Document wDDOw2zB8wxymZgNrpMpx2ozd

PLAINTIFF'S EXHIBIT ' i`5r mWINDSOR MINERALS INC r<<j>l5.0. f-JO \A` I or. Vcnnr-r.! >c:io-j September 7, 1977 Bondex International 3616 Scarlet Oak. Boulevard St. Louis, Missouri 63122 Attn: Ms. Jeanette Garner Purchasing Agent Dear Ms. Gamer: In response to your letter of September 1, 1977, I am writing to assure you of the quality of our products regarding contamination with hazardous mineral species. I am enclosing a copy of the Material Safety Data Sheet for our Grade TC-100 Talc and, in addition, a copy of a recent opinion conducted by N10SH which concerned itself with the quality of our ores and products. This particular section of the NIOSH study was done by Harvard University, and I have taken the liberty of enclosing a copy of the final report which they presented. The report, as you will note, indicates the absence of hazardous fiberform minerals and, additionally, an extremely low level of quartz. If we may be of further assistance in this regard, please do not hesitate to contact the writer. Yours very truly, WINDSOR MINERALS INC. ft, V?> RNM:ab Encs. R. N. Miller President BON-01521 U.S. DjrARTMENT OF LABOR Occupoi-':,n;:l Safety and Health AtJmmictration -Mi AlU./wiw | - (jt N*. 4 1 . ! ?R7 MATERIAL SAFETY BATA SHEET Required undet USDL Safety and Health Regulations for Ship Repairing, Shipbuilding, and Shipbreaking (29 CFR 1915, 1919, 1917) SECTION 1 MANUFACTURER'S NAME Windsor Minerals, Inc. EMERGENCY TELEPHONE NO. 802-484-7761 *T.'o'T'S'ox"%SV;SVi nilsor'i'^VT CHFMlCAl. NAME AND SYNONYMS Magnesium $.i 1 l_Q.ate-Hydrpu5 CHEMICAL FAMILY Silicates - Carbonates 05089 j TRAOE NAME ANO SYNONYMS 1 Grade TC 100 Talc |FORMULA . n 1H2 Mg3(Sl3)4 . * SECTION II - HAZARDOUS INGREDIENTS PAINTS. PRESERVATIVES, & SOLVENTS % TLV (Units) ALLOYS AND METALLIC COATINGS PIGMENTS HAST METAL CATALYST ALLOYS VEHICLE SOLVENTS ADDITIVES METALLIC COATINGS PILLTR Mr TAL PLUJ l DATING OR CORE FLUX OTHERS OTHERS HAZARDOUS MIXTURES OF OTHER LIQUIDS. SOLIDS, OR GASES TLV X (Units) k TLV X (Units) DOES NOT APPLY ro 00 BON-01522 B0D-tf<f0ffiJtF-ipply VAfHcOoRpPsRESnSnU.RtE (ammppHl.yl VA(Wte,^Nfi,61:tAatib>l v soWSi5,ruUTTER appfahance and odor SECTION III PHYf- . DATA SPI Cl '- AVITY (H2C* 1) BPYERVU- L* . VOLATILE Does n)t apply CVA," (-- - ___ .2) Does not apply SECTION IV - FIRE AND EXPLOSION HAZARD DATA FLASHPtHNI (Method used) _. flBl.tMXBLE LIMITS , Does not apply_____ j Does..not apply exTirtr.uisniNc: media _D_qes not_apply____ SPECIAL FIRE FIGHTING PROCFOUKES ..... ........ . _ ^______ Does _not appjy..... Lei UNU.C.UA| FlHi ANO fXPLOSION HAZARDS ________ _P_o e s,,n o t a p.p ]_y________________ _____ _____ Uei PAGE n) (Continued on reverse Form OSHA-20 Rev. May 7* SECTION V - HEALTH-HAZARD DATA , THRESHOLD limit value _ I 20 Mq/M3 __ ,_________ _________ "EFIECTSOP OVEREXPOSURt ___ Dust inhalation__________________________________ EMERGENCY A.NO FIRST A.IO PROCEDURES _____ _____ L e a y e_ a usty are a Wear approved respir.a tor SECTION VI - REACTIVITY DATA STABILITY UNSTABLE CONDITIONS TO AVOID STABLE X _INCOMPATA8IUIY 1Materials to avoid) Does not apply HAZARDOUS DECOMPOSITION PRODUCTS Does not apjny HAAROOUS POLYMERISATION MAY OCCUR will not OCCUR CONDITIONS TO AVOID X SECTION VII - SPILL OR LEAK PROCEDURES STEPS TO BE TAKEN IN CASE MATERIAL7s RELEASED OR SPILLED _____________ Does not apply _____________ Dry solid_______ WASTE DISPOSAL METHOD V* * * SECTION VIII - SPECIAL PROTECTION INFORMATION RESPIRATORY PRWOTeECaTrIONap{SppercoifVy tevpatt) mask..i.f..above A..C.G.1.H. exposure .leve.l VENTILATION LOCAL EXHAUST SPECIAL mechanical (Cencral) AAA PROTECTIVE GLOVES Not required OTHER PROTECTIVE EQUIPMENT OTHER EYE PROTFf.TION Solid p articulate * SECTION IX - SPECIAL PRECAUTIONS PRECAUTIONS TO BE TAKEN IN HANOLINgTanD STORING OTHER PRECAUTIONS PAGE (2) GPO 9 V-'.fi Form OSHA-20 Rtv. Miy 72 BON -01523 July 25, 1977 Dear Sir: We have recently and cooperatively participated in a study by The National Institute for Occupational Safety and Health (NIOSH). In this study, environmental sampling was conducted in our mines and mills. The samples taken in our operations were analyzed for their mineral content with particular reference to quartz (Si02) and asbestos. A final report on this phase of the NIOSH study was presented at a meeting of The American Industrial Hygiene Association by Harvard University who was the contractor for NIOSH. The study, while particularly concerned with dust exposure, verified the absence of contamination by undesir able mineral species in'our ores. I have enclosed a copy of the report for your records, and for use in responding to questions from regulatory agencies. If you have any questions in this regard, please do not hesitate to contact the writer. Yours very truly, WINDSOR MINERALS, INC RNM:rg Enc. President BON -01524  w* I' EXPOSURE TO INDUSTRIAL TALC IN VERMONT TALC MINES AND MILLS M. G. Boundy, K. Gold, and W. A. Burgess Harvard University Boston, MA - J. M. Dement NIOSH Cincinnati, OH (For presentation at AIIIA Cinference at Nev; Orleans, May 26, 1977) BON-01525 Introduction An environmental study of the Vermont talc mines and mills was undertaken in support of a concurrent epidemiological study of talc workers. Since geological studies dating to the early 1900*s have shown that the Vermont talc deposits contain no asbestos and little quarts, ;. ' this population represents a * group of talc workers employed in mining and milling operations who have no association with these two fibrosis producing minerals. Therefore, the intent of this study was to verify these geological-reports by quantitating the personal dust exposures of these talc workers and by identifying the mineral content of this ''clean*' talc ore. Mineralogy Pure talc mineral is a hydrous magnesium silicate with the theoretical formula 3Mg0.l*Bi02*H20 . and consists of a brucite sheet containing magnesium iGns sandwiched between two weakly * held silica sheets. This mineral is extremely soft and slippery and has a hardness of 1 on the Mohs scale. .However, as used industrially, the tern .".talc" refers to a mixture of minerals that meet certain physical requirements rather than one v?hieh has a fixed chemical composition. Industrial grades of talc usually contain chlorites which are sheet silicate minerals containing magnesium, iron, and aluminum,and carbonates which include BON-01526 \* * v/ magnesite, dolomite, and calcite. Quartz, iron oxides, serpentine tk (one of the minerals from which talc evolved) and tremolite, may also be'present. Therefore, since the constituents of industrial . talc vary in their mineral and fiber content the ensuing product has a considerable range in hardness and particle shape which contributes to its versatility. t Field Study The three major Vermont talc companies were surveyed in Summer 1975 and Winter 1976 and a total of 312 personal respirable mass samples were taken. Half of these samples were analyzed for free silica content by infra red spectrophotometry, and 20# by x-ray diffractioni Fifty-seven parallel fiber samples were taken using Millipore and Nuclepore filters. Fiber counts were per formed on these samples using phase contrast at I}'37X, and scanning electron microscopy at 5000X magnification, respectively. In addition, bulk samples from representative milling and mining operations were collected from each location. These specimens were analyzed qualitatively by x-ray diffraction for their mineral constituents- : ~` . .. The three Vermont companies obtain their talc ore, which occurs in compact lenses, by underground and surface mining. For the underground mines an inclined shaft (SLIDE) is sunk to the deposit and a heading is begun. Entry is via the same skip in which the .ore is removed (SLIDE). The depth of the BON -01527 'V mines ranges from150-BOO feetand the temperature is approxi mately 7C yearround. The mines arc always wet from the seepage of wat&r from the surface and underground springs (SLIDE). The tunnels are made by a track drill (SLIDE) through non talc areas. This rock is wasted and this process was not in operation during our surveys. A heading is mined by wet drilling, blasting, machine i mucking, and stoping methods. A drilling crew of one or two men make the holes in the working face of the ore. At the end of a shift explosives are inserted and set off in the holes to break apart the mass of ore. The following morning mechanical muckers (SLIDE) or bobcat machines (3 SLIDES) Ere used to load the ore onto the haulage cars. Pneumatic jackhammers (pavement breakers), may be necessary to break up the large boulders. Stoping methods (SLIDE) are used to remove the ore from distant pockets via a series of horizontal or inclined workings in the ore veins. In such areas a "scraper" will operate a mechanical drag which Is suspended from a 'cable aind secured to a distant I wall, to pull the blasted ore into an excavated chute (SLIDE). After filling the cars the trainman drives the locomotive to the shaft (SLIDE) where the ore is dumped into a skip, (SLIDE) hoisted to the surface or the 1st level by the skippy hoist operator. (SLIDE) The ore is then dumped and transferred again, hoisted to the surface, and transported by trucks to the-mill. In addition one company operates two walk-in niines ana an open pit mine where the ore is mined by an automatic mining BON -01528 operation. A diesel powered machine removes the rock from the face and loads it onto a truck via a conveyor in a continuous motion. An operator controls the location and movements of the cutting head v;hich cuts away at the ore face in a circular motion. A gathering arm at the front of this machine draws the ore onto the conveyor which carries the ore to a diesel-powered dumptruck. Talc Hilling t The milling processes at the three companies are rather similar. With only one exception, the Vermont mills are large, drafty barn-like structures. The ore arrives at each mill from the mine by truck and is dumped into a pit or an ore storage bin (SLIDE). A crusher .operator, (3 SLIDES) using a conveyor system or the same type of mechanical scraper as In the mine stopes, draws the ore into a jaw crusher. The ore may pass through a series of screens or a secondary crusher before being dried and proceeding to the mills. Depending on the final particle size and grade of the product, the ore may be further ground in a pebble mill or pulverized In a roller mill (SLIDE) v;here spring-loaded rollers rota^fe-e against a horizontally fixed steel ring. An air classifier system then separates the ore \ according to particle size, and this material is either bagged directly or held in storage slios. Two of the companies further purify and grind the ore using a flotation process to separate the mineral talc from the mag nesite and non-talc minerals. A slurry of the ore in water fill BON-01529 i* ' V flotation colic in which bubbier; arc created by reagents and an air injection cystem. The talc becomes attached 'to the air bubbles- arii rises to the surface as-a irdneralized froth. Rotary blades gently push the bubbles Into troughs. The recovered talc is thickened, dried, and stored in bins until bagging or shipment in bulk. Most of the product is chipped in 50-60 pound bags. (2 SLIDES' The bags are h&nd*placed on support holders and are automatically filled, sealed and discharged onto a conveyor. The conveyor leads to a palletizing area (SLIDE) where two men stack, the bags on pallets which are then loaded onto railroad cars or trucks by a fork lift operator (SLIDE). Usually the bagger and palletizers form a three-man team and rotate jobs on a half-day cycle. ` In addition, some talc may be shipped in bulk form by rail or truck. Bulk Sample's Bulk samples consisting of ore chunks from the mines or crushing operations at the mill and mineral mixtures or products from the mills were obtained from each company. Each bulk * I* sample was ground, driet}, and scanned qualitatively by x-ray diffraction. For .all the samples, talc and magnesite are found In major amounts, chlorite and/or dolomite are minor constituents, and dolomite, calcite, quartz,' biotite, ankerite, chromite, , oligoclasc, or phlogopite may be found in*trace quantities. (Table Quartz was present in trace amounts in 152 of these samples and petrographic microscope analysis, analytical transmission electron microscopy," and x-r.ay diffraction with step-scanning revealed no asbestos in these samples. BON -01530 Over 300 personal respirable mass samples were taken using 10 mm 2-stage Nylon cyclones at a flow rate of 1.7 liters per minute. The respirable dust exposures of underground miners are shown in Table 2 (SLIDE). These exposures are classified by job and company and the highest dust concentrations occur at Company B. The ore in this mine Is relatively hard and the extensive drilling and jaclchammering operations require^ to break apart 1 the large boulders may account for the higher dust levels. Jobwise, the highest concentrations are experienced by the drillers, scraper, bobcat, and mucker operators, and laborers. Scraper, bobcat and mucker operators are involved in the movement of blasted ore into an excavated area or directly into the haulag cars. The confinement of their work areas and the necessity of.using pneumatic-jackhammers may.contribute to their exposures. Maintenance'men and laborers are the "trouble-shooters" and their work and dust exposures may change on a daily basis. The average.respirable mass dust exposures for workers in the open-pit and walk-in mines are presented in Table 3 (SLIDE). The automatic mine operator who controls the movements of the mine scraper had the heaviest average exposure (5.8 mg/m^). The machinery in these mines was diesel-powered and the amount of diesel fume in the respirable mass fraction was not determined. Table *1 presents the average respirable mass concentrations of the millers according to job and company. The highest dust exposures in all the plants are seen by the dr;/ mill'- operators. BON-01531 V utility men, and crushers in the mill area, and by the baggers and pallc-tizoro in the shipping area. The. small sized operation at Company A is reflected by the limited number of samples. Most' of these millers rotate jobs depending on the production cycle and therefore their exposures are in the miscellaneous category. Company B has the highest' dust concentrations v/ith major contributions by the dry mill operator and utility man who works the night shift in the mill area. The age of this milling equipment and may have added to their dust exposures. * : In the shipping area of Company B, the respirable mass'filters of the three-man team were changed at mid-day to assess the actual dust load from the bagging and palletizing operations. Dust ex posures in.the shipping areas of'Company-B were found to te-dependent on the work habits of the men and the grade and particle size of the talc being bagged. The palletizers1 exposure (2.7 mg/n^) may be explained by the manual handling and tossing of the 50 pound dusty bags onto the pallets and the lack of any local exhaus I ventilation at transfer points. These bags may have had an ineffi seal which may have caused leakages and dust exposures to the palletizers. The lower dust levels of the baggers and palletizers at Company C may be attributed to a better seal of the bag? and a more efficient ventilation system. BON-01532 \* v Quartz Analysis , Seventy percent of the respirable mass samples from each company v/ere randomly selected and analyzed for free silica. Fifty percent were analyzed by infrared spectrophotometry and 102 by x-ray diffraction.performed at Harvard and 102 by x-ray diffraction performed at NIOSH... The limit of detection by infrared spectrophotometry is 5 yg SiOg and by x-ray diffrac tion is 10 yg (HSPH) and 20 yg (NIOSH) Less than ten percent of the filters examined had measurable quartz concentrations and these jobs and exposures are listed in Table 5 (SLIDE). All quartz exposures were belcv; the present O threshold limit value (TLV) of 100 yg/m . xn the underground mine at Company C a maintenance-worker had a considerable ex posure (63*6 yg/m^). During the winter survey a driller experienced 9^-7 and 70.2 yg/m^ quartz on two days. On both occasions he was doing, some drilling in an uncharted area and may have found a quartz vein. The ore from this underground, mine is processed at Mil`1 #1, and free silica was found in only ono of the eighteen respirable mass samples analyzed from this plant. Table 5 shows that a palletizer received a quartz exposure of 92.3 yg/m . In the summer survey the automatic miner operator at the open pit was exposed to 26.0 yg/m free silica. This oro was brought to Mill #2 and a maintenance/baggerman received a 3 respirable quartz dose of h1.8 yg/m . BON -01533 V Fiber Counts The carcinogenic potential and the hazards of asbestos exposures have been well documented. Also, several types of asbestos are known to be geological contaminants in talc ore. Since the accepted best index of exposure to asbestos requires counting the respirable fibers in the worker's breathing zone, the problem arises in the methodology of distinguishing asbestos fibers from talc. Characteristically, talc has a ten dency to curl and stand on its edge which may result in many erroneous counts (SLIDE). The latest USPHS/NIOSH method for counting asbestos fibers requires phase contrast microscopy at 400-500 X and thus arbitrarily' defines a fiber as a particulate with a length to width ratio of 3:1 or greater, and a maximum width and minimum length of 5 micrometers. This method is a crude determination of total fiber exposure because of the resolution limitations of optical microscopy. {-lost airborne asbestos fibers are less than 5 ym in length and those that are longer may have diameters too small to be detected by phase contrast microscopy. To compensate for the many controversies our sampling protocol Involved taking parallel fiber samples on Killipore (0.8 ym) and Nuclepore (0.4 ym) filters and quantitating the BON-01534 fibers by phase contrast microscopy and Scanning Electron Micro- 'i scopy. The fiber samplers were placed in the immediate vicinity of the worker and a breathing zone sample v;as obtained without having the man wear the pumps. The Millipore filters were counted using the latest USPHS/NIOSH method at ^37 x magnification The evaluation of the corresponding Kuclepore filter by Scanning Electron Microscopy at 5000 X allows one to morpholo gically distinguish rolled talc particles and talc shard from actual fibers; Fibers less than five micrometers in length may be counted by the higher magnification of this instrument, and the sample stage may be rotated to view a specific particle*at . various angles. The following series of slides are scanning electron micro graphs of some of Nuclepore filter samples. 1.' Counting field at 400 X which is the magnification recommended for fiber counting by phase contrast microscopy. Notice the number of elongated particles that fit the defini tion of a fiber. 2. However, at7000' X this elongated particle is morpho logically not a fiber. 3. One rolled talc particle at 12000 X which has curled on both sides to form a tube. At a lower magnification this particle would be counted as a fiber.. 4. This is an elongated particle standing on edge at 3500' X which might be considered a fiber. 5. However, by rotating the sample stage 60, one can see the laminated .features of this talc particle. BON - 01535 V G-7. Even come "fibers"( tiro riot immune from closer scrutinization. When this cample stage is rotated 5-0, this so-called .fiber" now has this appearance. These magnifications are 5000 X and 15000 X respectively. Table 6 represents a partial list of fiber samples and shows that by phase contrast microscopy the counts range from 0 to 60 fibers/cc. The parallel filters counted by SEE are greatly reduced and range from 0 to 1.0 fiber/cc. These concentrations are below the present TV/A of. asbestos which is 2 fibers/cc greater' than five micrometers in length based on the phase contrast method. If the minimum length restriction is released, then the total fiber concentration for some of these samples' changes slightly and ranges from 0 to 2.0 fibers/cc. Thus, this SEM method provides a more realistic approach to fiber counting in -he talc industry. To further correlate these data, half-filter samples of the % heaviest fiber samples by phase contrast microscopy were sent to NIOSH for analytical transmission electron microscopy. The samples were prepared by using heavy carbon coating which allows analysis by electron diffraction and microprobe techniques. Each of the samples contained elongated particles meeting the definition of a fiber (3 To 1 aspect ratio). However, most elongated particles were identified as talc based on their selected area electron diffraction patterns. Several of these particles were identified as antigorite. No asbestos fibers were seen in any of the other samples. BON -01536 Conclusions 'a/ The Vermont talc industry was selected by NIOSH for both epidemiological and environmental surveys to establish a TWA dust exposure because this talc was believed to contain' minimum amounts of quartz and asbestos. This environmental study characterized bulk samples from the three companies and quanti tated the talc workers' dust exposures. X-ray diffraction i studies showed that the bulk samples contained major amounts of talc, and only trace amounts of quartz were found in 15% of these samples. Petrographic microscopy analyses, analytical transmission electron microscopy, and x-ray diffraction 'with" step-scanning revealed no asbestos in the bulk samples. Respirable mass sampling provides a more realistic method to determine personal dust,exposures than midget impinger sample In addition,., the amount of respirable quartz in the respirable dust sample may be determined by .infrared spectrophotometry or x-ray diffraction. Thus, the overall picture of the quartz and dust concentrations to which the v/orkers are exposed may be obtained with reasonable confidence. The study further showed that scanning electron microscopy should be considered as an adjunct to the lilOSH/USPHS method when counting fibers In a dust environment. Phase contrast microscopy may suffice in an asbestos envibonment, but the resolution limitations of optical microscopy and the inability to distinguish rolled talc particles and talc "shards" from actual asbestos fibers will allow only a crude determinatio of the total fiber exposure. BON -01537 a/ Some Chemical and Physical Properties of Talc Talc 3Hg(MSi02'H20 Refractive indices; 1.54 - 1.6 Specific Gravity; 2.6 1 2.8 Hardness (Mohs scale): 1 Color: White or Gray to Apple Green Morphological varieties; Laminated and Fibrous BON-01538 'a/ Some Minerals Found in Industrial Talc Chlorite Magnesite (MgFe)5 Al(AlSi3) 010(0H) MgC03 Dolomite Calcite Ca Mg(C03)2 CaC03 Serpentine McgCSi/jO^g) (OH) g Quartz Si02 i Tremolite Ca2 Mg3 Sig022(OH)2 BON - 01539 u TABLE 1 QUALITATIVE ANALYSIS OF BULK SAMPLES BY X-RAY DIFFRACTION SOURCE MAJOR .(20-100%) MINOR (5-20%) > TRACE (<5%) Mine (37) Talc Magnesite Hill (20) . Talc Magnesite ) Chlorite (Dolomite) Chlorite (Dolomite) Dolomije . Calcite Quartz Biotite Ankerite Chromite Phlogopits Oligoclase Calcite Quartz Phlogopite Biotite Dolomite BON -01540