet, vith the tips of the silica * tetrahedra and one of the surfaces of the octahedral layer lying in a common plane. The silica layer is in oxide form. The magnesium layer is in a hydroxide form, giving this layer a resemblance to the mineral brueite, [Mg(0H)a}. Figure 1 is a representation of the structure, the "a" dimension having been exaggerated to show the details of the structure. Pauling (2) predicted, before the layer structure of chryso tile vas recognized, that a magnesium analog of the kaolinite minerals vould have to exist as curved sheets because of a mismatch in tbe ^ repeat distances of the individual layers. The normal repeat dis- ^ tance for the silica layers (8.9A), as found in kaolin, is smaller 'than the corresponding repeat distance of an octahedral magnesia sheet (9.hA), as found in t h T S e w r i l T B r u c i t e fc>. Pauling's prediction has been abundantly verified by x-ray diffraction studies and by electron 076703 r u.W). ~ i * * -t " *" ^ r s of . *-- * -" " r" 10' 1118 pErtllUy 0118 fUll* m t - l l t o m of cfarysotlle B o o t e s that mehe. t. useful - ^ t i v e to e peper furnish. An 1 = - lercgraph of typical ohryso- tile fibrils is given in Figure 2. As is shown by the calibration marks, the individual chryso- U l . fibril, sx. .rmaely small; t h o u s e s being needed to m * e ,, the eshesto. f l i g h t , vlslhl. to the ^ e y i **" fr0B . fe. microns to many tens of microns. -- *-- ^ ere in the range 250 to 55OA. As the f o l d i n g data iUustrete, this is e site considerably belo that of u s ? materials normally oonsl- dered to be of small dimensions. Material Rock Wool Synthetic Organic Fibers jTmwm Hair Paper Pulp Fibers Kaolin TiOa Chrysotile Typical Diameter " (microns) 1-20 lO-UO approx. 1+0 10-30 0 .2-10 0 .2-2 0 .025-0.035 *r 076704 The usual mode of occurrence of chrysotile is a "cross-fiber" configuration In vhlct ftl-nt. of chrysotll. (l.e. undies of fibers) ,, e closely packed together and set at right angles to the vails of cracks and fissures that extend through the host rock of the ore body (6). liberation of this material Is accomplished by repeated crushing and classification operations (6). The resultant products, particularly the less expensive grades, contained up to several percent by eight of rock fragments and other abrasive constituents; and, for this reason, are not veil suited to use on the high-speed machinery used in the paper industry. In 1959, an unusual deposit of chrysotile asbestos, vith properties and mode of occurrence that differ from those of cross-fiber material, vas discovered in central California (T). The ore of this deposit, instead of occurring in veins, occurs in randomly-oriented, matte-like flakes and agglomerates that are not associated vith the hard, consolidated rock masses characteristic of cross-fiber deposits. The ore is of high grade and is therefore amenable to different processing procedures than are usually used vith conventional chrysotile ores. Specifically, vet-processing procedures have been developed that give rise' to high-purity asbestos products, essentially grit-free and of high brightness. vn 076705 TraASIV5!SS OF CEHYSOTILS PRODUCTS The measure of abrasiveness commonly used In the paper industry ls the Valley Abrasion Test. Essentially, the method consists of rubbing . section of Fourdrlnler vire with a Mloarta bloc* in the presence of a ,lurry of the material under test. The slurry Is introduced at the inter face between blodc and wire. It then flows through the wire to a receiving vessel from which it is recirculated to the Interface. The results of the test arc reported as the "Talley Abrasion Value" , corres- . ponding to the weight lost by the wire in miUlgrsms. Unfortunately, the Valley Abrasion Test does not work well with fibrous materials, since fibers arc retained on the Fourdrini.r wire and do not recirculate freely. A radiometric-tracer method was developed to circumvent this problem. The details of this method have been given elsewhere (8); but, basically, it consists of measuring the amount of radioactivity transferred to the particles of a suspension, from an Irradiated Varlng-Blendor impeller, during a prescribed blending period. A comparison of the abrasiveness of wet-prooessed Kid conven tional dry-processed chrysotile products, along with data for bleached- aulflte paper stoch, 1. given in Figure j. The data point, of this figure, which establish the correlation between the Valley and the radiometric methods, are for a group of nonflbrou. . p i e . for which Valley Abrasion Values were a v a ila b le ;--Court-race ranges observed for samples of the 0707013 ' -a nn tins correlation curve, and the . materials are superlnposed on tins c fibrous aaterl ^ actual count-rate ranges for ViU,y abrasion values Inferred. The no gaterisls of the different types were: Count Bate (counts/nia) Wet-Processed Chrysotile Products Bleached Sulfite Paper Stock Dry-Processed Chrysotile Products 500 to 15 2,000 to 2 ,700 2k,000 to 78000 r , materials vere oleexly much less abrasive than The vet-processed naterlal . s em fact, vere less abrasive then paper P - r conventional products, and, In f , eased materials, therefore, vould not be expected to cense Tb, vet-processed nater! , fouririnl.r vlree, excessive ear to Btal surfaces such a. those of To trlnnine knives, printing plates, etc. rtsvrrn. Sim onvSICM. PROPSBUgS It vlll be shewn In the follovlng P T lS " unusually versatile paper active. ~ properties that n * e this possible axes ,, 1. el.otro-po.ltlv surface c h ^ g e In the pi r s e where nest papetnaking e ^ ts 5,rt* . . ~ . 2. highly anlsodlaenslonal particle shape x high surface area 5 Cb^ctll. fibrils ere of Colloid^ hv virtue of their small ^ ^sical dleneters; snd, when suspended in vat , , rules Of hydrophobic colloids. That Is, the fibril, electrokinetic rules of nyarog . 076707 develop a surface charge vhen suspended in aqueous solutions as a result of an adsorption of "potential-determining" ions from the suspending jnedium. With chrysotile and other oxygen-containing materials (metal silicates, oxides, hydroxides, etc.), the potential-determining ions are H+ and OK*. For a given material, adsorption favors hydrogen or hydroxide, depending upon pH. Chrysotile, by virtue of the magnesium hydroxide layer exposed at the surface, has a strong preference for the adsorption . of hydrogen ions. Chrysotile surfaces retain hydrogen and display a positive charge in the range of p H j g J a J g (2,10). Most materials (includ ing cellulose and the mineral fillers commonly used in the paper industry) carry a negative charge in neutral or acidic solutions. Typical values for the electrophoretic mobility of cellulose and of representative fillers are given in Table I. The significance of the charge of chrysotile fibrils, from the standpoint of the retention of fillers and cellulose fines, is obvious. Having a mutually coagulating.system of oppositely charged particles is clearly desirable. Electrostatic attraction, however, is but one of the factors that influence the effectiveness of chrysotile as a retention aid. The cylindrical shape of chrysotile particles is equally important. Colli sion and coagulation rate in suspensions of solids follow an expression of the fora (11) K D R na where D * particle diffusion constant R particle radius of influence a m particle concentration To a first approximation, R (the collision radius of an anisdimensional particle) varies as the longest dimension of the particle; vhile D (the diffusion constant) varies as the mean particle dimension (11). The net result, for the rod-like particles of chrysotile, is a large effective collision radius and a large diffusion constant. It has also been estab lished that coagulation in polydisperse systems (i.e., systems containing particles of differing sice) proceeds more rapidly than in monodisperse suspensions (11). These factors combine to give a high probability for collisions, not only betveer. chrysotile fibrils, but also between the fibrils and other particulate natter. Thus, in a paper furnish, chryso- t tile simultaneously acts as an effective "getter" for small particles such as pigments or cellulose fines; and is collected itself, either by the fibers of the paper pulp or as tenuous asbestos floes. With either mod of collection, mac rose epically uniform distribution of chrysotile, and of materials collected by the chrysotile, is obtained. The electron micrographs of Figure h, which are of surface replicas of handsheets pre pared with and without fillers, show the distribution of asbestos and TiOa on the surface of a pulp fiber. . * The electron micrographs of Figure k are of further interest with regard to the mechanical properties of paper. The strength, of paper is attributable to the combined effects of four factors: (1) the strength of the pulp fibers, (2-)-the- strength of fiber-to-fiber bonds, (3) the fraction of the fiber areas involved in bonding, and ( M the over-all distribution of bonds as determined by sheet formation (1^). The adsorp- 076709 tion of chrysotile fibrils onto palp fiber surfaces will have little influence on the strength of the fibers, but may have considerable in fluence on the bending between fibers. It is now generally agreed that bonding in paper is due to the formation of hydrogen bonds at fiber-fiber . contacts, to secondary valence forces of the London-van der Waal's type. Both types of bonding are of short range nature. London-van der Waal's forces decrease as some multiple power of distance. Even for interactions between large particles, where the additivity of forces extend their operative range, the forces fall off rapidly in the first few angstroms and are practically non-existent beyond 100A (lM* t Typical hydrogen bond distances are 1 to 2A (15) The diameters of chrysotile fibrils (approximately 300A) are long compared to these bond distances. This is not to say that the fibrils act as inert spacers, separating pulp fibers by JOOA; for chrysotile fibrils have OH outer surfaces that can enter into hydrogen bonding. Also, pulp fibers are pliable and deformable to a degree, and can expand to fill in the spaces between chrysotile fibrils. But the net effect is to reduce the total attraction between pulp fibers. It has been found, for example, that chrysotile additions to paper result in lower tensile and burst values, nd it,n r *priruHrigTy improved tear factor and softness. Practical applica tions of this effect-- to improve the softness of tissue and towel products-- will be discussed in the-paper-that follows. As would be expected frem geometric considerations, chrysotile hg a relatively high surface area. BET nitrogen values for wet-processed asbestos suitable fer the taper industry fall in range 50 to 60 n^/g. As 076710 is evidenced by th rather extensive use of chrysotile as a reinforcing filler for plastic and resin system, chrysotile surfaces have an affinity for organic materials. Use can be made of this property to adsorb soluble organic matter. Adsorption occurs not only for negatively charged molecules (anionic dyes, organic acids, etc.), vhere electrostatic . attraction can be used to account for adsorption, but under favorable conditions can also occur with cationic species. The adsorption of methylene blue from an aqueous solution is given in Figure 5* Dye concen tration in solution was extremely low until surface saturation was reached, indicating an extremely favorable distribution between the'sur- ^ face and solution even though a positive ion and a positive surface were involved. In the paper that follows, examples will be given where the . adsorption properties of chrysotile have been used for specific applies- tions such'as dye retention, improved printability, and pitch control. Another property of chrysotile that may be of interest for paper applications is its chemical reactivity. Chrysotile is inherently a basic (alkaline) material because of the brucite-like layers that are exposed at fibril surfaces. It has been shown that the solubility and reactivity of chrysotile suspensions are,.to a first approximation, similar to those of magnesium hydroxide slurries (16). It is also known , that acid gases in the atmosphere and the acid nature of sane of the constituents' of paper (alum and chloride residues from bleaching) shorten the u s e & l life of paper. It is reasonable to expect that chryso- tile would provide a reserve of alkali which would adsorb and neutralize these acids, and thus would contribute to paper's permanence and durability. I 076711 la suanaiy, the shape and composition of chrysotile fibrils give rise to a unique combination of chemical and physical properties tbat should make chrysotile an unusually versatile paper additive. Non-abrasive chrysotile products are now available in quantity, permitting their evaluation for specific applications. ` r 07672. 15 acknowledgments The author wishes to thank Mr. Wolbert Roettgers for the preperation of the electron micrographs of this comunlcatlon. 4e. 0.95A Ur*rt?iiv(ii b* HYDROXYL OXYGEN m a g n e s iu m O SILICON 'f 0 .0 6 A FIGURE I: Chrysotile structure (fter Whittaker). . Q T iS iO FIGURE 2: *r Electron micrograph of chrysofle fibrils (I5 ,9 0 0 X ). * PTTTTT COUNT RATE, counts per minute 0 7 S Y XL- f ig u r e 3: Abrasiveness of chrysotile products. UNFILLED HANDSHEET FILLED HANDSHEET O si a) I FIGURE 4 Electron micrographs (1 9 ,9 5 0) of surface replicas of handsheets nVr TASLS I Material Kaolin (Hydrite UF) Talc (Mistron Frost) Titanium Dioxide (Titanox AWD) Bleached Sulfite Paper Pulp Chrysotile IS 6.2 6.6 6.1 6.h .6.2 Mobility micron/sec per volt/cm . -1.^ -1.1 -l-1 -1.0 +3-1 Data vere obtained by the micro-electrophoresis technique described by Riddick (12)- UNION CAR 0 768 3H Asbestos as a Kealth Hazard in the United Klnadon by . C. Savers AUDYS DIVISION . s o r ~ ' o a ' r*/*0>T - 2- 0768*0. SUMMARY This report has been written to show the concern on tos grounds of those people involved with asbestos in the t Descriptions are given of the attitudes of the various approached. Action taken by Union Carbide U.K. person recorded. Up to date information is presented, and it. are discussed. Attention is,brought to a formal request made by the P Research Unit, Penarth, S-Wales, for assistance with t programme. The recommendation is made that Union Cart offer its facilities for trace element analysis of the Samples, assembled under the auspices of the U.I.C.C. *j y __ .._ -5- INDEX 076841 1.0 TrraoDUcnoN 2.0 WTSTORICAI STOWABY ' 2.1 General 2.2 Paper 2.3 Other Applications 2.4 Dockers J.O ACTION TAKEN EY UNION CARBIDE. 3.1 Visits 3.2 Dockers 3 .3 Literature Surveys 4 .0 inform ation acceded 4.1 Diseases Associated with Asbestos 4.2 Asbestosis ` 4.3 Bronchial Carcinoma 4.4 Mesothelioma 4.5 Aerodynamic Behaviour of Asbestos Fibres " 4.6 Standard Samples 5.0 RgQLTgFT FOR ANALYTICAL ASSISTANCE ? 6 .0 DISCUSSION * 6.1 Moral Issues 6.2 Expected Rise in Asbestos Diseases 6.3 Threshold L im it V alue 6.4 Similarities between Different Chrysotiles 6.5 Fibre Aerodynamics 7.0 RECOMMENDATIONS 7.1 Dust Counts 7.2 Analytical Assistance . 4 4 5 6 6 6 6 7 8 8 8 8 9 11 12 13 15 15 15 16 16 16 18 18 18 19 r ; &/>.>  4 07654: .0 rargODUcnOS . Union Carbide U.K. Idolted bieom^eMiWly1 " Just over two yeere. *" :*-Jets',,eocuted with the us. of this newrlei. k \- r r s ^ s -- ^ ^ s ^ -r ;x s s 5 .2 ii-- so fer. over 20 potential . ! ^ I ^ l ^ t 1 a ^ * ^ ' 0*"^ s \ s ; : w s : ; * & e s s - * '- 1*1 ' objectlona^ere the prim, reeeone for the reluctance. Carbide*e repli. have been baa, upon th.tvo conoonicetlon. *r Office on March 22nd. 1966. ^andet0 " T*^i in alleviatlns some of "Asbestos Toxicology Report . Oieso anxiety. However, there 1= a Stowing feeling feell-j that the quoted "Ihreahold overlU i,c* of k s s s j s s *. ^ of the information gleaned fro. several sources. grg-Q?zcAt. sx-yx? x , . *:*: It is possible that r*lle " * ^ S ^ ^ i i c ^ s S s i l s e d the worh' ' article in the Sunday Tines (3-** * Hospital. These two workers had . ' of Newhouse and Thompson at the e q u a t e d an epidemiological over approximately JO years. 7" * positively diagnosed diffuse ^ of exposure to asbestos was obtained m patients admitted to the hospital ^ and 8 female) had nritor.*l mesothelioma. Evidence q of Jue 76 cases whose background histories could be accurately traced. ^ . w . .h. nse-4Ption was given of a docker s . It was also ir. this article t**a^ ^ h*h wife who died of mesothelioma, and 1 contact with asbestos had n ' ^ example has become a " *5bv outmoded Asbestos Regulations -5 - 076&43 of new eases of most types of pneumoconiosis, but for asbestosis the trend is still upward. Shown below are the number of diagnosed asbestosis cases over the years 1960-64. * ' I960 * Number of Cases . 29 1961 43 1962 52 1963 67 1964 83 ' The Ministry of Labour is now actively engaged in formulating a new code of regulations, which this time will be more stringent and will include pipe '* ` laggers and dockers, both of whom were excluded in 1931* TO date, about 500 cases of cancer of the lung and mesothelioma are known to have occurred among people exposed to asbestos dust in the U.K. This may seem surprisingly small when it is realised that 25,000 cases of carcinoma of the lung - largely due to smoking - are diagnosed in this country every year. - It is pointed out, however, that it is only recently that d o s e attention has been paid to the problem. It is therefore " inevitable that an urJciown number of cases has escaped detection. * Only 3 or 4 mills in the U.K. are bona fide asbestos users. Probably wlth these mills specifically in mind, the Paper and Board Makers Federation sent a circular to its members last fear. This stated that the Minister of Social Security had made regulations (invoked in 1966) which allowed for compensation to be granted to persons suffering from a number of prescribed diseases. One of these was "diffuse mesothelioma . This publication caused a number of questions and doubts by several mills engaged in the evaluation of High Purity asbestos. The following examples exhibit the approach to the problem taken by some of the British mills. 2.2.1. Southalls. - makers of cellulose wadding for sanitary applications. Jis"wXs"the first mill to challenge our material iron a toxicological standpoint. They ran a 2-day trial at the end of 1965 and-showed , some technical advantages. They refused, however, to proceed further ex they calculated that there would be at least 2 lbs. of airborne asbestos produced each day at the creping doctor. 2.2.2. Charles T u ~ ! ri " rtv *1 of Southalls. ttereping doctor and cutters. Also worried by dust hazard 2.2.3- Tullis Bussell. - the laboratory personnel were advised to wear masks when evaluating High Purity asbestos. Nevertheless, failure to run a .rial so far is probably attributable to indecisive experimental work rather than trepidation as to toxic hazards. 2.2.4. iford Pacer. - ' ran . trial f *y> *f" r f 311;;* " i!* u n - b k r t c i il . The .111 safety officer was present. and asked tral (icalnly unanswerable) questions, as did-a nuaber of t..e ratlves. Present .111 policy la to run the next trial wnen the h.as been 'forzotten. -6 - 076841 2 2 5 Reed Croup. - showed concern 9 months ago. Their Medic !o S s ! t e d t h . Chemical Health Officer and sent a letter t mill, who were intending to use asbestos. He stated that - opinion, the amount of asbestos used (less than 26 in the was too small to be a hazard to health. 2.3 Other Applications. . . ' Market development in fields such as caulks, sealants., and polyesters is still in its infancy, and is currently very ac these applications it has been necessary to o.-er the open grad^ because few manufacturers have sufficiently high shear devices w the compacted pellets. All manufacturers are aware of the probable ^ bazards. espec already utilising asbestos in some o t th e ir *TMducts. R p c t i it would seem that more o b jec tio n s w d refusals to go further obtained from the larger firms. This is most ^ ` frequency of visits by the Health authorities, and also to mo.e u n i o n activity. ' ' t r T re tightening up their procedures concerning asbestos, laboratory p e S o ^ e l ^ e been instructed to wear masks wnen de the material. * . dealing with asbestos. The techrJ-cal p ew n n ha e s no substitute for the fibrous material, and they envisage w u w .will have to be made. 2.fc Dockers Until the last few months, asbestos was bass. Probably as a result of the television pro*.a=ne. the I* packed in indestructible containers. This . i . * e has no sp WT~S' r0r example, less than three weeks ago, a d.spu.e aros docks over a cargo of ach.stas asbestos., 500 yuu men. .were Involved, ar.d ev< tocethi" w employers had offered to supply * * < w m tf.e osterl,!. They ere Bristol. Hull Kid ( t o r c h e s ^ 3.0 ACTION TA>ZN =Y UNION CARBIDE 3.1 Visits V . ____. . . u. j 1 -7 - 0768*! J.l.l. Chemical Inspector of Health, Baynards House, 1-13 Chepstow Flace, Westboume Grove, London. Contacts Mr. R. Walpole. This is the headquarters and reference centre for the regional factory inspectors. The outcome of the meeting was a confirmation that the 5,000,000 particles per cubic foot threshold limit is ' currently adhered to in Great Britain. It is expressed over here a 176 particles per c.c. 3.1.2. Asbestosis Research Council, P.O. Box No. *0, Rochdale, Lancashire. Contact: Dr. S. Holmes. TCiis is a body set up by the three biggest asbestos companies i n Great Britain. It is primarily concerned with minimizing th asbestos dust atmospheres in their factories. TCieir ambitions . seem to have been almost fulfilled. Turners of Rochdale claim to have had only 3 deaths attributed to asbestos since l88l. They believe that these were the result of the last war when their operators were working long hours under- blackout conditions, add when a quantity of Crocidolite was used. This material had not been used before the war, nor has it bean used since. , ... U r. Holmes mentioned an item of great interest. Apparently, some types of masks used to protect workers from asbestos and other dusts, do themselves contain"Crocidolite as the filter medium. Turners have experimented with them, and have found that it is possible to inhale an extremely high concentration of asbestos in a short space of time. 3.1.3. Pneumoconiosis Research Unit, Llandough Hospital, Penarth, Glamorgan. Contacts: Dr. V. Timbrell,- Dr. A. Walters. ' This unit is a branch of the Medical Research Council. It was ' originated initially to study the effects of coal dust in the lung. . It is also associated with the U.I.C.C. (Union Internationale Contre . Cancer). . ' _ ... . . ... .. . . The group consists of about 12 dompetent men, among idiom Drs. Gilson* Wagner and Timbrell are world authorities. They are currently attempting to seek a solution to the problem of the aetiology of mesothelioma, and also to discover whether only one type of asbestos - is responsible for the development of these tumours. 3*2 Dockers- . ` Three courses of action have so far been taken: 0*2.1. ..... Meeting with the Shipowners and Dock Labour Committee, Uniac^Carbide being represented by Messrs. Cheston, Sayers and Sly. The purpose was to acquaint the dockers with our pelletised product, and to learn what fora of packing was most acceptable to them. The outcome of this meeting has already been described in a report by Mr. P. R. Chesten on loth February, 1967. -8 - 076846 3.2.2. . eiv were present at the unloading of 50 tons Messrs. c5e,JJ.a2 ? J 1puri?y pellets from the s.s. Bolinas. A of Union Carbide h-gh ...j <rion and the subsequent ddeisfcfriicputlitoyneonfcotihme te"refdinpersuading tne S o S r . to word It he* already been reported' by Mr. Sly. 5.. r..iF , 0* * - " - o t r . r i r ^ u e f o i . r ^ ; . : - and King Ci-y* Negotia .ntainer 'transport. One shipping lines who ?***** f ^ ^ b l e rates which should particular company h a s t0 S n d o n docks at a viable-cost enable material t o be J " ^ 1 osrtItly acceptable to the dockers, " -,,k .t. at the more important articles n s s s r." - ` > k.Q TNgQBMATION ACCSUSD .. _otid with AsbeswOS ... ` -1 g : : : .r. -- into the lungs. They are: ' - -- _ 4.1;1. Asbestosis. *. A.1.2. Bronchial carcinoma. A.1.3. Mesothelioma of the pleura and peritoneum. * * -- ` Evidence is now growing incidence tf cancers of the gastro # fr0B ^ lur-, but there suggested that asbestos f " s m y ^ i g ^ swaUowed direCt (ingestion is also the possibility tha y th# sisration theory has been , fibres 1 the U , . r ^ Ogp :':?y 4.2 Asbestosis Toni .sposure to .sb.lco. du.-. 1. ^ 101^ ^ complaint, silicosis. TRe. _;L,..c..>a slow, insidious, low - f.rc-.icn of f ^ b l e s t , . . 7 ? `c o y o t e s In she r.Sl=n of grade, progressive fibrosis, thlev enins of the bronchiole is. bronchioles. I s causes . the lesion 1 not . w.ll ar.C the ^ ' "" / `" ' ^ e l o p s , however, the whole U B & become, obstructive. As.-.flbrosis d dloxlde interchange between the scarred, so that the oxyg . This causes an extra burden on the s r m r u a ' -- *" " . . .I - 9- 076847 the asbestos fibre. This is laid down in concentric rings. The Ferritin material is a normal body constituent, and the iron component is believed not to be derived from the iron present in asbestos. 4.2.2. ' Mortality Rates: Examination of the figures covering the two ' periods 1931-46 and 1957-6** reveals that there has been no striking change in the years of exposure or duration of illness d In the deaths from asbestosis. There has, however, been a marked . change in the average age at death - a rise of nearly 10 years men and 20 in women. (This increase has been attributed to a virtual elimination of tuberculosis in the U.X. in recent years.) In 1964, the average age at death was 57 years, but even so, subjects who had been under heavy exposure to asbestos were dying in their 30's and 40's. p l d . i m i t a t i o n of th. Chryaotlle probably du. to a aolublllty Sflot. Flgur. 1 aftowa th. reaulta of giving .qnal ' ' * Chrysotll. Croddollte, Amoalt. id flnjly pod.red lj.a to rata bylnhalation. aach point on th. graph la th. c a n of 8 rats. ' (equal numbers of male and female). -- The . importance of particle l-ncth lengta in in the develop,m.e,,n.t 1ofarfiimbarlosis - la still not solved. Wagner has shown what in several ani_ai species, fibrosis of the lungs is produced by fine particles o r JSry short fibres. It is believed that long fibres may still be more fibrogenic for a given mass than short ones.- .3 Bronchial Carcinoma . h 1 w..u 0f Disease: This is the same type of cancer as that iV.;.*<r t'.. ' & ? ! ! ? . . . , a d It 14 no aco.pd that a.b.oa alao predisposes to this condition. . 4 *5 2 Mortal4-y B ates: The proportion o f asbestosis death certificates. ^fiio^ord.a cas.s : ,, r u n > . , littl. doubt that th. ln=r..a. la a r.al on.. ' Evidence of this is shown below in Table 1: -- - 11 - period MALES Asbestosis all deaths Asbestosis with lung, cancer % with cancer of lung *1924-50 1931-40 ' 1941-50 1951-^0 1961-64 1924-64 13 66 92 .. 144 ll? 428 - 13 - 21 . 45 62 141 'n i l 19.7 22.8 31.3 54.7 32.9 ' Table 1 076549 FEMALES Asbestosis all deaths Asbestosis with lung cancer 7 - 82 5 45 5 40 11 26 7 200 28 % with cancer of lung NIL 6.1 11.1 27.5 26.9 14.0 4.4 Mesothelioma 4.4.1. Occurrence_of Diseasjt Mesothelioma is the most disturbing of the three"diseases~attributable to. asbestos for two reasons, rirstly, in contrast to bronchial carcinoma, it can occur in people with ' minimal fibrosis, i.e. only after a brief.exposure, which may be as little as three months. Some authorities`even believe that a single brief exposure might be sufficient. Secondly, there is a very long time lag between the original exposure end the clinical appearance of the cancer. Thirty years is estimated to be an average time. 4.4.2. Cause of Disease: The most up to date information on the likely agent responsible for this type of pleural neoplasm was presented in a press hand-out issued by Dr. Wagner in February of this year. Be wrote: "On current evidence from South Africa, Australia and Britain, . it would appear that Crocidolite is mainly implicated in the development of mesotheliomas. However, cases have occurred in the U.S. (16 in number between 1963 and 1965) Canada (6 in number,_19:2-19o4) and a few in Britain, in which people con cerned appear to have only been exposed to Chrysotile. t present in Scuth Africa a continuous search is being made to detect ny eases e*'-esa-^e1ial tumour coning from the Amosite and Chrysotile Lning areas:~so farT none has been discovered. This search has also een c a r d e d out in Czechoslovakia where only Russian Chzysot-le is in se: again. no diagnosis of msothlial tumours is reported. Dr. Gilson, s-s-a-- h Director of the M.R.C. Pneumoconiosis Research Unit, and hi a"colleague. Dr. Wagner, have both stated in a number of papers that reir major task at present is to "establish whether ,;h,, tos is responsible for the development of these 12 - 076630 *.4.3* Experimental Work: 'Wagr.er at the Pneumoconiosis Research Unit has * * shown " l^64)"tKat under animal experimental conditions, asbestos appears to be a powerful carcinogen. Twenty mg. of asbestos injected into the pleura of specific pathogen-free strains of rats " "has'produced'mesothelial*tumours in a high proportion of animals. This is so for Chrysotile, Amosite and Crocidolite, both natural and after extraction of its natural oil by a single solvent. The. investigation, a survival experiment,'is not yet complete, thus, it is not yet known whether there are significant differences in the number of tumours produced by different types of fibres. So far, Amosite has produced the least. Studies on the organic components of asbestos are being carried out by Harington of the Chester Eeatty Research Institute. No hydro carbons have been Isolated from Chrysotile, but Crocidolite, which was mined in an area of South Africa with a high incidence of meso thelioma, contained 3,4 benzopyrene in relatively high .amounts. Harington (196$) has also shown that during a storage period of 6 months, asbestos absorbs 70-85$ of the Jute oil present in Jute sacks. It is not yet clear whether these oils are of any biological or medical importance. . The suggestion has been made that asbestos carcinogenicity may be related to the metals or metal complexes contained in asbestos fibres; Chrysotile contains nickel (0.5%) *nd chromium (0.1$), while Amosite . has manganese (0.7$). Serum can elute small-amounts of nickel, chromium, magnesium and manganese from Chrysotile, iron and manganese from Crocidolite and Amosite. Wagner's animal experiments tend to fiv the significance of iron unlikely, as the proportion of this element in Chrysotile is only about one tenth of that of Crocidolite or Asiosite. k.5 Aerodvrff^g behaviour of Asbestos Fibres 4.5.1. . Ttfluer.ee of Fibre Dimensions; Dr. 7. Tinbrell of the Pneumoconiosis ,. feseah~Unit has bein'"engaged for the past few years in examining gj.e parameters of fibres which influence their respirability. ..v investigations have explained the observation which puzzled earlier workers in this field, namely, the presence o* ,,ibres of 100 microns or longer in the lungs of men or experimentally exposed animals. ____________ The explanation is that the Farticle-free falling speed is tr.e cost important parameter influencing its entry into the lung. s fall_r.g speed is predominantly determined by fibre diameter, and shows very little sensitivity to length, especially when the aspect ratio (length;diameter) is high. If, therefore, a fibre nas a sufficiently small diameter, the falling speed can be low enough .or .he .ibre to escape deposition by settlement and inertial precipi.a.ion mec.^n-sms in the upper part of the respiratory tract. Hence, deep Fene to the pulmonary air spaces is possible. This has been s *own -o occur if the fibre diameter is less than about 3-5 microns. - 13 * 076851 4 5.2. Influence of Aspect Ratio: It would seem that the Longer the ' fibre,"the'mo re probability there is of it being intercepted by the nasal hairs. However, examination of asbestos particle lengths in the lung has shown them to be of the same order of magnitude as the distances between the nasal hairs. The possibility thus arises that the fibres in airways, in which the airflow is laminar, may align themselves with the streamlines. Hence if the . fibres are fine enough, they can be expected to show a capacity for wending their way through fine airways. \ * " There is no direct evidence available on whether fibres do tend to ' align themselves with the air streamlines. Dr. Timbrell has assumed that the conditions in an aerosol spectrometer prevail in the lung . airway. Consequently, he has measured the orientations of fibres in the particle deposits in this instrument. Figure 2 shows histograms in which percentage of fibres is plotted against angle to airstream in the aerosol spectrometer for glass, Amosite and Crocidolite fibres ' with aspect ratios <5* A similar histogram for fibres with an aspect ratio >5 is plotted in Figure 3. . It is seen from Figure 2,when the aspect ratios a r e <5. there is`no preferred orientation for any of the four fibres. However, for fibres with aspect ratio>5 (see Figure 3) there is a definite tendency for * the fibres of M l four materials to align themselves with the direction of airflow. m ' Furthermore, it appears from Figure, 3 that there is a more marked tendency for alignment of the glass fibres-.than for the fibres of the three types of asbestos. It is suggested that this is due to the highly synaetrical .character of these synthetic fibres, whereas the asbestos fibres, although highly selected groups, exhibit slight asymmetry. .6 Standard Samples At the International Conference on the Biological Effects of Asbestos in Sovember 1964, one of the conclusions was as follows: . "There are large differences both in morbidity and mortality of . asbestos in the surveys in different parts of the-world. These -- discrepancies may be explained by the different chemical nature of `the minerals, but there is at the sane time an urgent .need to standardise radiological findings and histology." . ' TV. . - The U.I.C.Q. working party on asbestos and cancer also realised this problem, and suggested that international samples.of the four main commercial types of asbestos be made available. Dr. Timbrell supervised the production of such samples in Johannesburg at the end of July, 1956. The five samples produced were: Amosite (SrAfrica). Crocidolite (S.Africa), Chrysotile (Rhodesia), Chrysotile (Canada) and Anthophyliite (Finland). The Canadian fibre consists of components from eight mines, and the most difficult problem experienced- was nixing them so that any portion of the standard sample as small.as a match head would be representative. 076852 Picure 2: Frequency histograms In which percentage of fibres Is plotted 2 S t 5 ? to the airstream (axis of duct) In the aerosol spectrometer, or S L i% o s iti? chrysotile and crocidolite fibres with aspect ratios < 5 IOO-I 0. Ill O a Z tti g 0ui. j 20 J ' 7 G | A :c h ;cw 0---- --- 0 = 30 ! ri jc 4 CH CR . [ 7 J--- i-- A ICHCR 30 -to *o-o ANGLE TO AIR STREAM v-i &&&$& Figure 3: Frequency histograms in which J" ?nJ"8Jh gfaeiosol spectrometer. against angle to the airstream " I S * tspiet ratios >5. for glass, amosite. chrysotile and crocidolite fibres witn p - 15 - 076553 The prepared asbestos has been packaged Into small, samples, which are now available for distribution. Studies of a wide range of physical and chemical properties of the samples are being made at a number of world research centres. ' 5.O EZQUZST FOR ANALYTICAL ASSISTANCE It is understood that all the major asbestos producers in the U.K. have proffered their assistance in conducting research work on the International Samples. Dr. Timbrell asked Union Carbide U.K. whether the Corporation would be prepared to assist in a similar manner. He requested that we should carry out trace analyses of the five samples. Apparently they have no adequate facilities at Llandough Hospital for doing this. Dr. Timbrell has also requested that we should examine identical aliquots of the Canadian Chrysotile sample to detemine whether uniform mixing was achieved in Johannesburg. ' It was explained to Dr. Timbrell that it was impossible to give an immediate answer to his requests. He was, however, promised a reply at the conference on . the physics and chemistry of asbestos minerals to be held in Oxford on July 19th. Dr. Timbrell, and, hopefully, Drs. Gilson and Wagner, are scheduled to be at his symposium, and arrangements have already been made for them to meet Dr. T. J. Hall and Mr. F. Mumpton of the Union Carbide Corporation. ` - 6.0 DISCUSSION 6.1 Moral 'Issues 6.1.1. There seems little doubt that the toxic effects of our Coalings product are still largely unknown. There is a general inference that Crocidollte is more liable to produce mesothelioma. Exoneration of Chrysotile has not been made, however. A discussion with Dr. W. Taylor of the Department of Social Medicine, Queens College, Dundee, two days ago, revealed that concern ever asbestosls is still increasing, and that Chrysotile is definitely implicated along with the other types of ^ asbestos. AV*': *'#4.''. It therefore seems that on the basis' of present evidence, we are not v: entitled under any circumstances to state that our material is not ' a health hazard. What is core, if it is believed that a potential customer would use our material 'dangerously', and that he is unaware of. the toxicity question, then it must surely be our duty to caution his end point cut means whereby he can hold the asbestos air float concentration, to a minimus'. 6.1.2. There has been general recognition that Union Carbide has shown a* praiseworthy responsibility in offering a pelletised product. Undoubtedly, this has contributed considerably to the continuance of negotiations with a number of papermaking firms, where dust extraction equipment to deal with an open product is inadequate. On the other hand, the Resin Grad topen) and High Purity open materials do not possess this benefit, and the moral question is 076854 brought to the fore because sales of both are foreseen In the near future. Carbide's responsibilities are somewhat lessened, however, as the customers will mostly be fines already experienced in the use of asbestos, and those who are always under the watchful eye of the Factory Inspector. 6.2 Expected Rise in Asbestos Diseases _ In Figure 4, a diagram has been presented relating the history of the development of the asbestos industry and associated health hazards. It .. ".is. seen that, the world production has increased tremendously since the war. With the knowledge that msothlial tumours can take up to 40 years . to develop, it is expected that there will be a dramatic rise in the next two decades in the number of cases discovered. If this hypothesis is proved correct, then it is certain that asbestos will receive Increasingly more adverse publicity. As a result, sales resistance to our product may be expected to strengthen. It is therefore imperative that we keep abreast of current research work and publications, in order that we may combat both informed and exaggerated criticisms. . . * 6.3 Threshold Limit Value It is understood that the maximum dust level of 5 Billion particles per cubic foot (still adhered to by the U.K. Factory Inspectorate) was proposed by an engineer in 1938 as an interim guide. - This figure was an arbitrary choice, and had no experimental foundation. - Dr. Taylor in his report of the International' Conference on the Biological Effects of Asbestos, 1964, says; "The M.A.C. (Maximum Allowable Concentration) of 5 million particles per cubic foot is not now acceptable. Industry should aim at 1 million particles, and accept this figure with reservations until .oricoowledge in this field is extended." Dr. Taylor reiterated this again two days ago, but he did admit that practically 2 million particles per cubic foot might have to suffice for quite a while to come. . : It thus appears that the sentence in Dr. Demehl's Asbestos Toxicology Reports . "It is now generally accepted that a man can work a 40-hour week for a lifetime without developing asbestosis, if the asbestos dust particle count-1*-kept- at or below 5 million particles per cubic foot of air.'' , . ' is now no longer held, to be true by a number of ir.forr.ed people. An indication of the present opinion on this matter held by Union Carbide s Tox-cology department would be cost welcome. _ 5.4 Similarities Between Different Chrvsotlles, At the moment, there are signs that Chrysotile may be le" " s p o w i b l e than Crocidolite for the development of mesothelial tumours. Shoul * either on statistical grounds or histochemically. th at^ tM sv i n d i c a t i o n ^ 17 PERSPECTIVES WORLDPRODUCTION development of the asbestos Figure ft O U g r a m rel.tlns the history of the Industry and associated health hazards. * 10 07B556 . .. . mtv, 0 f chrysotile which has been vindicated. The case could **<r?m S iS 1\w i5 Z p ii. of *>two s'*r-<urd Ch^ys0' u s"spl" ( c l S d l s n end S.African) la giv.n a total d . a r a n e . . 6.5 Fibre Aerodynamics - . O M Qf obvious differences between Chrysotile from the Coalings deposit ind that'from othor source, la Its lnharently mall " b" 'iJ ^ " " t S S a S r S t h e r with the unique wet refining method employed, has meant t..at tne.e vtry_small U n r a t e d flhro. .liable for inhaiatlon Into the lung. The diameter of a single Coalings fibre is less than 300 A0 . It has a^ e a d y b e e n shown In 4.5.1. that fibres stand a good c h a n ^ " 'w i t h T d i a m capable^of reaching the innermost portion, of pply to the fibre bundles contained in a bag the of open n a t e r l a * l a2s T. we 5 It nay be aeen from electron photomicrographs of Coalings " bestoa thad t h . fap" ? t l o is u s u a l l y m u c h greater th a n 5. * " ^ . ' i s 5T. tor factisprobablynot E TS S . th .'S w . will 5 ** ^ S i r s , and so will be capable of passing into the^d e p t h s of the -- 7.0 ireCQMMNDATIO?!S 7 .1 Oust Counts 7.1.1. Saesj. Dr. D e m e h l in the Toxicology R e port states: ~ * -in paper manufacturing, it would be d t i l n U i to know the *. .4. ' dust concentrations where the asbestos is dumped from bags into the pulp slurry." . . . ' Br. T aylor state, recently that he belie.. hare 1I h ^ i f S t h " * " *'1 m ooeni-- a oacer or plastic bag of asbestos than there is witn a e o n r . d ~ a l S s d a T s i c h . He was questioned on his reason for this, but r.o satisfactory_ar.swer was forthcoming. r- 'au.--or has himself witnessed A dust cloud in the vicir.tr/of :V sa " t` al r e t i S ed and open materials w h e n making u p customer . i d . `b s . H e ; S r h . A U r g e number of suspended particles were . visible in a torch beam. --_ _ . iSn^Ts" . . .w -t * dust count be made i n the region of a freshly ? ! ^ . ; t S V A Products The resdings cbtsined will be independent of the site of opening. 7 , , ____ _ ar/4 o-pirz Doctor: It is appreciated that dust conditions 7*1***' - - < 7i--- j'm-irh r .n tin as to the amount of a -- os- - 19 - r . * 0-7 ' , . << he very useful The asbestos concentration i* T r u Z 1irT " " ` ' " r t l G ? 0f this. Dr. Taylor has suggested " ^ 5 \ 5 S \ 5 - for a Period of. say. 8 hours. 7.2 analytical Assistance * s ^ s ^ irS s S fS s S S iL ^ s s i t ^ s i a f f o r three reasons: " a s s s is s % - Wagner and Tlcbrell are lea n Academy of Sciences Symposium or noticeable too that at the New yo a c * y ^ l f the the Biological Effects of Asbestos held last Autumn, a o o .contributions were from the .K. . 4n t * w s t in our material, mainly because 7.2.2 Dr. Timbrell has b r e structure. Ee as ttatec of the symmetry and uniformity of the experiaents with it. ilorh^lf th. Co.lir.ga caterial, at alongside th. S t a n d i . c l . research would make a good selli 7.2.3. The fact that we would b* "assi* "^ .*, tbe company has recog- point. It is f . U that if oustomers s.. ..nr. ' hised a problem, has tried to - elioeot refus, to buy solely assistance towards a solution, then tney canaov * on toxicological grounds. ICS :1k Asr.r.srps Tr-ATcr-T.rr.v r,;?cnT i It has been known for many years that soase persons working in asbestos production were prone to develop a disabling lung disease. In tice, this condition beeacs known as asbestosis and was related to exposure to hih concentrations of asbestos dust. With further experience, it was found that cen could work with asbestos without development of lung disease if dust concentrations were kept below a certain level. It is now gen* erally accepted that a ran can work a AO-hour week for a lit*atime without developing asbestosis if the asbestos dust particle count is kept at or belcv 5 million particles per cubic foot oz air. This dust concentration of 5 cillion particles per cubic cot of air is the Threshold Licit Value for asbestos, and no cases of asbestosis arc known to have occurred when exposures have been maintained at or belcv this level, despite large-scale utilisation (now approaching one million tons per year in the U.S.A.). CThis concentration of dust is generally not visible in the average vork"^) area unless a beam of light causing a _Tyr.dall effect is present. Usually the dust concentration cust be from.5-10 million particles per cubic foot be/or < r*t*n**e -- islble in avtTSilt: llr.ntir.g oonditiwtis. (everal years aso it was reported that there was an increase in the incidence oz cancerous tumors, especially of the lung, associated with asbestosis. ' Feeently there have been reports of some eancers occurring in individuals exposed to asbestos dust, but who have not developed clinical asbestosis. It is believed by most authorities that these cases have been associated with exposures significantly exceeding Che Threshold Limit Value. A major manufacturer of asbestos products who also mines asbestos has not been able to show an increase in cancerous growths in man working where dust concentrations were maintained at the Threshold Limit Value. ^Control of asbestos dust exposure is therefore necessary. T h e ^ - control methods are the struwj.-irri.omca applicabfc~ to a variety of ..dusty, operations. They inslude (Qoscd flew sysccmsJftfCC~procc3scs where possible^ and adequate exhaust ventilation wnerc openings"in the sys^gti are ~~r* necessary"! Pelletisin'*, is sometimes used to improve the (handling) character- Istlcs'of otherwise custy materials. Where satisfactory containment to 3Cay within the Threshold Limit Value is impractical cr impossible.(.efficient ana reliable respirators are_ availably:or the protection of the employes. A program of environmental monitoring is highly desiraoic to determine chat Threshold Limit Values arc not being exceeded. In paper ennutaccuring, it would be desirable to know the cust concentrations where the asbestos is .-y , t - been established as satisfactory, the rrcqucticy may be extended to occasional tests to assure continuation of a satisfactory condition. J L R / / e c x .45 - a to * -2- You should have this statement available or any questions vhich sight arise from your customers. If appropriate in your judgment, perhaps it should be discussed with certain customers who have not yet raised the subject. I do not feel we should make a big issue os it thereby drawing unnecessary attention to the subject since the conclusions Are still questionable. If you have any questions, please discuss them with me. Very truly yours, T.J.Hall/dk enc. v i W - . ^ Confidential 1 Report 29-55 MELLON INSTITUTE Special Report Jhe Fibroccnic Potential of a R 7-8-66 /^/ ' 12 pages -U_i_ 0E nPi0..EcXa .1i..j/! W R B Y iA_._K__E_N__N_E_DY COWTREPORTEH via ,Intraperitoneal Injection In Cuinos P i , ,Cs and R a h M ,, nd bv the Intratracheal Pu te n f h , Chemicals Division. Union Carbide Corporation Summary -Industrial Fellowship 276-29 products studied produced fibrScic lesions I f t i l ^ 1?dlcatr thit th sh t o s guinea pigs regardless or fiber r8ans ln rats * fiber), produces the most severe reLtion f J T l M r? % Pr! ^ S * aiS" 100 <refined (Johns M a n v i U e screened fiber) oreduce! * ? (standard fiber) and JM-3K results on rabbits ware * toilar but 1*" ' - * r.yctlonj. The ,,",, t ; ^ r ^ 5 ,^ ,s r i r 2 i i 8 lMi on?-in * i*.- cfae rata which received JM-3K fibars'. re' ^o laalons wert found in intratracheal rata, but only two r * ,, . Samnles k. L S n i " ** ' ^ * ' 2fc W 1/ So&rr CTS-100 Fiber (same as JT-100 Fiber) Standard Fiber" containing impuri ties in the form of clay and magne tite. a short fiber. Sterling Forest (Juantitv 8 oa. *CMS-ioo Tiber "Refined Tiber" with cesser impurities than JT-100. A Sterling Forest short fiber. .. 8 02. request of . K. I.' V Date Sample Received. Number 8-16-63 26-220 8-16-63- 26-219 yl f T - * but l i T V T o n T T s s;rt had .lc"6ths of -9 1 0 10 *>. ' 0,5 "ieron. The diameters oY the fibernu*an<1'*SOnie thC Were less than 1 ^ 4 5 - *,,"* --bu..c......t..h...u..f.- ere .smaller si. res noted".* Ti hnee Ce ?3?v-8n*n"f6r"r>'1?7rm *3 t0 1i _,2___B_i__c,,rons< Designacin of**3bestos Produce JM-3K Fiber. "Long Fiber"(brushed through screen to reduce fiber lung eh Co 1 nun. or less before injecting.) Source Manville, N.J. Report 25-25 Page 2 Quan-Rl-PF 8 or. Date Received 8-26-63 M. I. Sample Number 26-227 Methods Intraperitoneal Inactions fiber l e n g ^ t f ^low Tllrl and JT-100 asbestos samples v e r i pared as a 2.52 (K/V) suspension suspensions were sterilized J ^ * creen t0 reduce ics u s e d ^ rec2iv*d r w dSing* ^ C M S - 1 0 0 in 0 852 saline * Ai?Ch *5jestos Product was pre ! * . "** A11 needl" . syringes and .bdoM ,,. t a b l ,, Results ' . CMS-100 produced the most severe reaction in the s a - J i ^ - = .w .t w - ,,- . S 3. #i -vTheJJM'3K asbest0* fibers produced granulomas with fibers visil'i. 7 * '' ^ ^ r s r = 2 S L " o? - " - Methods Intratracheal Injection One per cent (W/V) suspensions of JT-100. CMS-100 JM-3K and a 0.52 injections f CMS' 100 Were PrePared in 0.852 saline as for the intraperitoneal Report 29-55 Rce 3 Female albino rats weighing in excess of 200 grams were given 1 1 f the respective asbestos suspensions by intratracheal injection. The rats war* anesthetized with saturated vapor of anhydrous diethyl-ether. The trachea was exposed by blunt dissection and the injection was made directly.and the incision closed with a Michael Wound Clamp. 7 * lncislon . \ rats wcre lnJccted with 1 ml. of a 12 JT-100 suspension (10 me asbestos). Eight rats were injected with 1 ml. of a 12 JM-3K suspension (10 * ' mg. asbestos). Because of the flocculent properties of CMS-100, only three rats Results " concro1- t *m m 2,*9` *hro-'h - -- ** - Specific icsions were found in most of the rats given CMS-100 and JT-100 that consisted of marked granuloma formation with bluish foreign body material Marked bronchioUrl, obllteran. v., S i T m i m i alee lT ly ln* eer1* 1 "ithln eh. lesions. The JT-100 rats had a ore severe were a ra ts fibrotic reaction to this foreign material. Multinueleate giant cells common feature with the granulomas of the JT-100 Si^wf conspicu ously absent in the lungs of the rats.given CMS-100. Micropathology was performed r * s s r TM o T ^ . si o r K B*uh" - & (? lL j Edwin R. Kinkead, B.S. Research Associate ( 3*7./, ^ a , Urbane C. Pozzani, M `S. > ( Y Senior Fellow ' Approved: Acknowledgments; Technical Assistance Pathological Examination Data in Book 868, pp. 63 to 90 and 99-109. Typed: July 11, 1966 - aid >--"y'V71 T \ { r7 j Jr. < < Charles P. CarpenteryS?h.D. Assistant Administrative Fellow Charles C. Haun, B.S., Junior Fellow John M. King, Ph.D., DVM, Fellow Dose of Asbestos Animal Number Intraperitoneal Infections of Asbestos C H S - 1 0 0 Days to Death or Sacrifice . Gross Pathology Hlcropathologv 50 mg. ( 2 ml. of 2.5Z suspension) ' . P. 96813 20 D P. 96603 75 D P. 96615 P. 96806 P. 96602 240 D 270 D 286 S P. 96607 286 S P. 96610 286 S P. 96811 286 S P. 96812 286 S P. 96814 P. 96821 286 S , 286 S Peritonitis! asbestos scattered throughout abdominal cavity. Peritonitis; adhesions of intestines to liver. . Autolyzed. . No asbestos in abdominal cavity. * Multiple small adhesions of the omentum to the mesentery. Adhesions of liver to stomach. Deposits scattered in the intestinal mesentery. Omentumal adhesions to liver with deposits in the omentum. Intestinal adhesions to midline and seminal vessels. Areas of fibrosis in most of left liver *lobes. Adhesions-- liver to stomach and intestines. Adhesions of abdominal wall to liver, stomach and omentum with deposits. Not examined. Not examined. Not examined. Not examined. Several small, well marked i>,rsr.u- lomas with giant cells on the serosal surface of colon. Liver-- 'marked granulomatous re action on the surface. Granulomas-- serosal wall. Liver-- well marked granuloma?. Marked chronic granulomas <'5 the intestine and diaphragm. Intestinal, liver, skeletal muscle-- adhesions to each other Areas of giant cell formation. Colon-- large cystic masses filled with debris. Lined by columnar epithelium. . Liver-- fibrosis and granuloma formation. Foreign body granu lomas on abdominal wall. Granulomatous lesions of the Stomach, liver and skeletal muscle._______________________ II. 96737 II. 96574 60 D *270 S Numerous deposits of asbestos adherred. to intestines. ' < Multiple adhesions, ventVal colon and urinary bladder. Not examined. Multiple well encapsulated granu lomas present with lnnumcr.'hle giant cells. '.TV' ' (Continued) a a ft n* in u it o i> ft *N s of Asbestos Animal K'unber "B* i ml. of 2 .5 " tension) R. 4571 R. 4678 R. 4629 R. 4631 R. 4634 R. 4660 T able 2> -9- (Continued) Days to Death or Sacrifice Cross Pathology 20 D 170 D 258 S 258 S 258 S 258 S Congested lungs and liver; asbestos scattered throughout abdominal cavity. Asbestos deposits throughout abdominal area. Nodules of white material in mesentery, ventral and abdominal wall. Deposits in the mesentery and ligaments of the testicle. Chronic abscess pneumonia. Scattered deposits in mesentery and wall of small intestines. Adhesion of testes to intestines. - Micrcnatliology Not examined. Kot examined. 7 Scattered granulomas in intestine and skeletal muscle. Multiple granulomas with giant cells and asbestos deposits. Chronic bronchopneumonia. Large granulomas, well encapsulated Report 29-55 Rage 5 .1 Intraperitoneal Injection of Asbestos JT-100 ose of Asbestos t 0 mg. 2 ml. of 2 .SZ uspension) Animal Number P. 96844 P. 96851 ' i P. 96849 P. 96834 P. 56835 P. 96837 P. 96839 P. 96840 P. 96841 . P. 96847 P. 96848 Dayf to Death or Sacrifice ' Cross Pathologv 11 D 150 D 185 D 286 S Peritonitis, asbestos scattered throughout abdominal cavity. Entire gut adherred together, i.ivcr ad herred to ventral wall and diaphragm. Multiple visceral adhesions of the asbestos tp the ventral abdominal wall. Cray deposits in the ventral abdominal wall. 286 S 286 S 286 S 286 S 286 S 286 S Severe multiple adhesions with pus in corporated. Multiple intestinal adhesions. Gray deposits in the abdominal wall. Omental adhesions to the liver with tiny deposits in this mesentery. Spleen adherred to ventral wall, stomach to diaphragm. Multiple tiny deposits on left liver lobes and left abdominal wall. Omental adhesions to the ventral tips of the liver. ' . 286 S Deposits on the intestinal mesentery and abdominal wall with omental adhesions. Hicronatholocv Not examined. . Not examined. Not examined. `I Scattered foreign body granulomas with slightly elongated fibers . of asbestos in them. Typical granulomas. Adherred masses with many granu lomas on the serosal surface. . Typical connective tissue granu lomas . Typical connective tissue granu lomas. * Numerous granulomas with foreign bodies present in them. Typical granulomas with foreign bodies, giant cells, fibrosis present. Typical connective tissue granu las. ` II. 96729 270 S Heart covered by chronic connective tissue. Essentially normal. II. 96734 270 S Multiple serosal deposits scattered pri Essentially normal. marily on the colon and ventral wall. (Continued) v w n n 00 tl < o I o% rt K1 AO I l/l Tabla .1 (Continued) ose of Asbestos Animal Number * 5 mg. One ml. of 2 . 5 X uspcnslon) R. 4576 R. 4536 R. ` 14534 R. 4617 R. 4596 Days to Death or Secrifice 36 D 160 D 200 D 242 D 258 S Cross Pthlbnv a Cannibalized.^ Autolyzed. Peritonitis, pleuritis, some fibrosis in pl&ural cavity. - Pneumonia. Asbestos particles scattered throughout entire abdominel cavity. Slight deposits in the mesentery and omentum. Micronatholonv Not examined. Not examined. Not examined. 9 Not examined. Intestine-- typical granulomas With foreign bodies. < :/ Report 29-55 Page 7 \ T abi* 2*95 Intraperitoneal Injections of Saline Coirtrrol * ose of Saline Animal Number p. p. * p. p. p. p. 96857 96856 96853 96658 96852 96659 p. 96860 p. 96861 p. 96862 p. 96863 p. 96864 Days to Death or .. Sacrifice Cross Pathology 88 D 156 D 170 D 207 D 286 S 286 S Pneumonia* Pneumonia* Pneumonia. Pneumonia* Essentially Essentially normal. normal. 286 S 286 S 286 S 286 S 286 S Emaciated. Liver massively reduced In sice. ' Essentially normal. Essentially normal. Chronic nephritis in both kidneys. Essentially normal. . R. 4484 R. 4483 R. 4531 R. 4540 R. 4542 R. 4557 12 D 258 S 258 S 258 S 258 S 258 S Pneumonia. Chronic abscessed pneumonia. Essentially normal. Essentially normal. ' Essentially normal. Essentially normal. MMM Hicrooathology Not examined. Not examined. Not examined. '9 Not examined. Essentially normal. Scattered areas of interstitial pneumonia. Liver necrosed end ahstcsscd Essentially normal. Essentially norr.ai Chronic interstitu'. Essentially normal. ..... ,.rti 1 .. Not examined. Massive abscessed pneumonia. Essentially normal. Essentially normal. Essentially normal. Essentially normal. % 'Mf .V: y-4>: Report 29-5 Page 9 kn Intratracheal Infections of Asbesto CHS-100 to Rata Dose of Asbestos Rat Number 1 0 mg. (One ml. of 11 suspension) 84636 84645 84702 5 mg. * (One ml. of 0.51 suspension) 72531 81427 81433 81440 72528 77679 77680 81600 Days to Death or Sacrifice 30 S Pneumonia. 90 S Pneumonia. Dross Pathology 180 S Chronic pneumonia. 12 D Cannibalized. 30 S Lung-- appeared normal. ' 90 S No lesions. 90 S Chronic pneumonia. 180 S ` Not recorded. 180 S Lipid foci in lungs. 180 S 180**S Cray foci in lungs. ` Pneumonia. . % ftlcrooAthoioev Pneumonia numerous granulomas . scattered throughbut lung. Pneumonia lesions of bronchloliti obliterans In several bronchi * and bronchioles. Scattered granulomas; lesions of bronchiolitis obliterans with foreign material and thromhoiic- like areas. Not examined. Multiple granulomas; bluish ma terial present in all granti- . lomas. Scattered small granulomas. Some bronchiolitis obliterans also apparent. Pneumonia; scattered granulomas; bronchiolitis obliterans. Scattered small granulomas. Bronchiolitis obliterans. Chronic granulomas Sans giant cells. Numerous scattered granulomas. Multiple granulomas scattered * throughout lung. Bronchiolitis obliterans. >sc of Asbestos 1 mg. ine ml. of 1Z .sponsion) Rat Number 84629 84672 84669 84633 846S9 84674 ` ' 84676 84631 > Tabh Intratracheal Injections of Asbestos JT-100 to Rata "'y, ' MlHl Days to Death or Sacrifica a Cross Pathology 60 D 123 D 151 D 30 S Large white areas on lung; atelectasis of the right lung. Pneumonia. . Pasturella pneumonia. * Chronic pneumonia. 30 S Chronic pneumonia. 90 S 90 S 180 S Pneumonia. Chronic abscessed pneumonia. Not recorded. Micrcsatholoev . Bronchiectasis. Areas of acute bronchopneumonia. Not examined. Not examined. Multiple granuloses and bronchi olitis obliterans. Pneumonia; granulosas, large lesions of bronchiolitis ' obliterans. Numerous granulomas, well marked bronchiolitis obliterans. Scattered granulosas. . Cranulomas, some bronchiolitis obliterans. se of Asbestos mg. ne ml. of 1Z spension) 1 Rat Number 84695 84635 81214 81171 81161 84660 Table 29-98 Intratracheal Injections of Asbestos JH-3K to Rata Days to Death or Sacrifice . Cross Patholocv Mlcropatholocv 10 D Entire lung was dark red. 13 D Chronic pneumonia. . * IS D Pneumonia and emphysema. % . 50 D Chronic pneumonia; bronchial lymph nodes, enlarged and gray. 30 S * ; Chronic pneumonia. 180 8 V Chronic pneumonia and enlarged lymph > - , nodes. * 0 Not examined. Not examined. Not examined. Not examined. Chronic bronchopneumonia. Chronic bronchopneumonia, a few scattered granulomas. MJ J H M 19 ose of Saline ne m l . Rat Number 78253 78273 78302 78717 84639 84646 8^651 84677 Table 29-99 Intratracheal Injections of Saline to Wats Days to Death or . Sacrifice Cross Pathology 30 S 30 S 90 S 90 s : 180 S 180 S 180 S 180 S Essentially normal. Essentially normal^ Essentially normal. Azygous bscessed. Essentially normal. Essentially normal. Essentially normal. Essentially normal. Micropatholoev Essentially normal. Essentially normal. Essentially normal. Few areas of chronic Essentially normal. Essentially normal. Essentially normal. Essentially normal. 1 pneumonia. ' Page 12 M tO IIn ui MAILING LIST Medical Departments A - C. U. Dernehl 1 - E. Q. Hull 1 - R. E. Joyner 1 - R. J. Sexton 1 - F. E. Medford 2 - R & D Departaent Library S. Charleston, W. Va. 10 - P. McDaniel 1 - N. H. Ketchaa 7 u 1 w Material Safety Data September 1, 1972 ' UNION CARBIDE CORPORATION 4625 ROYAL AVENUE NIAGARA FALLS, NEW YORK 1<302 TELEMONE: (714)349-3311EXT. 47 KIRBY A. KENNEDY BOILING POINT AND MELTING POINT: Not Pertinent SPECIFIC GRAVITY (HaO1l: 2.45_________________ _________ ________________________ VOLATILE CONTENT: Absorbed Weter 1- 4%By Weight 'Structural Water Approximately 13%by Weight APPEARANCE: Pellets or Fine White Powder. No odor. Very Slight Solubility in Weter. lliHAZAROSINGRDIENTSr Not Applicable. I m Material is not Combustible. No Fire or Explosion Haxard. l\te R B t C T I V l T y ? D A T A } : INERT MATERIAL: No Decomposition or Polymerixation Conditions PERMISSIBLE EXPOSURE TO AIRBORNE CONCENTRATION: The current standard of the Occupational Safety and Health Act of 1970 contains the following exposure limits: , , "The 8-hour time-weighted average airborne concentration of asbestos fibers to which employees are exposed shall hot exceed 5 fibers per milliliter greater than 5 microns in length, as determined by the membrane filter method at 400450X magnification (4 millimeter objective) phase contrast illumination. No employee shall be exposed at any time to airborne concentrations of asbestos fibers in excess of 10 fibers per milliliter, longer than 5 microns." (Federal Register - Vol. 37, June 7,1972, page 11320). _____________ _______ _ EFFECTS OF OVER EXPOSURE: Prolonged over exposure may result in lung damage. EMERGENCY AND FIRST AID PROCEDURES: Not applicable. Material has nc V liS B lC REST STEPS TO BE TAKEN IF MATERIAL IS RELEASED OR SPILLED: spilled material by vacuum cleaner or by water wash. Avoid inhalation of dust. Remove ______ ___ ____________ . WASTE DISPOSAL METHOD: If reasonably foreseeable handling will not produce airborne concentrations in excess of (*"' ' no special procedures are required. When limits are likely to be exceeded, waste and scrap *h'" f and disposed of in impermeable sealed bags or other closed, impermeable containers, suits y Union Carb.de Corporation assumes no responsibility and makes no warranty, expressed or implied, repre sentation, promise, or statement as to completeness, accuracy, or currency of any data provided^ V* ?>*; 'p- [K 07347 -i 076912. , ^ NEW YORK^p - -r t s M und j * ^ ' T / x-- T-- ! - , ! V ___ J \ V / V J ! I I * SAN FRANCISCO \ I I ----------- \ V ! \ ) / \.J i J -A r KING CITY ------1.----------Tf.x---i----- \---- . n -- -r*" \ |^ \ \ . 'S i / ATLANTA ^ ' i ______ j \ ! \ ____ S..- \ U-, ' - t * yw u DEPP- ^ * H * kirbv a . COURT ripO R T W Northetitern R#0on 270 Park Avenue New York, N. Y. 10017 212 551-**20 Southern Region 1371 PmcMth S t N-1. Atlanta. 6a. 30309 40* 873-4966 Kuweit Region 1300 Lakelide Avenue Cleveland. Ohio 4*11* 216 621-4202 Weitern Region 22 Bettery Street S n Frend.co.Clit.9*106 415 9821360. Ext. 16 .8E?0 . w / L K I R B Y A. K J ' i N S O Y COURT HSi'ORTnH .*3r Morena oareiK uaiia 0 0 September I, 1S72 ' ' UNION CARBIDE CORPORATION . 462S ROYAL AVENUE . NIAGARA FALLE, NEW YORK . 142C2 TELEPHONE: (7161 288-3311 EXT. 67 \ ( D v U . O. PRODUCT: Chrysotile.Asbestos CHEMICAL FORMULA: Mg6{OH)gSi,O10 L i PHYSlCACT/VTTfer BOILING POINT AND MELTING POINT: Not Ptrtintnt SPECIFIC GRAVITY (HaO1): 2.45_________ VOLATILE CONTENT: AbsorbedWater 1- 4% By Weight 'Structural Water Approximately 13%by Weight. APPEARANCE: PlleB or Fin White Powder. No odor. Vtry Slight Solubility inWater^ HL HAZATtROUSINGREDIENTST Not Applicable llte F fR E Material i*not Combustible. No Fire or Explosion Hazard. INERT MATERIAL: No Decomposition or Polymerization Conditions, ZROE PERMISSIBLE EXPOSURE TO AIRBORNE CONCENTRATION: V o . -. st.cd.rd .1 <h. Occupaticnal S .fm end H.ilth Ac. of .070 .m ein.W . M ~ < " f " " n ^ U o o r ,,m w w.igh we-eg. si-bom. m enus,ion of M TM which oploym ere ccoowd 2 S libw, pw m..... . greater then 5 microTM io lengW. as determined 0 We membrane f r method at 400-450X magnification (4 millimeter objective) phase contrast illumination. No mP|v,e ** T b " i T w o .n . conc.ntre.ions of s.be.to, fiber, in ^ of 10 ben p o r. long.- than 5 microns." (Federal Register - Vol. 37, June 7,1972, page 11320). V te SPILLOFPLEAKmPROCEDURESr I t pH o BETAKEN IF MATERIAL IS RELEASED OR SPILLED: spilled material by vacuum cleaner or by water wash. Avoid Inhalation of ctot. Remove WASTE DISPOSAL METHOD: . If reasonably foreseeable handling will not no special procedures are required. When limits are likely t0 * containers suitably labelled, and disposed of in impermeable sealed bags or other closed, impermeable containers, suitably l.be eo Union Carbide Corporation assumes no responsibility and make, no warranty expressed or implied, r.presensation, promise, or statement as to completeness, accuracy, or currency o any ata prov* . UNION CARBIDE HIGH-PURITY ASBESTOS A NEW WHITE FIBROUS FILLER A N D RETENTION AID FOR PRINTING PAPERS IT PROVIDES: IMPROVED SHEET FORMATION VR3CKJT ASES2O0 VBX AXB3ROS IMPROVED Ti02 RETENTION INCREASE DYE RETENTION NO A S B E S T O S - 7 " Ind - 2 2- J WIRE____ ______ / F E L T __________ 3% ASBESTOS " 7 - n a -1 " u. bJ IK WIRE // ------------------- f TRAVERSE OF SHEET Opocity Brightness Reduced Show-Through PLUS Cellulose Fines Retention & LLdEPO. e x h . 2 * L _ KIRBY A. KENNEDY count *e o ter Printability Improvements ... Reduced Static Electricity Buildup ^ * ____________ SEE ATTACHED MILL TRIAL DATA K1RBYA.KSMEDV COURTsWH le ft_____ RETENTION OF TITANIUM DIOXIDE IN BOND PAPER 076666 of Trial: Improve Titanium Dioxide Retention to b e t either material cost savings or improve the opacity o f 37 Bond produced by this paper company. Type o f Paper M achine: Open Fourdrinier - 126" Trim - machine speed 700 ft/m in . ' production rate: 7 0 tons per day. fm isb (in u se): 18% Hardwood-Sulfite 26% Softwood-Sulfite . 56% Softwood-Kraft ... A d d itives* 1.6% T a lc ------------------ 13.0% C la y -----------------0.4% Emulsified W ax... 3.0% Titanium Dioxide Furnish Change During Trial: > no change no change no change 2.4% A sbestos nochange to 10.6% Clay no change to 2.4% (P ost trial retention data indicated that 1% T i0 3 could have been removed without a loss in o p a c ity ). ' ` * Savings Resulting From Improved TiOi Retention: Reduction o f T i02 : 1% o f 70 tons o f paper per day = S 350/d ay savings. C ost o f 2.4% asbestos (3 4 /Ib . due to 2< /Ib. clay reduction) SiOO/day N et savings per day due to asbestos retention o f T iO j....----------------- * 2 5 0 o r S 3 .6 0 /to n paper Annual Savings ...... ____________$ 3 7 ,8 0 0 These savings are tor this one grade being produced 150 days P . .... Actuafly thu company has other grades where the sam e results may be obtained. Other Gains associated with this m ill evaluation: toreduced stream polutton and more tons of paper per 100 tons o f stock. 2 . Closure or more uniform formation was indicated by porosity readings. J . O padty n t a above. * * * . . < " f t o , .. - `` * 4 . Smoothness values were improved. ` ` Physical Characteristics o f the Bond Paper produced: Percentage Asbestos: Basis Weight (lb s./3 0 0 Ft*) ' Machine Direction Tensile Cross Direction Tensile M ullen Tear . Smoothness (G ain) Opacity (G ain) ' - Brightness Wax Pick ` Caliper . ' % Ash in the Bond Paper (gain) 0% 35X 1 2 .6 8 .3 2 0 .6 3 2 /3 3 53 8 2 .5 831 8 /1 6 3 .2 3 1 0 .2 1% TTJ5 1 3 .0 8 .0 2 0 .8 3 0 /3 3 32 .8 3 82-83 1 8 /1 8 3.09 ` 11.3 '' - 2.4% *30 13.8 6.5 2 2 .0 3 4 /3 6 1 31. 8 4 -8 4 .5 82 1 8 /1 8 3 .1 0 1 2 .4 a p p l ic a t io n RETENTION AIO IN PAPER Mitt SAVEAtt OPERATION 076667 OBJECT, REDUCE SOLIDS LOSSES AND REDUCE RIVER POLLUTION DRUM TYPE FILTER W ITH STAINLESS 6 0 /4 0 MESH W IRE USING FRESH t v p p O F SAVEALL: OLIVER CELLULOSE PULP AS A FILTER A ID . FROM EXCESS W HITE W ATER RETURNED FROM THE PAPER M ACHINE m a t e r ia l t o b e r e c l a im e d 1. Titanium D ioxide 2 . Clay 3. Cellulose fines 4 . Starch 5 . D ye particles Data for the operation: Production rate o f Paper M achine : 60 tons/day 800 fpm Wire m esh -- 75x58 T otal Filler Content: 6.25% (1.25% T i03; 2.5' Furnish: 50% Magnifite Hardwood 30% Softwood Draft-Spruce 20% Broke pH 5 .0 with Alum % A sbestos. F low Rate (G PH ) Average Solids is Ib s./1000 gals. Num ber o f days/year fo t this particular condition V alue of Material S /ton A N N U A L SAVINGS RESULTING FROM TH E USE O F ASBESTOS: S27.000 1,000,000 * APPLICATION-- RETENTION OF FILLERS Novel Paper No. 22 for Cotor Books QTooj typ e Paper Machine: Open-Fourdrinier Pxoduction Rate: 150 tons per day Systems pH: 4.5 - 5.0 g i f W eight: 32 Ib ./1000 ft* M achine Speed: 804 F .P.M . Furnish: Priortom* ofAibtrto* 80% Groundwood 20% Unbleached sulfite 5 % G eorgia clay 0.3% Tetrasodium Polyphosphate 0.4% Zinc Hydrosulfite 0.3% Alum 2.8% Zeriex 0% Asbestos with t % Aibwm . 80% 20% 5% 0.3% 0.4% 0.3% 0% 2.2% -- added Other additives to die headboa: Kymene 557 ---- 11..77%% .. Retention Results: % Asbestos % Clay % Total ash 0 24 . 30 % Increase due to asbestos, (d a y retention) . % Increase due to asbestos (total ash) J2& 39 43 62% 43 } 52.5% ave. Paper Tests with and without A sbestos: Basis W eight (Ib s./3000 ft.*) % Ash % Opacity Two-sidedness ' ' . 0 % AibnUM 32 4.4 9 2 .9 Ipt "E1conro.omn Iikci:GG-Laaiinn aanndd QQuuaaHlittyy Im ^ovcm ents: 1 reoll , 2 g% ^ .1 . X X TM . * or i t o / d y m . to %S% Aabcrto 32 (5 9 3 .6 0-O.Spts. ^ T u * - '- [mmediate cost advantage. W ith a rrSfSrtk^ rate 2 ft result was a total daily savings o f 5 6 8 0 /day. - * -- - * p < . 2 Reduced twtwidedness during the use o f High-Purity A sbestos also gave an improved paper product teU-r "*1 I /V INTERNAI- C O R R E S P O N D E N T a IOH C A R B I D E C H E M I C A L S C O M P A N Y in s t it u t e p l a n t f. o. 'i in\. tinFitsi:!i. v.,T vj.*: II Mr. C. J. Ratcliffe Industrial Relations A*u 20 July l?c2 O*0t. Medical Department - Plant 512 AmaiMf lillirtti .V r Mr. L. N. Dickinson Mr. C. H. Daniels Mr. H. S. Eastman Mr. R. A. Huber Mr. B. F. King Mr. F. B. Snyder Dr. C. U. Demehl Dr. E. M. Best Mr. E. C. Heinz Mr. P. E. Henry ^ Mr. R. A. Heal Mr. D. R. Matheny*^^ Mr. K. H. Ketcham Insulation Slock Dust Sur/ey ' Construction Insulation Snop Plant 511 Enclosed is as industrial hygiene report hy Mr. R. E. Peele on the potential hanardousness of "nev and improved" "Thermobestos" insulation blocks submitted hy the manufacturer for evaluation hy hand sav processing in the . _ . Construction-Department's Insulation Shop. The report points out that the three ow improved" sample blocks, subjected to test conditions identical with these in use and reported upon in March of this year, are an improvement somewhat, hut these blocks too, release quantities of asbestos dust particles into the working environment considerably above the acceptable aafe limits (i.e., the T.L.V.). Therefore, definitely,'the processing of "new and improved" blocks also constitute a hazard to health. ~ Mr. Peele reccsssends that Thermobestos" blocks not be processed in the Construction Department Insulation Shop until they meet acceptable standards and I concur fully. * - Very truly yours, RJS:gl Enclosure o R. Pc Sexton, M.D. . Plant Medical Director . `iiv > DEPO. EXH. - 2 V KIRBY A. KENNEDY COURT REPORTER internal c o r r e s p o n d e n c e ' r' JC. o n CARBIDE CHEMICALS COMPANY R. J. Sexten, M.D. Medicei Department --T N INSTITUT! PLANT t. 0. EM 23i. CHMiBTOM. V$K '- o. 3 Decerher 15^2 o , o . i . Industrial Hygiene - Pleat 512 AmwrtA| !*** M i*tf Toh-s Ksrnvill* "Thermstestes1 w idntifl,4 . 2i vp-- h 1562, an Industrial Eysieoe Report, i.e., 62-E-1-6-1, tu ateza-d to health in the Construction Insulation I " * ' ^ L ; L : ilock, htooftotorod ty jetos :ended r* S"' kel" 20 * " * (t) s i s r - S i S k concentrations in excess of 20 nppe- of air. 5 -s r*-* . * accordance Insulaticn Shop discontinued almost immediately tn p Insulation blocks. & ' - Co 20 July 1962, . = 4 tosiletlto ~ " m62a-tIeHr-i2a-lGs-s#up^pliJed^hSy^tjheS Jlo'hnSsS l l i e Company. This report concluded that Hovever> ^ u#t concentrations these caterials vere ' insulation blocks were substantially in excess ^ r 4 emnended^safeconcentretions'** 20 tppef of air. Therefore, the _ _ of t b e r e c a n c e n d e ^ s a r a j o n ^ ^ ^ o r t x e B a l n e ^ e x a c t i y _ .;.rr;;V-*^4 ;' . 0 * r * ? J S * L ^ T ^ S "S S * S ^ r Geosr.1 For* of the K. Oordeo, tod H. I. Xtoftoo, vere representatives, i,e.,. Messe.s. present end had requested a ltv th. pient Industrial Hygienist. This 2~ afvhich tlr-e Mr. Saxer produced meeting was held in the^lotcy report submitted by the Johns Kanville the acccmpanying copy o* porticos of O v i l l e , H.J. Hr. Saxer stated that, Industrial Eygiene Labrate^ lo^ d ` n0t~dle to produce results which eSreed in accordance with this r e p o r t , * ^ *hls department. Therefore, with those contained in the -epor ^ *helr methods of.reproducing they were concerned and Interested in learn-- g - * _ _ .. dHihs Johns Maavilie trade naie for thelf Insulaticn blocks I 2 D E P O . E X H . llff fel KIRBY A. KENNEDY C ' ' f*\ H. J. Sextos, K.D. 3 December 19^2 Page 2 our environmental conditions, sampling d evaluating the dust concentrations contained therein were subject to question. At this point he stated also that this conclusion' was promoted on the basis of their analysis of the etncspheric to s t conditions produced by their competitors product, (i.e., Xaylo or Iter =AT in the report) which in no way agreed with the deta submitted in the Industrial Hygiene Report **-]3-62-I-G-I. It was explained at this point, that this department's interest in this probles is always confined solely to the environmental conditions as they effect the health of our workers, and that no part of the investigation should be construed as an attempt to arbitrarily promote the use of one company's product over that of another. ` ~ Upon completion of this statement, Mr. Saxer proposed that it. S. R. Katheny and the Plant's Industrial Hygienist sake a trip to Kanville, New Jersey, at Johns Manvllle's expense and at a time selected by Union Carbide. This visit would be for the specific purpose of observing, scrutinising and comparing their setbod of atmospheric dust evaluation with that as utiliticed by the Institute Plant's Industrial Hugiene Department. It was Hr. Saxer's opinion that such a visit would permit a more positive approach to the probles and remove the possibility of misunderstandings, etc., that results ires written correspondence. At this point, Mr. Saxer was assured that there would be no personal objection on my part to the performance of such a service. However, .a proposal of this nature would have to be submitted to the Plant Manager, Mr. I. N. Dickinson, through appropriate channels before a final decision could be made. In conclusion, it should be stated that a phone call was received from Mr. F. S. Ccmerfcrd of Design and Construction on the morning of 21 November'1962, who requested that he be brought up to date on this specific problem. .This request was immediately satisified both by verbal explanation and by the promise that copies of both reports, i.e., 62-2E-I-G-I and 62-E-2-G-1, would be mailed to him immediately. Mr. Ccmerfcrd further stated that we should not back down on our requirements, but that it probably sight be vise to consider their proposal in light of the many ramifications of the probles as it affects the whole company structure, i.e., purchasing, sales, manufacturing, etc. Very truly 'toe. Robert E. Feele Industrial Hygienist R?:gh Enclosure i INTERNAL CORRESPONDENCE INSTITUTE PLANT r. o. aox :i CHiaUO:;, Vt'iSTVIC Mr. S. C. Ciesbruuo ** laiustrier Relations OlU ! December 162 e,H Meiicel Department Anw0ri*f {*(!#fid riant 512 *r Kr. L. K. Dickinson Hr E. C. Seins Mr. C. B. Daniels Mr P. E. Henry Mr. N. S. Eastman Mr. R. A. Huber Mr. R. A. Real Mr, D. ?.. Katheny*^1 Mr. S. F. King Mr, K. H. Ketchaa Mr. F. S. Snyder Dr. C. U. Deraehl 'Dr. E. M. Best, Jr. lasuieticn Slock Dust Survey Construction Insulation Shop Plant 511 ________ Two reports by Mr. R. E. Peele have been issued on th<s subject (21 March 1962 and 20 July 1962) end seat out under ny signature, to 16 May 1962, a copy of a letter froa Doctor Rale to the UCC Central Purchasing Department in Rev York perteining to this subject vas sent to soae of the people on the above distribution list. Undoubtedly, Johns Manville is extreicely interested in having our Construction Depertsent use their "Theraobestos" blocks. However, I believe that possibly unnecessary pressure, is.being applied to us froa several sources. The enclosed report by Mr.. Peele includes information cn an invitation for Mr. Peele to visit Manville, New Jersey, at Johns Manville's expense to evaluate their industrial hygiene studies. Mr. Peele points out in this report also that he has been contacted recently by the Design and Construction Department at the Technical Center who have implied that Mr. Peele should comply-with Johns Manville *s proposal. ' . ,, , , 'It is opinion that we should continue to do surveys, with limitations, on saaples of "theraobestos" blocks that are of a new formula and are submitted to our Construction Insulation Shop at the Institute Plant . W r evaluation. However, I an not in favor of Mr. Peele accepting Johns " 'i '' Manville s invitation and. would appreciate approval or disapproval for this trip from my supervision so that Mr. Peele can be informed accordingly. Very truly yours, ^ RJSrgh ' Enclosure . ' . Plant Medieal Directe? LL PEPO. KXH. ylf/*t KIRBY a .Ke n n e d y ... .1 ....... I 1 i IK T S R U A i. CO KRCC, O K SC N C i p; y . i tc !/' KCJ ^ * E 1 B C c k g m .c a l s c o m p a n y . TM -- -- ^ Mr. S. c. Giimbruno . j industrial Relations e... 23 October 1963 e^u.M.1 ***Medical Department - Plant S12 innililhit--4-- Insulation Block Dust Survey Mr. 1. H. Dickinson Mr. J. W. Perry ** Construction Insulation Shop m Mr. H. S. Eastman Mr. P. E. Henry Plant 511_________ Mr. R. A. Heal ^ ----- Mr. R. A. Huber Mr. D. R. K a t h e n y ^ "^ * Mr. B. F. King Mr. K. H. Ketchan Dr. E. M. Best tt. L; B. Weddell - Safety Dept. Dr. C. U. Demehl . Sielosed is a report n the potential insulation blocks which have townproce in"-the Construction Department's that Tharrobestcs" and Insulation Shop. The reP?rtJ 0 : ^ * ^ * * fabricated safely with existing equipment, ^ariy-Te-TO" insulation blocks cannot be f a b r i c a t e s y Mp< pile's . but that "kaylo" insulation ble=js yjr. that you will wish to ccr.?ly with 5 s : * considered,completed.. ' . _.isic If there ere eny e = e n t s , sugestione or criticism, pleas, direct * these to me. K Very truly yours, RJS:hl Enclosures i, M.D. Medical Director ' *' 'i' * '* .** r\ T ( k i s i l DlEPO. ^EXXHH.. f l L _______ zI L t l J t l KIRE.Y A. KENNNKEGCB Y c o u t r e p o r t * UNION CASSIDE CORPORATION Nuclear Division J. A. Sldd'e W. HaskinT^^ To: Messrs. T. Dougherty R. A. Miller R. Stobaeus T. R. van Fleet ee: Messrs. K. W. Lentz A. E. Pufahi ` G. S. Jordan R. F. Reichard N. J. Setter R. C. Woolery J}, A. Ridde Dr. C. U. Daraehl January Subject: ASEZSTOS TCir.COLCCY REPORT Gentlemen: t Recently several reports were given at technical meetings and summaries of them carried by the national wire services concerning possible carcinogenic, properties of asbestos. Some or you may have receives questions from your customers on this,,subject. In order to counteract any serious problems or worries ooiore t..ey get out of hand, we have ashed Dr. C. D. Damehl, Director of lo^icolegy. Union Carbide Corporation, to formulate a statement for us. .1 copy of ..is statement is enclosed. Additional copies can be obtaiaec from me or you say your own copies if you wish to pass them on to incarestea customers. .You will aoaa that, in assess, the report states that good houseacaping -- such as would be required in any dust-producing operation -- should be - ^ sufficient to prevent any problem with aabastosia. You will also note tnat he mentions use in a wet system -- which certainly applies to the papar Bill -- and a pellet form -- one of the string points of our asoestos -- aa additional mean of minimising any potantial probiam with the product. . Further, other esbestos producers and those acquainted with the sublect feel that the original data upon which tha cancer-producing report was based dia not take into account any outside influences, such as scoring or corrosive atmospheres, which also might produce cancer. Here, it snould be noted that much asbestos usage considered in the technical papers is in conjunction with tar and pitch compounds which are known to contain carcinogenic materials. _ ; '-- ' r A U 3 13 : i - - - - - - - - - - - - - - - - !&ftriMLVJUet>o,sxH.JXsL V 1 a .k e m p ;e 5 Y ; CC ;ar REPORTER . rc-e-.-.siovrep* aai fj^rio^lc physical cxaninaticgs j: .or::vrs ire Jcs irable." T;v2 c c "souid inc1ud c ^ a :se" T.-ravi T z i.-iiura" t.iat :::j vai.^r haS-rtb-chcst condition prior to work with asbestos ana to detesT.ir.o c.-.at no lung ch a n t s arc resultir.3 iron work with asbestos. it i s Relieved that the addition of asbestos at the preposed levels during checiwTtaecure of paper products would be hornless to :he_^ . 1 vconsurcr. Total dusting would have to be well ir. excess of any levels .jlM 7 acceptable to the consumer for the asbestos concentration to approach ti.e Threshold Licit Value. ' 0 In conclusion, while asbestos dust in excess of the- Threshold U n i t Value is potentially harmful, as arc cany other dusts encountered ^ ,1 - ff **r in industry, it is as readily controlled as ether such dusts and it can be used safely with appropriate precautions. Carl U. Dernehl, !!. D. Director of 7oxs.ee leg*/ K. S. Lane, M. D. Assistant Directer of Toxicology /< ' i W11tWtWM U/tAafw0 CZ3.rO0m#*Vft . 373 MS* AVZMJZ. KZW VCAK. N.V. :::;? ' i.HA,. `<T June 7, 1567 * | f f * r> s Dr. T. J. Hall Ur.icr* Carbide Europe 40, Rue Du Rhone 1211 Geneve 3 Suisse A.A. Dear Torn: I have reviewed the report, "Asbestos As A Health Hazard Ir. The United Kingdom", prepared by I. C. Sayers, and ir* general I find that I t Is reasonably accurate. 1 do not attach very much importance to the data on the incidence of asbestosis and death from asbestosis and cancer because these are merely tabulations of events and do not take into consideration the numbers of people who were subjected to the possibility of the event occurring. Vie had been interested i n the possibility that the short fiber Coalings product might have a greater hazard than the more conventional forms of asbestos because sub-micron silica has been known to cause a rapidly progressive silicosis after exceedingly brief exposure. Vie were concerned -about whether the Coallnga material' with its exceedingly fine fibril diameter might have a v similar effect in causation of asbestosis. We therefore made same preliminary studies in which the material was injected into the belly cavity of guinea pigs, rats and rabbits and also was injected intratrachealy by a method which distributes the asbestos throughout the lungs of rats. The materials injected were the standard fiber, a refined-fiber,and a long fiber obtained from Johns Manville for purposes of comparison. Ir. the i n jection study thevcoallnga refined fiber produced the most severe reaction in the belly cavity, v:herea3 the A U 3 162 uai*lm w . exit.i S . k ---- a . 0 -*. KIRBY A. fcENNNEEDY CCjar REPORTER i_____________ ,,isicr., - - 3. v : z 2 l i se rs w c iv e .^ ...; e*;-- ; cnr.s ::i-.v-- 3 cene"-..rr f?ca shia cruift teac ` -V. - ' I coalinca j r t i - s * ..Ay o _ _ f.. r i , v " :. c " - a -"' - or-5 " ! ! ? / : - S riy s'--= .,, P C -.-.. r . -u i-i-c n ni i;--.iree:eV^asi~a. . tea-..-- s -.-s w r -5 5 , *. vuiiii .... ---- -.-v*;-,-..`.1-leveca.*a.uta, aKcacs*- 5 ^ .2 V . w -*n i` M ; S ;" % ? ^ U t r 4' ..... Z & s & j S ? k 3 ^ S ^ * - * * ' . . A AA I il IT. attiss . . . . . .... f wlu ----- t a s-p fil sa .... =-; .- ,1 you you -1V . tW I r S S *.* * * ** B* ~ SM* Vsry sruW.a |MlWl / / .- > C 7V' l i U - A ^ Associasi m a c a i 0liNsor .1.' '- ' ' . TJ. S a r a 111* **a * ' V\ V r 1415 W M L S ' 13 June. 1967 Mr. Trank Dextar Union Carbide Corporation Chemicals (i Plstica Division 270, Pork Avenue Now York. N .T. 10017 R o: ASBESTOS TOXICOLOGY Door Frank: 1 osonmo yen aro owaro of tho occosienol reports concerning possible toxicity and carcinogenic properties of asbestos. Dr. Dernekl of Union Carbide Medical Department baa followed thie area very closely and has maintained a very close ebook on the working conditions at the King City plant. Perhaps the most publicity and "interest" in this problem has been in England. There, only two porta will - handle normally bagged asbestos. at the ether porta the Union of Dock i/orkers have refused to handle the shipments of asbestos. We have been permitted to bring in several shipments with not very favorable results. The last shipment, because of rather poor handling and packing, was in bad shape with many broken bags and much free asbestos. Copies of rsports on thato shipments have ondoubtedly already dome to your attention. M r. Sayers of tha asbestos group in UC1* has written a report summarising the findings and feelings concerning asbestos in she U.K. 2 assume that you have also sees a copy of this report. Zam ^ clo sin g with this letter, a copy of the comments Dr. Dumehl made in response*1 to th is'rsp o rt from England. ___ __________ My main purpose In writing this to yon is to confirm that at . . tho July asbestos meeting la Oxford we will implement the ' suggestion mads by Mr. Sayars and agreed to by Dr. Dernehl -.y ' that Union Carbido join in tho eooporatlvo standard sample : comparisons to tho extent of arranging for standard samples to be forwarded to Niagara Falls for trace element analysis. In joining tha program to tU a srtwtt we will be able to keep la dose contact with tha progress of this study and will also be aware of any adversa findings which may develop. 1 tii n m i that this 1 satisfactory to you. We will, of course, keep you directly advised of any information that may dtvdsp over here. If thase findings o r any ethara of which wo may n o u_ . ba aware cause any change in marketing plans o r programs for asbestos, we assume you will immediately advise ns. . . | tkca+ Lj. DEPO. EXH. ! l y 'T'.CY A. KENNEDY f v /* UNION CARBIDE CORPORATION 270 M* AVtNUt M W CK. N.Y. 1031* A.S5ESTCS TOXICOLOGY RZPCRT Ic has been known for cany years chat some persons working in asbestos production ware prone to uevelop a disabling lung disease. In time this condition became known as asbastosis and was related to ex posure to high concentrations of asbestos dust, viith further experience, it was found that men could work with asbestos without development of lung disease if dust concentrations were kept below a certain level, it is now generally accepted that a man can worn a 40-hour trae.t for a life time withoue developing kept at or below 5 million particles per cub.c toot os ai.. T...s dust concentration of 5 million particles per cubic loot cs air is c-a __ _ Threshold Limit Value for asbestos, and no cases or asbestosis ano to have occurred whan exposures have been maintained at or f;-1* level, despite large-scale utilization (now approaching one oillior. tons per year in the U.S.A.). This concentration of dust is generally m c visible in the average work area unless a beam or ligut causing ~y effect is present. Usually the dust concentration must be from 8-10 million particles per cubic foot before its presence is visible in aver age lighting conditions. Several years ago, it was reported that there was an increase in the incidence of cancerous tumors, especially of Jhe lung,associacea with asbestosis. Recently there have been reports of *-- wane rs occurring in individuals exposed to asbestos dust, out whouuav* . developed clinical asbestosis. It is believed by mast aut..oriw.es th t these cases have been associated with exposures significantly exceeding Si . 1 . 4 =*Jor r.mrf.ecur.r oi .b..t=. prod. trtwebi is b .s'working whtr. dust eonc.Mr.cioa w.r. noiacoiMd sc th. Threshold Limit Value. < ' Control of asbestos dust exposure is x & r d o r e heessary.^Th control methods are the standard ones applicable -to e variety of cutty. ^ ^ alterations They include d o s e d flew systems, vet processes where . possible end edequete exhaust ventilation where openings in the system , rri S c i s s S i . P i u j j i ^ , 1. soestlM. us.d " characteristics ofochervise dusty materials, where sa.is.actory con tainmenc to stay within the Threshold Limit Value is impossible, efficient end reliable respirators a r e - o - i t f d n - is protection of the employee. A program of e n v H o l b e i n - highly desirable to determine that Threshold Limit Valu dust i S l d o i . 1 paper manufacturing, it would be esirabl. to know the dust concentrations where the asbestos is dumpeo sting occurs.in lurry. Concentrations should also be determined wnere dustin, o c c u r ^ n . A0 3 y - 0 - X" finishing product*. While initial dust determinations should be made at freouent*incervals, once the level has been established as satisfactory, ^ f r e q u e n c y may be extended to occasional tests to assure continuation of a satisfactory condition. Pre-amployment and periodic physical examinations of workers are desirable. These should include chest X-rays to insure chat the worker has no chest condition prior to work with asbestos and to determine that no lung changes are resulting frca work with asbestos., It is believed that the addition of. asbescos at the proposed level* during the manufacture of paper products would be harmless to the consumer. Total dusting would have to be well in excess of any levels acceptable to the consumer for the asbestos concentration to approach the Threshold Limit Value. In conclusion, while asbescos dust in excess of the Threshold Limit Value is potentially harmful, as are many other dusts encountered in industry, it is as readily controlled as other such dusts and it can be used safely with appropriate precautions. Carl U. Oemehl, M.D. Director of Toxicology X. S. Lane, 1.D. Assistant Director of Toxicology r * *"T W. : /. /, I- .. 'jv'j^yi) ? .< > * vN .D ear Frank: . . . i "S . . . ' ` / ' ' . ...................... K ;!;}; ' * * : * . 'D u rin g a. r e c e n t c o n fe re n c e on P h y s ic and C h e m is try of . J A sbestos M in erals at O xford, E ngland, I m et with re p re - ^- ;V' . e n tativ es o f th e c ro u p who a r c c o o rd in a tin g an a n a ly tic a l - m. , i ' **_*LlDEPO. 1XH. r f rh / t i . KIRBY A. KENNEDY COURT MRORTER 1U316C A03 16 i V V UNION CARBIDE B E L G I U M N.V. RECEIVE C: 5 E? J /. fRAHGOZ 1415 /TJH/MLF . y \ Br u x e l l e s B. 30 November. 1967 . sviavi bOUtll _ 1 Mr. F . Dexter --; _ Union Carbide Corporation New York OfAee . 1 _I \ ' % Dear Frank: * As you know we have been trying to keep close to the asbestos toxicology work in the U.X. Fred Muxnpton at Niagara Falls arranged for some work to be carried out on a sample and gave, us a report on this. Ian Sayers took the report to the laboratory group in the U.K. which it co ordinating this work. Xam enclosing qf*copyjof his hand written report for your information. When they come back to us for additional analytical work we will pass it on to you. There continues to be a great amount of concern about this subject and we are going to have to learn to live with the problem in the U. K. So far there has been no indication of it being passed on to the continent. . . In this report lan passes on the request for permission . to publish our data and Xwould like your comments on this. Even if you agree we would try to find out In more detail the conditions under which this data would be presented before ^ /,, agreeing directly with them. Perhaps it would be better r 'r ' $1 to have this sort of publication A rst approved by Carl Dernehl before we Anally agree. Also Xwill ask Ian to follow directly on obtaining the speetrographlc analysis method. . . ' If you or any of the others receiving this letter have any comments Xwould welcome them. . . Best regards, tk z u ll DEPOiEXH. * Very I zM iJfr'f | K IR BY A .KKckNNNNKKIO T : . cooer fcsmBTUt truly y o u r s * ----------------------- THOMAS J. HALL, A03 i5>; T'vftvnrm h /-m S t a r t / S a H F A S & eP O B T ~ o* t//S !T ~ TO ft/e u /r * ^ o / n p s t s P e S B A B C /i t / j J t r 7 - t i - 7 CAre Ve. TTmaeet-t. /Humerons Av**-r/<vc<t M m . P & U AJoU) S A Y S T v e r B / B B P S / B d Aig C u A V B D j A P E * B S S S / B P S p 7 m b p iA /ro J.UA/GS, jT/j j b c T tro c a P y s o r s c e je e s c e a s e cpajcbp. *a/ a * 7 S T>/e rA C r TM * r~ '** P P A C T -tC B / r /s ^ s s TSe S P o n S / B B r o A ro/reA PAOOt. ' S PAoexi/ y Due Tv tre c p b a t b A B c z /r tttj/S n o tj !?a t s a s oJ*ct- A i t s Cbo / J*. .f \y>& ' *> % A03T57 ! n Building 8-96-2 S. Q. Hull, K.D particulate iiatter ia Air Asbestos Dust project So. E-PAP.-7 6-67 Dear Don: ` /.a par our telephone conversation today, I an attaching a resume1 of our determinations of dust.fer**th*d by the employees while cutting and installing "kale" insulation. Tie feelithat further air sampling is needed to give you more meaningful conclusions as to the best protection for the employees handling this material. . . At your convenience, we will be^glad to discuss these findings with you. In the meantime, if you would keep us informed of jobs pertain ing to cutting, installing and removing "kayle" insulation, it would be helpful in scheduling the air sampling work. ' Thanks, Bert liurray T T=" $'. .i i T.*5yT DEPO. EXH. J J l tW I t KIRBYf A. KENNEDY COURT REPORTER sss1 -a VV-v,!** MEMORANDUM Niagara F alls, New York September 29, 1975 To: R. E. Byrne, Or. r- B. L. Ingalls J. L. Myers M. C. Thurber , From: H. B. R h o d e s / . Copies: Subject: File V isit to the 18th International Congress on Occupational Health Brighton. England. September 14-l9i 1975 The w riter attended the above noted conference in Brighton, there . were 22 papers directly relating to asbestos presented and about another 15 on occupational lung cancer generally attributed to various particular matter such as s ilic a . Talc was covered in several of these. Abstracts of a ll papers are available and a complete se t of papers will be published in some months. ** * . The conference was Attended by over 2000 delegates, including most ' of the big names In the asbestos controversy. I had the opportunity to .ta lk informally with a number of them and th eir current views on the toxicology situation will be simnarized.- A In general, the conference produced only one bombshell in the asbestos area, a paper by Dr. H. Wassennan of Isra e l. I t was 1n a different session on Geography and Occupational Health. He took a detailed look a t about 40 mesothe lioma deaths that have-been recorded in Isra e l. There were several among small children, they were about equally distributed between men and women, a substan tia l proportion had no significant traceable occupational exposure, and the highest rates were not 1n the two regions of Israel where the plants which *handle asbestos are located. He drew occupational exposure to asbestos. the cPofn)cilrusion that the cause was non The London Times reported this prooinatAiyr/,BqUi the AlC and Dr. Muriel Newhouse wrote le tte r s of rebuttal which we- assumefyl 11 be published. Bob Mereness w ill report d e ta ils vla AIA/NA. .. . . ' v- . . r-JtfviQiS I * Overall, the'mesothelioma situ atio n fo r occupational exposure continues to look discouraging. .The McDonalds opened the asbestos session with a survey.,..^, of the available Information on the Incidence of this disease In various parts | of the world. They found the Incidence extremely high In three situ atio n s: . . | . ' H 1. Among Insulators. *%V* a? j 2. Among those who work or live In c itie s with ship yards. ' * 3.. Among thole who work or live in certain c itie s with large asbestos plants. ftuo*f 0118* _ po.exh.2J <45l KIRBYA. u :.t " V. countr,,p v .. bxjajdLIpEEPpOo,.KKXyHH..a3 ^ i KIRBY A. KENNEDY COURT REPORTER -2 The evidence for a gradation of effect for the various types of asbestos continues to be conflicting. 1 ' 1111ng operations. Here a clear pattern from cTM6* * ]* 1* chrysotile to anthophylite 1s found. They conclude that this pattern 1s generally true with sow possible exceptions. The data used 1n th is study went up to 1972. Mr. John Harsh, (RivbistQS*Ksnhatt2nl mentioned to we that there are a substantial number 2 m i i S K i "it could a lte r the rate of Incidence considerably. . The TBA paper updating th e ir was almost unbelievable. I t was read by Dr. R. Doll who awbled to fa s t th at nobody understood a word he said. I t was bached up by slides con- talnlng large tables of unreadably seall figures. Bob Hereness Is to get a copy of the paper as are a nunber of others who couldn t understand 1 t. I had the opportunity to discuss the Rochedale researches with Dr Lewinsohn. The key controversy with Dr. Sellkoff revolves around the reading of the x-rays. A panel of four. Including lerfnsohn 1* reading them and the resu lts are being correlated. A meeting to discuss tne resu lts is scheduled for January. I t looks like th is w ill not be ready 1n t i n to help 1n the U.S. OSHA revision. ' . - The discussions with lewinsohn and h1s TBA associates bTMught * out clearly another key.polnt that I do n o t l e v e ever rea lly spelled out 1n the OSHA hearings. This factory that forms the basis for the 2 fib e r lim it Is ju s t now getting th e ir fiber levels down to 2 fib ers. All o f th e ao rtalIty data th a t Is being argued over 1s for exposures well above th is . ' .. ' This point was also emphasized by Dr. Steve Holmes.(Dr. Holws te s tifie d a t the OSHA hearings.) The lim it 1s not TOO fiber - years based on an assuwd 50 year exposure. This Is tied to a' very c ritic a l second condition th at concentrations do not exdeed 10 f l f f / c e ensured over a 10-15 minute period. These c rite ria do not consider w sothelloaa. . . The TBA paper was followed by Dr. Murial Newhouse with |j*r . la s ie st thinking on her cohort of 3600 asbestos te x tile workers. She had fitte d a distribution function th a t had worked for , " dd4ti eradletlno a 10-15X death rate from wsothelloma. This was in addition S a o T f rS "SnS cancer; This Is a very substantl.l number and the re s t of the B ritish experts that I talked to questioned, the v a lid ity of the extrapolation. Interestingly enough. Dr. Sellkoff arose "* he f e lt she was high by;a factor of about 2. I t was Interesting to note in ,11 of these discussions th a t the workers had heavy exposure for a le a st :;v sow period but no real attempt was made to correlate variations In ex- .peofsfeucret . InDmr.esHoetwhehloiuosme,a.h; owever, continues to talk abou't a dose-'rtsponse x Several other papers of p articular -Interest In th is seminar related to a cooperative e ffo rt to compere asbestos fiber counts by the chnloues .used 1o various countries. The general feeling was that tne wthods l e f t considerable to be desired but 1n the light of our experiences the comparisons looked pretty- good. A key difference found was with the 01189 . -3- 0.5. PAT samples that everybodybut the and have a low. Me can understand the problem./^ethef the PAT samples are really real question in our own minds as to whether t much more than a numbers gaae. . the SelU off e t. .1 . p m r pn TOC ' ' F?TM" " ri,, bp" ie4 looked like the same data as was that*Dr. George Wright got red. on the short fib er question to the extent ^ ,, in sists that there is and climbed a ll over great deal of evidence nthoaetvitdheenycearethnatott.he O*rh.oSJte.liko' ff. himwselff fiinnealllyy had to come ovtehratantdhey saooth things out. As aconsequence. Iwas on.y . . do have additional data but could get no d e ta ils. . E p H H uti0t S S " S n U m d T n a - B S M - A 1 , caused as much esbestosls * 1cro * ` h .bush to make compensation tchlaeimnusmabfetreor fwmorinkeinrgs wfohor csiemv*eral years Vn. ,thhe. aassobeesstos minebs.ut Tuhedreidwas cborinnsgidoeruatbsleomqeubeasctikognrourend9*rodniJth5e cro^ciiddoollilttee ssiutuaationb.lu(Wahsebnetshtoesqfureosmtion Kfsu ^ r s ia a is y s t^ s i :*>. pic.-. of regulations came,, * ^ 2 1 g ta ttS S t i and chrysotile from ' South Africa would be r e p lie d b y b e tte r aying of insulation in the i,, j u j STAS!?.* great deal of concern th at 1 1 , 8 bet t er There is a growing feeling pthicattursehowrti,ll ingteetnwseoresexpboesfuoreres wi thich8to*vv5er!w h2eliimt^hee^lung cleasrhi#nrgt misecvhaagnuisems is; .I s i w s s . M a 'a*** --" i" manady bdeepeennodusghtotoa cconasideurabsle eextoentnon tthhee i^ndividu,al fisbuesrcelpimtibitilwitays, The " knew. if h . m w m . . * " " ",m ut" K3?.:pl 7M TXlWi '  ** Notion THe rretorfol msyb*rrey . tor*4 hr >*w (T'tie :7 U 5. Coda). Y A. K EK f.'H Y i t .t P!rPor.-.-:n VARIATION OF PROPERTIES OF CHRYSOTILE ; ASBESTOS SUBJECTED TO MILLING f A. M. Unger, M. S. Wolff, A. N. Rohl, I. J. Selikoff Environmenul Sciences Uboratory of the Department of Community Medicine, Mount Sinai School o f Medicine of the City University of New York, New York, New York Mechanical milling h commonly used to product short chrysotllt asbestos for experimental purposes. Such manipulation also decreases fiber crystallinity, alters Si-O and Mg-O Interlayer bonding, induces coordination changes in the brucite layer, diminishes the ability o f fiber to reduce specific free radicals and physlsorb organic molecules, end decreases hem olytic potency and antagonist sorption capabilities. The degree o f alteration Is related to the time o f milling. Results o f biological experi mentation with these materials m ust be Interpreted with caution. Interaction mechanisms In the biological setting are suggested for chrysotllt fiber. INTRODUCTION . The current U.S. federal standard for worker exposure to asbestos dust became effective on July 7 , 1972, and established, am ong other factors, m eth od s and analytical techniques for air analysis. It defined fibers to be enum erated In the work environm ent as those 5 - 1 0 0 pm in length [Federal Register, 1972). . . .. T he selection o f fibers greater than 5 pm in length was based primarily on m ethodology evaluation by the U.S. Public Health S e m c e during a study o f work environments in the asbestos textile industries in the United States (Lynch et al., 1970). This investigation was indebted to a British study b y Addingly (1 9 6 6 ), in which the 5 pm fiber was selected as the lower size lim it for counting, m ostly on a utilitarian basis: the counting procedure, by optical m icroscopy, was sim plified, and the interobserver error for counting was reduced. This latter study was also influenced by an existing theory o f pathogenesis o f asbestosis, which suggested that disintegration o f large asbestos bodies, those necessarily nucleated on long The authors Wish to acknowledge support under a Center grant from the tonP IwUtutttaJ Environment,. Health Sciences, ES 00928. On. of us. (M.S.W.) under a postdoctoral fellowship horn the NIEHS, ES 02565. The capable technical ass.stance of A. Tordinl and T. Samo is gratefully acknowledged. Requests for reprints should be sent to A. m. Langcr, Evuon, the Department of Community Medicine, Mount Sinai School of Medicine New York, Fifth Avenue A 100th Street, New York, New York 10029. i .Knntorv of unlversltv of 173 loumal of Toxicology and Environmenul Health,4:173-188,1978 Copyright C 1978 by Hemisphere Publishing Corporation 0098*4108/78/0401 -017382.25 174 A. M. LANGER ET AL. fibers, was responsible for asbestosis. Malignant tumors were not con sidered in this size selection. The use o f asbestos in som e 3 0 0 0 applications has been accompanied by increased use o f short grades o f fiber. These fibers now constitute the major size fraction used throughout the world. The question of the importance o f the fibers not counted by the current U.S. standard has recently been raised: in m ost com m ercially available, asbestos raw materials, small fibers con stitu te th e n u m erical preponderance in all samples examined (Timbrell et al., 1970); sm all.fibers tend to form stable aerosols with greater potential for inhalation; small particles penetrate beyond the terminal bronchioles and com e to rest in alveolar spaces through impaction and diffusion m echanism s (Timbrell, 1973); retention o f short fibers is marked, as evidenced by their numerical preponderance in human tissues (Pooley et al., 1 9 7 0 ; Langer et al., 1 9 7 1 , 1973; P ooiey, 1972). Som e controversy has arisen concerning the biological activity o f small fibers, mainly because experim ental evidence exists, in both animal and in vitro test system s, to support either contention: short fiber is active (e.g., King et al., 1946; Davis, 1 9 6 4 , 1 9 7 0 , 1972; H olt e t al., 1 9 6 4 , 1965; Wagner, 1968, 1973; Mclver, 1968; Gross, 1968; Suzuki and Churg, 1969; Wagner et al., 1 9 7 0; Hilscher e t al., 1 9 7 0 ; Bey and Harington, 1 9 7 1 ;P o tt et al., 1972; Wagner and Berry, 1 9 7 3 ), or sh o rt fib er is less active o r n o t active {tjg., Vorwald et al., 1951; Pott et al., 1972; Stanton et al., 1972; Stanton, 1973; Reeves et al., 1974). A review o f these papers suggested that material preparation and m anipulation played a key..role in deter mining beforehand whether a response would be induced. For example, Pott and colleagues produced longer latent periods for tumor response with ground fiber, as compared with responses produced with unground fiber; Hilscher and colleagues produced tum ors with m icrotom e-cut fiber (a relatively gentle size reduction m ethod) and found no response with ball-milled samples (a vigorous m ethod). OBJECTIVES OF THE PRESENT STUDY These and other observations suggest that conflicting results concerning the activity o f short asbestos fiber have been brought about by property alteration through m anipulation. We therefore began a study o f small fibers, _reducedL_in_size by m ethods similar to those that produced so-called biologically " inactive** small fibers. These materials were examined by means o f a number o f analytical techniques to determine whether alteration o f surface or structural properties had taken place. In addition, in vitro test system s were used to deduce any change in biological activity. _ 175 properties of chrysotile asbestos M ATERIALS USED IN THE STUDY AND THEIR PREPARATION C hrysotile asbestos occurs naturally as com pressed m ats o f short fibers w ith a large proportion o f accom panying fibrils, in several m a|or serpentine deposits in western North America. These deposits have been referred to in the mineralogical literature as the Coalinga type. Samples were obtained from the New Idria, California, deposit through the courtesy o f Union Carbide Corp. This material, referred to as Calidna R G -144, was used for experimental purposes. Impact-milling was accom plished using a Wig-L-bug am algamator, co n sisting o f a 2.5-cm -long, 1-cm-diameter steel cylinder, which could be attached to a vibrator operating at about 10 c y ! per ! o n d. Portions o chrysotile (5 0 mg) were placed in the cylinder chamber a 10 X mm pellet and milled for periods ranging from 6 0 to 3 6 0 0 s. These materials were then exam ined for changes in crystal structure, surface chem istry, and chemical and biological behavior as a function o f the duration o f ball-milling. . METHODS AND RESULTS Transmission Electron Microscopy and Selected-Area Electron Diffraction . Portions 1 mg) o f the material as received and o f the milled sam ples w ere dispersed in 0.1 ml nitrocellulose (1% in am yl acetate) on a precleaned glass slid e by gen tle stirring. A secon d slide >vas placedI over .th e first and the tw o slides were pulled apart, producing a film on each. The film was floated on water, and carbon-coated Formvar-coated grids were placed on the film . T he grids w ere lifted o u t w ith filter aP " on filter paper in a petri dish. They were exam ined by transmission electron m icroscopy (TEM) (J E O l IEM -120U) at 1 2 0 kV_ photoiraphn were obtained at direct m agnifications ranging from 2 8 0 0 to 2 0 0 0 0 directly on the TEM screen. All counting, for size distribution characten- zation, was done directly on photographs at a final fn 1 0 ,0 0 0 w ith the aid o f a Porton graticule. T w o observers part.cipated in this process, alternating counting and size recording every 1 0 counts. Som e 1000 objects were counted for each preparation. Interobserver measurements w ere made consistent by establishing counting criteria: a particle com posed o f at-leasM w o fibrils, the shorter being con .guous w.th and c o m p r isin g a t least one-half the le n g th .o f he first, was called a fiber ob jects counted as fibers possessed a length/w .dth asPe^ rat` fi, at 3 :1 , objects with smaller aspect ratios, com posed o f many fibrils., w counted as clumps; single fibrils, o f any aspect ratio, including g fibrils that did not m eet the fiber criterion, were called fibrils. FIGURE 1. Six* distribution of fibers In milled chrysotiie samples becomes profressively smaller. Electron micrographs represent fiber unmilled (A) and milled for 60 s (B), 300 s (C), and 3600 s (D). TABLE 1. Calldrla Chrysotiie: Site Distribution on Comminution as Determined by Electron Microscopy Percentage in size class Treatment < . 0.11- 041- 1.1- 2.1- 3.1- 4.1- 5.1- > Number 0.1 04 14 2.0 3.0 4.0 5.0 10.0 10.1 counted Fibers (length In micrometers) Untreated 3.7 33.7 224 18.7 74 1.4 14 3.7 04 214 60 mill 04 224 34.0 274 13.6 1.1 - 0.3 - 191 300$ mill 0.4 53.4 32.7 134 0.4 -- - 1300 mill t.6 79.1 12.4 0.9 -- -- . - - - 251 -- -- 162 3600 mill 164 S2.9 0.8 ** 123 rionis (lengm in uruns 01 micrometers/ Untreated 24.8 51.8 9.9 5 4 3.3 1.9 14 0.8 0.6 800 60 mill 1S.7 67.5 124 4.0 0.4 - - 300 mill 24.7 69.0 5 4 0.9 -- -- - 1200 mill 68.0 31.7 0.3 -- - - - 3600 mill 74.8 23.1 O.t ---- - - 779 - - 962 - - 829 -- -- 838 176 3 PROPERTIES OF CHRYSOTILE ASBESTOS 177 Progressive grinding o f chrysotile produced marked reductions in both fiber and fibril length (Fig. 1; Table 1). In the untreated chrysotile, 77% o f the fibrils were less than 0 .5 jim in length. In com parison, in the 3600*s milled sample, virtually the entire fibril population was smaller than 0.5 pm . Chrysotile fibers comprised 21% o f the population in the untreated material and were reduced to on ly 13% o f the 3 6 0 0 -s milled material. Lengths were less sharply reduced, with 95% o f the fibers less than 5 pm in length in the untreated material and over 99% o f the Fiber reduced below 0.5 pm in length in the m illed m aterial (Table 1). A lthough not included in Table 1, clum ps increased from 0.5% o f the objects counted for the untreated material to alm ost 10% o f the objects counted for the 3600-s milled material. In addition to these changes, the m illed asbestos possessed unusual morphological features that more readily deform ed under the electron beam. Although the fibril form in m illed sam ples resembles the form observed in untreated m aterial, the form er possesses more flattened internal capillaries and sustains greater damage per unit tim e under the electron beam (compare Fig. 2 , A and C). Selected-area electron diffrac tion (SAED) patterns obtained on fibers o f similar dim ension in both populations display only a small loss in intensity o f reflections and a decrease in streaking o f the (/fcO) reflection s in the m illed materials (compare Fig. 2 , B and D ). The loss o f streaking o f the (hk0) reflections may indicate a flattening in the ab plane, produced by breaking along the curved surface. These features suggested structural damage during com m inution (Langer et al., 19 7 4 ). . . Electron microscopy dem onstrated that mechanical com m inution ot chrysotile produces marked size reduction o f both fibers and fibrils, reduces the overall fiber population to fibril form , induces the form ation o f clumps, and induces structural damage to the chrysotile fibril. X-Ray Diffraction Analysis Using a Norelco X-ray diffractom eter, portions o f samples o f equal weight were poured into an aluminum sam ple holder, flattened into place with a precleaned glass slide, and subjected to X-ray analysis in the 5*o 20 range. Sample preparation induced preferred orientation o f chrysotile fiber axes in the ab plane, parallel to the sam ple holder, which enhanced the first- and second-order reflections along the c-axis stacking, specifically the (002) and (0 0 4 )-reflections. These are norm ally the tw o m ost intense reflections o f this mineral (Whittaker_and Zussm an, 1 9 56). Two important parameters o f each peak reflection normally change on size com m inution--peak intensity and w id th . Peak width increase, referred to as line-broadening, is related m ainly to particle size decreases and subsequent relaxation o f the Bragg equation for reflection reinforcement (Azaroff and Buerger, 1958). Although the chrysotile was extensively ball-milled, the chrysotile patterns show ed n o appreciable line-broadening / K*. /K FIGURE 2. Electron micrographs of chrysolite asbestos milled for 60 s (A) and 1200 s (C) and their selected-area diffraction patterns (X 66,300). In (A) fibrils are rectilinear with intact central capillary and morphology. In (C) electron beam damage is evident, some fibrils having lost the classic morphology (arrows). (D)-The-telected-area diffraction pattern for (C) shows less streaking, indicating a losvof outer fibril curvature. 17S 4, 179 PROPERTIES OF CHRYSOTILE ASBESTOS effects This may be related to the inherent size distribution o f the m aterial, in that the bulk o f the particles lie at or below the size lim it required to produce enhanced broadening effects on com m inution (A zaroff and Buerger, 1958). The factors inducing broadening, outlined in the Scherrer equation, may also be absent in the present case since the majority o f the particles are already in fibril form and com m inution m ainly affects particle length. In this case, therefore, the orientation effects are such that the ab plane remains essentially unaffected. We observed, however, a marked decrease in the total X-ray cou n t under tw o major reflections, (002) and (004) (Table 2). By using a polar planimeter to measure the areas under these reflections, the total X-ray photon count may be determined as a function o f the reflection area within 1% error. Since the m easurement was m ade from a f attened baseline with n o discernible satellite peaks, radial distribution analysis for the contribution of incoherent scattering to the baseline was not deemed necessary. The relative loss o f X-ray photons was greatest from the m ost ,n teSimHafH o sso f X-ray crystallinity for chrysotile asbestos on grinding was observed previously by Ocella and Maddalon (1 9 6 3 ). We coy b TM ' h 'sf and further observe that m echanical m illing o f ch ryso lite for period'.t o on ly 5 m in produces a m arked alteration o f its structural Integrity and decrease in its crystallinity. Infrared Spectroscopy Untreated and manipulated sam ples o f chrysotile were prepared for IR spectroscopic exam ination by pelletization in a KBr matrix (0.25 w /w ), utilizing the standard solid preparation technique. Specim ens were exam ined with a Perkin Elmer m odel 4 5 7 IR sp ectrop h otom eter in the range 2 0 0 - 4 0 0 0 cm '* (X = 2 .5 - 5 0 .0 pm ). S elected portions o f spectra for specim ens ground for 6 0 , 6 0 0 , and 360 0 s are show n .n F.g. 3 Several im portant features may be noted in Fig. 3 . T he material milled TABLE 2. Change I" Tout X-Ray Count (Peak Are) under Selected Reflection with Fro*re**lve Ball-Milling* _________________ _______ Treatment Peak area (In' ) 7.35 A (002) / ,/ / , - 100 Peak area (In* ) 3.66 A (004) I , II, 0 Untreated -7.A36O- 66..9996 60-s mill 300-* mill 7.38 6.01 1200-s mill 4.92 5.72 3600-i mill 3.50 5.69 Repeated for m ^qidealentt (pkin* ch,n*e). CuKo nickel filter; graphite monochromator; 1 28/min; -0. target; operated at 45 kV/20 mA. ISO A. M. LANGER ET AL. UNI. V ** I 600 3600 FIGURE 3. IR spectra of Calidria asbestos, untreated and after milling times of 600 and 3600 s, show the maior absorption bands unchanged. Bands at 1030 and 470 c m '', tentatively assigned to interlayer Si-O-Mg.arc broadened and shifted. at 6 0 s produced an IR spectrum consistent w ith untreated ch rysotile (Brindley and Zussman, 1959). Unmilled Calidria asbestos gave similar spectra, showing strong peaks at 368 3 cm - 1 , corresponding to the Mg-OH hydroxyl group, with a shoulder at 3640 cm *1 (probably the interlayer hydroxyl) and a triplet at 1082, 1020, and 9 55 cm " 1 , possibly corresponding to the Si-O, Si-O-Mg, and Si-0(H )-M g stretching frequencies (as suggested by IR spectra o f quartz, nem alite, heated chrysotile, and kaolin, the latter the aluminum analogue o f serpentine). The assignment o f these three absorption bands betw een 1081 and 955 cm "1 is tentative because the stretching and vibrational m odes are difficult to resolve and uniquely assign for this mineral. T w o additional triplets, corresponding to the M g-0 bonds, appear centered at 605 and 4 3 8 c m '1, the latter with tw o shoulders at 4 8 0 and 40 7 c m '1. Chrysotile milled for 6 00 and 3600 s shows a progressive broadening and a shift in the 1 0 2 0 < m " 1 peak (Si-O-Mg) to about 1005 cm " 1. The shift to smaller wave number reflects a general decrease in both strength (increasing-.bond-length) and a corresponding change in vibrational energy requirement. The shoulder at 4 8 0 c m '1 broadens and disappears on progressive milling. The OH absorption peaks (3683 and 3 6 4 0 cm *1) remain essentially unchanged. On the basis o f the observed changes in the IR absorption modes, it can be concluded that mechanical m illing alters som e o f the bonding m odes in chrysotile, especially the surface brucite layers, but significant dehydroxylation does not occur. PROPERTIES OF CHRYSOTILE ASBESTOS 181 Electron Spin Resonance Electron spin resonance (ESR) spectra were obtained on solid samples or sonicated suspensions (1 0 mg/ml) in carbon tetrachloride, using a Varian ESR-3 instrument. With all sam ples, a strong, broad resonance was observed centered at 0 = 1 .6 1 with a width o f about 850 G (Fig. 4 ). Hyperfine splitting (AW = 1 0 0 G ), corresponding to paramagnetic ion substitution in the crystalline lattice, was evident in the untreated and heat-desiccated (150C ) sam ples. Progressive milling o f asbestos fiber caused a loss o f hyperfine resonance in the ESR, consistent with distortion o f the crystal lattice. Reduced particle size may also be partly responsible for the loss o f hyperfine sp litting, since .the resonance characteristics are dependent on orientation effects as w ell. The width o f the major peak remained similar in the m illed sam ples, but the resonance appeared broadened as a result o f a reduced intensity and loss o f fine structure. The ESR spectrum o f Calidria fiber probably reflects the superposition o f tw o resonances, attributed to ionic substitution in the magnesia layers and defects in the FIGURE 4. ESR spectra of successively milled Calldrla chrysotile show progressive Ion of hyperfine structure, attributed to crystalline changes In the brucite layer. Resonances are all centered at f b 1.61. 182 A. M. LANGER ET AL. silica layer. In a chrysotile sample from another geological deposit, with different trace metal chem istries, the observed resonances (a com plex sextet at g = 2.00 and a singlet at g = 1.47) were well separated. ' A similar broadened appearance and loss o f hyperfine splitting, with retention o f the major broad resonance, was observed with Calidria chrysotile heated at temperatures below 450C . Heating in the 600-800C region resulted in a shift o f the broad resonance to g -- 2 .0 0 6 . It is generally accepted that the initial effects o f heating are dehydroxylation o f the brucite layer (200-400C ) follow ed by recoordination o f the anhydrous magnesium silicate and its subsequent recrystallization to forsterite (about 600-820C ). Thus, loss o f ESR hyperfine structure points to structural disruption o f the m agnesium -containing `'brucite" layer in chrysotile. . Hemolytic Activity and Antagonism . Portions o f unaltered and manipulated chrysotile were prepared and tested for erythrocyte membrane activity with the hem olytic test system outlined in Schnitzer and Pundsack (1970). This system for testing the membrane activity o f asbestos minerals was developed over the last 10 yr so that the different fiber types may be compared in well-defined system s (Macnab and Harington, 1967; Schlipkoter, 1968; Secchi and Rezzonico, 1 9 6 8 ). In m ost o f these test system s, mature sheep erythrocytes, in plasma-free suspensions, were tested with known quantities o f asbestos fibers and their hem olytic potency determined by optical measurement of released hem oglobin. In our stu d y, mature sheep e ^ th r o c y te s were also used to test the hem olytic potency o f known quantities o f fiber (Table 3). With an equivalent mass o f chrysotile, a marked decrease in the hem olytic potency was observed after 300 s o f mechanical milling. This was demonstrated by comparing a 1-mg/ml hem olysis level with the concentra tion o f chrysotile required to produce 50% hem olysis (Table 4 ). TABLE 3. Variation of Htmolytlc Activity with Fiber Manipulation Cylinder milling, time M Hemolysis at 1 mg/mi <%) (Untreated)- SO 300 600 1200 3600 ots*75*6 52* 1 23* 1 '12*1 12 Chrysotile concentration at 50% hemolysis (mg/ml) 0.4 0.4 1.0 2.6 4.4 IS Percent hemolysis in the presence of antagonists CMC (4 ng/tnl) PVPNO (1250|ig/ml) 21 25 38 19 29 10 19 6 11 5 6 'Standard deviation determined by 10 repeat determinations. PROPERTIES OF CHRYSOTILE ASBESTOS 1S3 TABLE 4. Adsorption of Diphenylpicrylhydrazyl (DPPH) to Chrysotile (Calidria) Milling time (>) (Untreated) 60 300 600 1200 3600 Chemisorption (pmol DPPH/g asbestos) 4.3 *1.5 6.6 * 0.8 6.9 * 0.6 7.9 1 0.6 7.0 * 0.7 3.4 * 0.7 Physisorption (pmol DPPH/g asbestos) 213*2 288* 2 192*6 Mechanical m illing o f chrysotile for 36 0 0 s produced a material that was weakly hem olytic, requiring almost 10 times more fiber than unaltered material to produce a 50% hem olytic level. Asbestos hem olysis may be antagonized by a number o f polym ers, som e o f which have been described previously (Schnitzer and Bunescu, 1 9 7 0 ). C arboxym ethyl cellulose (CMC) is a potent antihem olytic agent in th e ch rysotile h em o ly tic system . It has been proposed that the polyanion com plex becom es bound to the chrysotile fiber through interaction with the hydrogens on the surface hydroxyl groups (Schnitzer and Bunescu, 1 9 7 0 ). Other polym ers, such as polyvinyl-pyridine-/V*oxide (PVPNO), do n ot appear to interact with the same groups, so that for an antihem olytic response equal to th at o f CMC in the chrysotile test system , PVPNO m ust be used a t 1 0 0 tim es the concentration o f CMC (Table 4 ). In our test system s, CMC was tested at 4 pg/m l, whereas PVPNO was tested at 1250 pg/m l. With CMC a t 4 pg/m l, PVPNO at 1250 pg/m l, and asbestos at 1 m e/m l, varying antagonist response was observed. The antihem olytic effectiv en ess o f CMC decreased In the sam ples that were progressively m illed, reflecting the reduced hem olytic potential o f the milled asbestos. T h e h em o ly tic antagonism was alm ost elim inated in the 36 0 0 -s m illed material (Table 3). The same effect was observed for the PVPNO. Both phenom ena suggest that the brucite layer o f chrysotile is progressively disordered on mechanical milling, altering the effects and the ability o f polym ers to adsorb to its surface. Organic Free Radical Adsorption Diphenylpicrylhydrazyl (DPPH), a stable organic free radical, is strongly adsorbed to chrysotile asbestos, a phenomenon attributable to strong interaction w ith -th e polar-nitro groups and nitrogen groups (M. W olff, unpublished data). The adsorption is tw ofold, an irreversible chem ical adsorption resulting in reduction o f DPPH to the hydrazine, and a multilayer physisorption that may involve vertical or horizontal stacking o f the molecule. Chemisorption probably occurs via the hydrogen atom from the surface brucite layer, similar to the DPPH reduction reported y aromatic phenols and amines. IM A. M. LANGER EY AL Chemisorption potential was measured by titration o f 50-mg samples o f asbestos in carbon tetrachloride with DPPH (1 0 " s M in CCI), until excess DPPH could be detected visually by its purple color in the supernatant. Results are given in Table 4 . Physisorption was measured by determining the adsorption isotherm. Asbestos samples **4 nl* m ixed with portions with varying concentrations o f DPPH (1 0 " -1 0 M in CCI4 ) overnight in a-shaker. The DPPH remaining in th e supernatant was measured spectrophotom etrically (530 nm). The isotherm was deter mined by regression analysis o f m illim oles adsorbed per gram asbestos versus equilibrium concentration o f DPPH. The values, given in Table 4 , were calculated by extrapolating the adsorption isotherrn to 10" M. Chemisorption was increased by ball-milling the chrysotile for 6 0 s, reflecting the increased surface area available for adsorption. However, milling for longer periods, up to 1 h, significantly reduced the chem isorption capacity o f chrysotile. A similar reduced potential for physisorption was observed on prolonged milling. Both o f these processes can be attributed to interactions at the surface o f the chrysotile fiber. Thus, brief milling produces fiber with a greater surface area, relatively unchanged in terms o f chem istry. In this state, chem isorption is increased. Prolonged milling appears to degrade the surface brucite layer and disrupt the uniform proton distribution (hydro gens on the brucite). Both adsorption processes are dependent on inter action o f the outer hydrogens and adsorption is therefore reduced by the structural degradation that follow s prolonged mechanical milling. DISCUSSION AND CONCLUSIONS An asbestos fiber standard, establishing a threshold lim it value (TLV) for fiber exposure to workers engaged in handling asbestos-containing dusts in the United States, was established at 2 fibers/m l on July 1 ,1 9 7 6 . The fibers, counted by light optical m ethods, were to include only those longer than 5 jim. Over 3 0 0 0 uses o f asbestos exist In the United States, which indicates that a range o f materials, processing o p e r a t i o n s ,^ fabrication plants are involved in supplying society w ith these products. The size distribution characteristics o f the aerosols generated in these work areas must, therefore range greatly. In addition, the exploitation o f new types o f asbestos deposits, primarily those in the western United States and Canada,_have introduced a material that consists alm ost entirely o f short fibers. The need to establish the biological potential o f short fibers is therefore critical. .. A number o f studies o f human lung tissues dem onstrate that small particles predominate in the fiber burden o f such tissues and may be implicated in human disease (Pooley e t al., 1970; Langer e t al., 1971, PROPERTIES OF CHRYSOTILE ASBESTOS 1tS 1 9 7 3 ; Miller e t al.*, 1 9 7 5 ). In addition, w hile som e animal studies over the past 3 0 yr have supported the human observations, in other experim ental efforts small fibers appeared to have different degrees o f activity. in studies using short fibers obtained by less vigorous m ethods, such as air-elutriation and water fractionation, significant responses in animals were observed. In studies where fibers were reduced in size by vigorous mechanical m ethods, either n o o r significantly reduced responses were observed. Com m inution undoubtedly altered the crystal and chemical properties o f the material, it appears that the less mechanically degraded the surface o f the fiber, the greater the biologic?! response. Previous investigators have reported reduced crystallinity (Occella and Maddalon, 1963; Reeves et al., 1 974), m odified crystallinity, and reduced biological activity (Robock and Klosterkotter, 1971; Reeves et al., 1974) in m illed fiber. Our data support and am plify these conclusions. The crystallinity o f chrysotile was reduced in proportion to the length o f milling tim e. The nature o f the altered crystallinity appears to be confined to shifts in interlayer bonding betw een the brucite and silica sheets, and changes in hydroxyl configuration (but not quantity or bond strength). Supporting these conclusions are the follow ing observations: 1. R educed total X-ray p h oton s, In selected reflections, w ithout line broadening; 2. Increased susceptibility to damage by electron bombardment; 3 . Changes In SA E D patterns, decreased streaking o f (hk0) reflection s, suggesting relaxation o f fibril curvature; 4 . R etention o f intensity and location o f OH absorption bands; shift and broadening o f absorptions assigned to interlayer Si-O and Mg-O bonds with retention o f all other significant Si and Mg bond absorptions; 5 . Loss o f hyperfine splitting and intensity in the ESR spectrum attributed to coordination changes in the brucite layer. Changes in surface chem istry accom pany the reduction in crystallinity. T h e ability to reduce DPPH to the hydrazine and to physisorb DPPH is lowered with milled fiber, and these are probably both surface, stereo chem ically controlled phenomena. Hemolytic potency, often considered a surface-related even t, is also markedly decreased in proportion to milling tim e. This is not related to exposure to the silica layer, in that neither h em olytic p o ten cy nor antagonism by PVPNO is increased with milling tim e; instead, they are reduced. The diminished surface activity o f chrysotile suggests a surface structure with a distorted proton and/or magnesium ion orientation. Membrane activity in cells (both erythrocyte and m acrophage) is reduced, and this interaction may be the initial biological response. After phagocytosis, a fibrotic and cytotoxic response may follow slow degradation o f the chrysotile intracellularly, exposing the 1S6 A. M. L A N G E R ET AL. silica surface, which stim ulates collagen form ation. Therefore a reduced response, or a longer tim e needed to produce a response, is expected for milled fiber compared with unmilled fiber. Indeed, this has been observed (Reeves et al., 1974; Pott e t al., 1972; Klosterkotter, 1968; Hilscher et al., 1970). This theory intim ates, furtherm ore, that there would be a faster fibrotic response to silica exposure than to chrysotile exposure, and epidemiologic evidence supports this theory; there is, for example, no "acute asbestosis" to mimic acute or accelerated silicosis (Ziskind et al., 1976). Theoretical and experim ental consideration has been given to inter* ference o f asbestos with cellular oxidation-reduction (redox) equilibrium processes, the experim ental evidence concerning oxygen consum ption in relation to both mineral-treated macrophages and fibrotic response in animals (Bey and Harington, 1971; Robock and Klosterkotter, 1971; Chvapil and Peng, 1 9 7 5 ). Flowers (1975) has noted the critical role o f Fe** ^ F e3+ equilibria in determ ining fragile cellular energy dynamics and enzym atic transform ations. Participation o f chrysotile asbestos in redox activity in biological system s m ay be predicted from chemical and physical data: the ESR spectrum and the luminescence spectrum o f chrysotile; the reduction potential for TTC (R obock and Klosterkotter, 1971) and DPPH; and the oxidation potential for other organics (M. Wolff, unpublished 1 data). Whether these properties are related to fibrosis or carcinogenesis is purely speculative, but Allison (1973) has noted that "crocidolite, the blue colour o f which is due to charge transfer, has little cytotoxicity." Indeed, most minerals possess distinct ESR spectra as well (R obock .and Kloster- kbtter, 1971). T he hyp oth esis that particle shape is the major etioiogic mechanism in fibrotic or carcinogenic responses appears, in terms o f these considerations, to be som ewhat oversimplified, except insofar as morphology reflects more fundamental structural and surface physicochem ical properties. Further, comparison o f biological potentials o f fibers o f different lengths should take into account alterations o f characteristics o f the fibers by the preparation o f ^ i^ '.varying size fractions. REFERENCES . , . .... . *:. . 'T- ::'1" ! ;* . ' Addlngly, C G. 1956. Asbestos dust end Its menuremenu Ann. Occep. H yp 9:73-82. Allison, A. C 1973. Experimental methods-cell and tissue culture: Effects of asbestos particles on macrophages, mesothelial cells and fibroblasts. In Biological Effects o f Asbestos. IAKC Conference, eds. 9. Bogovskl, |. C Gilson, V. Timbrell, and ). C. Wagner, voL t , pp. 19-93. -. Lyon, France: International Agency for Research on Cancer. Axaroff, L. V. and Buerger, M. J. 195S. The Powder Method In X-ray Crystenography, p. 342. New York: McGraw-Hill. Bey, E. and Harington, |. S. 1971. Cytotoxic effects of some mineral dusts on Syrian hamster peritoneal macrophages./. Exp. Med. 133:1149-1199. ' PROPERTIES OF CHRYSOTILE ASBESTOS t87 Brindley, G. W. and Zussman, |. 1919. Infra-red absorption data for serpentine minerals. Am . Mineral. 44:185-188. Chvapll, M. and Peng, Y. M. 1975. Oxygen and lung fibrosis. Arch. Environ. Health 30:528-532. Davis, |. M. G. 1964. The ultrastructure of asbestos bodies from guinea-pig lungs. Br. /. Exp. Pathol. 45:634-649. ' Davis, M. G. 1970. Further observations on the ultrastructure and chemistry of the formation of asbestos bodies. Exp. Mol. Pathol. 13:346-358. Davis, ). M. G. 1972. The flbrogenic effects of mineral dusts injected into the pleural cavity of mice. Br. /. Exp. Pathol. 53:190-201. Federal Register, 1972. Standard for exposure to asbestos dust. 37(110):11318. Flowers, E. 1974. Relationship between exposure to asbestos, collagen formation, ferruginous bodies and carcinoma. A m . ind. Hyg. Assoc. /. 35:724-729, Grose, P. 1968. The production of hmg cancers in rats with chrysotle dust, in Proceedings, Internationale K onferem Ober die biologischen Wirkungen das Asbestos, April 22-2$, 1968, eds. Holstein and Anspach, pp. 244-245. Dresden, East Germany: Deutsche Zentralinstitut fur Arbeitsmedizin. Hilscher, W., Sethi, S., Friedrichs, K. H.,and Dott, F. 1970. Zusammenhnge zwischen Asbestose und Faserlange. Naturwissenschaften 57:356-357. Holt, Pi Mills, |., and Young, D. R. 1964. The early effects of chrysotile asbestos dust on rat lung. /. Pathol. Bocteriol. 87:15-23. Holt, P i Mills, J i and Young, D. R. 1965. Experimental asbestos with four types of fibers: Importance of small particles. A tm . N .Y . Acad. Sei. 132:87-97. King, E. |., Clegg, |. W., and Rae, V. M. 1946. Effect of asbestos, and of asbestos and aluminum on the lungs of rabbits. Thorax 1:188-197. KlosterkBtter, W. 1968. Experimentelle Untersuchungen Ober die Bedeutung jder Faserlnge fr die Asbestfibrose sowie Untersuchungen Ober die Beeinflussung der Fibrose durch Polyvinylpyridin- N-oxid. In Proceedings, Internationale Konferenz Ober die biologischen Wirkungen des Asbestos, April 72-35, I960, eds. Holstein and Anspach, pp. 47-51. Dresden, East Germany: Deutsche Zentralinstitut fr Arbeitsmedizin. Unger, A. M., Sclikoff, I. )., and Sastre, A. 1971. Chrysotile asbestos In the lunp of persons in New York City. A rth . Environ. Health 22:348-361. Unger, A. M., Ashley, R-, Baden, V., Berkley, C , Hammond, E. C., Mackler, A. D., Maggiore, C .)., Nicholson, W . R o h l , A. Ni Rubin, I. Bi Sastre, A., and Selikoff, 1.1.1973. Identification of asbestos in human tissues. /. Occup. Med. 15:287-295. Unger, A. M., Mackler, A. D i and Pooley, F. D. t974. Electron microscopical Investigation of . . asbestos fibers. Environ. Health Perspect. 9:63-80. ' Lynch, J. R., Ayer, H. E., and Johnson, D. L 1970. The interrelationship of selected asbestos exposure indices. A m . Ind. Hyg. Assoc. /. 31:598-604. " Macnab, G. and Harington, J. $. 1967. Hemolytic activity of asbestos and other mineral dusts. Nature (Lond.) 214:522-523. . .. .r 'M clver, F. A. 1968. Results of Inhatatioit'exposure of dogs to chrysotile asbestos. In Proceedings, Internationale Konferenz Ober die biologischen Wirkungen des Asbestos, April 37-25, 1968, eds. Holstein and Anspach, pp. 81-82. Dresden, East Germany: Deutsche Zcntrailnstltut fr ` Arbeitsmedizin. Miller, A., Langer, A. M, Telrsteln, A. S., and Sclikoff, I. J. 1975. "Nonspecific" Interstitial pulmonary fibrosis: Association with asbestos fibers detected by electron microscopy. N. Engl. / . Med. 292:91-93. Occclla, E. and Maddalon, G. 1963. X*ray diffraction characteristics of some types of asbestos in relation to different techniques of communication. Med. Lav. 54:628-636. Pooley, F. D. 1972. Electron microscope characteristics of inhaled chrysotile asbestos fiber. Br. J. Ind. Med. 29:146-153. P o o ley , T. D ., O ldham , P. D ., U rn, C hang-H yun, and W agner, |. C. 1976. The d e te ctio n o f u l x i t o l In IW A.M. LANCER ET AL. tliiitti In Proceedings o f the International Conference o n Pneumoconiosis, Johannesburg, ed. H. A. Shapiro, pp. 108-116. New York: Oxford. fou, F., Huth, F., and Friedrich, K. H. 1972. Tumor* of rats with i.p. infections of powdered chrysolite and benzol*|pyrene. Zentralbl. Bakteriol. lOrig-J 155:463-469. Reeve, A. L. Puro, H. E., and Smith, R. 1974. Inhalation carcinogne* from various form of asbestos. Cnviron, Res. 8:178-202. Robock, K. and Klosterkbtter, W. 1971. Biophysikalische Untersuchungen zur Wirkung von Asbestosen. In International Pneumoconiosis Conference, pp. 241-147. Bucharest: Apimondia. Shlipkoter, H. W. 1968. Animal experiments and in vitro studies of asbestos dust. In Proceedings, Internationale K onfereni liber die Biologischen Wirkungen des Asbestos, April 22-25, 1968, eds. Holstein and Anspach, pp. 67-74. Dresden, East Germany: Deutsche Zentralinstitut fr Arbeitsmedizin. . . ,, . . Schnitzer, R. J. and Bunescu, G. 1970. Polymers as selective antagonists of hemolytic asbestos fibers. Arch. Emdron. Health 20:4g1-482. Schnitzer, R. |. and Pundsack, F. L. 1970. Asbestos hemolysis. Environ. Res. 3:1-13. Seechi, G. C. and Rezzonico, A. 1968. Haemolytic activity of asbestos dusts. Med. Lav. 59:1-5. Sunton, M. 1973. Some etiological considerations of fibre carcinogenesis. In Biological Effects o f Asbestos. IARC Conference, eds. P. Bogovskl, J. C. Gilson, V. Timbrell,and |.C . Wagner, vol. 8, pp. 289-294. Lyon, France: International Agency for Research on Camxr. Stanton, M.. Blackwell. R., and Miller, E. 1972. Experimental pulmonary carcinogenesis with asbestos. A m . Ind. Hyg. Assoc. J. 30:236-244. ... Suzuki, Y. and Churg, J. 1969. Structure and development of the asbestos body. Am. J. Patnor. Timbrell, V. 1973. Physical factors as etiological mechanisms. In Biological Effects o f Asbestos. IARC Conference, eds. P. Bogovskl, |. C. Gilson, V. Timbrell, and |. C Wagner, vol. 8, pp. 295-303. Lyon, France: International Agency for Research on Cancer. Timbrell, V,, Pooley. F. D., and Wagner, |. C 1970. Characteristic* of respirable asbestos fiben. In Proceedings o f the International Conference on Pneumoconiosis, Johannesburg, ed. H. Shapiro, pp. 65-70. New York: Oxford. . . . .. VorwaldTA. J.. Durkan. T. M., and Pratt, P. C. 1951. Experimental studies of asbestos.. Arch. Ind. W a* ^f |.TT968.*Exlriil!'nul tumors In rats following Intrapleural Inoculation of asbestos. In Proceedings, Internationale Konferenz ber die Biologischen Wirkungen des A sbestoe , A p n l 22-25, 1968, eds. Holstein and Anspach, pp. 223-226. East Germany: Deutsche Zchtralinstltut fr Arbeitsmedizin. , ,,. Warner I C. and Berry, G. 1973. Information obtained from animal experiments. In Biological ^ V f L o f A s b e Z lA R C Conference, eds. P. Bogovskl. |. C. GBson. V. Timbr.il, and ,. C. Wagner, vol. 8, pp. 285-288. Lyon, France: International Agency for Research onpln" rWagner, |. C., Berry, G. and Timbrell, V. 1970. Mesothelioma* I fats following * e Intrapleiirt " (ngryistiM of asbestos. In Proceedings o f the International Conference o n Pneumoconiosis, Johannesburg, ed. H. A. Shapiro, pp. 119-122. New York: Oxford. ` ,. Wagner, |. C , Berry, G., and Timbrell, V. 1973. Mesothellomata in rals after Inoculation with asbestos and other materials. Br. J. Cancer 28:173-185. Whittaker, E. J. W. and Zussman, J. 1956. The characterization of serpentine minerals by x-ray diffraction. Mineral. Mag. 31:107-126. Zisklnd, M., Jones, R. N., and Weill, H. 1976. Silicosis (state-of-the-art). Am. Rev. Resp. Dis. 113:643-665. Received October 6, 1976 Accepted November II , 1977 :4 Ptj S A a m m &Q&W O q q September 1, 1972 UNION CARBIDE CORPORATION 4625 ROYAL AVENUE NIAGARA FALLS. NEJiTTDfTK 1432N. TELEPHONE:(71$) 278*337$ ( / ) PRODUCT: Chrysole Asbestos TRADE NAMES: **Clidrii" Asbestos CHEMICAL FORMULA; Mga(OH)8Si4Q10 BOILING POINT AND MELTING OINT: Not Pertinent SPECIFIC GRAVITY (HaO1): 245 VOLATILE CONTENT: AbsorbedWater.1- 4%By Weight. Structural Watar Approximately 13%by Weight. Material is not Combustible. No Fire or Explosion Hazard. INERT MATERIAL: No Decomposition or polymerization Conditions. - __________ -- ................-- PERMISSIBLE EXPOSURE TO AIRBORNE CONCENTRATION: The current standard of the Occupational Safety and Health Act of 1970 contains the following exposure The 8-hour time-weighted average airborne concentration of asbestos fibers towhich employees areexposed shall not exceed 5 fibers per milliliter greater than 5 microns in length, as determined by the membrane filter method at 400-450X magnification (4 millimeter objective) phase contrast illumination. No employee shall be exposed at any time to airborne concentrations of asbestos fibers in excess of 10 fibers per milliliter, longer thanSmicrons." (Federal Register ---Vol.3ZJhjne7^J972^P*ge^11320)^^^^^^^^^^ _ EFFECTS OF OVER EXPOSURE: Prolonged over exposure'may result in lung damage, _____ f TiTflMr*lfiTiiwr-- ---- --- STEPS TO BE TAKEN IF MATERIAL IS RELEASED OR SPILLED: spilled material by vacuum cleaner or-by water-wash. , Q Avoid inhalation of dust. Remove WASTE DISPOSAL METHOD: lj If reasonably foreseeable handling will not produce airborne concentrations in excess of **JJ"[* C no special procedures are required. When limits are likely to be exceeded, waste an serao * ibeMtd~ ana disposed of in impermeable sealed bags or other closed, impermeable containers,________ _ 1 :7 %L .. . . Union Carbide Corporation assumes no responsibility and makes no warranty, expressed or implied, repre- y/VV^sentation. promise, or statement asto completeness, accuracy, or currency of any data prov.oeo. .< s? y ..