Document YroyNk33BkOYe8qBNZrno1NvK

INDUSTRIAL HYGIENE SURVEY i ( Construction Insulation Shop - Building 511-2018 Report R3-IH-3-G-1 Simjfr: Tne Construction Insulation Shop (Building 2018), Plant 512 location, routinely fabricates large quantities of insulation block with ventilated band saws. Tids more efficient procedure of fabrication has replaced an older, tin honored, practice of using simple handsaws to do the job. However, it has, at the sane time, created a health hazard resulting from exposure to eecessive concentrations of atmospheric dust. The hazard to health has been evaluated and reported previously* with the result that one material, "Thermobestos" wes clearly identified with the hazard (exceeded TLV) and another material, "Kaylo", wes safe to fabricate (within TLV), The present report (the third on this subject) was initiated in an attempt to supply answers to three basic questions: (1) wes there any error in the original evaluation of "Kaylo", (2) can supplementary exhaust ventilation reduce the "Thermobestos" hazard to within safe acceptable limits, and (3) is a hazard to health produced in the fabrication of e third mterial, i.e., "CareyTemp". The information uncovered in the present evaluation reveals the following facts: 1. "Kaylo" insulation blocks can be safely fabricated with the . existing equipment, ~ 2, "Thermobestos" insulation blocks cannot be safely fabricated at the present time with existing equipment, but could be safely fabricated if the exhaust ventilation is improved. 3. The TLV (Threshold Limit Value) for "Carey-Terap" is identical with that established for both "Kaylo" and "Thermobestos", i.e,, 20 nppcf (million particles per cubic foot) of air. 4, "Carey-Teop" also cannot be safely fabricated with the existing equipment, but could be if improvements are made in the ventilation system, 5. The original "downdraft" exhttust ventilation rates, on either band saw, do not meet the reccranended capture velocity rate of 4,000 fpm (feet per minute), . 6, The supplementary "overhead" exhaust ventilation on both bana saws, is an improvement and the rates do meet the reccnrended capture velocity rate of 4,000 fpnu I.H. Reports 62-IH-l-G-l`anfl 62-IK-2-G-I 2. TEOSUCTION: A report, submitted in March 1962, stated that an inhalation hazard to i Health was produced in the Construction Insulation Shop whenever "Thereobestos" insulation blocks were fabricated. In July 1962, a seeM swvey was conducted in order to evaluate three new "Thenaobestos" materials which had been supplied by the manufacturer for evaluation# This survey revealed that, although tte inhalation hazard to health had been substantially reduced from that encountered during the first survey, the atmospheric dust concentrations being mitred during fabrication of these new products, were still in excess of the Threshold Lijiut Values as designated in the first report# Therefore, all reocaan^ations should remain exactly as stated in the initial report of March 1962# The manufacturer and Uhion Carbide's Purdmsing Department expresses a great deal of concern about the findings revealed in this initial report wten ' it was uncovered that the manufacturer's Research DeperOHRC also had evaluated these materials and was not able to produce results with those contained in the report of I-Sareh 1962. That is to say, the attnospheric dust concentrations reported by the manufacturer, tfcen processing 'Thermobestos" insulation blocks, were substantially hitter then those revealed in Report 62-IH-l-G-l# This revelation disclosed the need for s more extensive evaluation of this problem so as to resolve all differences of opinion relative to the atasspharic dust exposures in this environment# This decision in favor of further evaluation, promoted the production of a such sore extensive study than was originally planned, a study which eventually enoompassed three separate intervals of dust sampling, analysis, ( and cvalution before all of the unanswered health problems could be resolved. ^ 3CUSS1QN: These three investigations were actually initiated for the general purposes of both clarification and identification purposely for clarification of the actual tezard to health (if any) connected with the fabrication of three different insulation uterials and identification of acceptable measures for use in reducing all exposures to within safe acceptable limits# However, each investigation occurred for clearly identifiable reasons as explained below: The investigation of 24 Jan 63 was contacted because: 1# The Johns Manville Company submitted a report, oompiled by the Research Department, vfiich contained data that conflicted with that submitted by this department in Report 62-XH-l-G-l# 2# This department desired to clarify the reasons for the discrepancy between the two reports and to identify positively the actual coalitions as thsy exist in the working environment The investigation of 2$ and 26 Feb $3 was contacted because: 1 In the preceding investigation, the two insulation materials in question, i.e., "Thermobestos" and "Xaylo" were evaluated inadvertently during the same afternoon, a procedure which. was not in keeping with an attest to stimulate the condition: of the original report. In the original report, each materia. was evaluated on separate occasions so as to preclude the possibi-.it/ that any one sanple might contain dust produced by bet- . -irations# 2. The "Kaylo" insulation material had to be re-evaluated. 3. The Construction Insulation Shop requested that a new insularior. material,-i.e., "Carey-Temp", be evaluated* The investigation of 6 har 1963 was conducted because 1. The Construction Insulation Shop recently had installed supplementary exhaust ventilation on both hand saws and desired to know if this additional control method would reduce the "Thermobestos" dust conceptions to within safe acceptable limits. A oonparison of the reasons listed above discloses ttet each was different in content and concerned actually with different investigations but all were interrelated in part, i.e., each was concerned with the same environment, the same location and the same specific methods of fabrication. Consequently, the sampling procedures, utilized in each instance, basically were identical and in accordance with the following condensed explanation: First: Two methods of fabrication, .i.e., cutting and edging, and cutting a radius, were evaluated at each band saw since this is standard practice, followed in the fabrication of any insulation material. Second: The environmental conditions of both preceding reports, i.e., 62-IH-l-G-l and 62-IH-2-G-1, were duplicated in that ' all outside-.(tears to the building were closed. Third: Each dust sample was oollected in the operator's breathing . zone as he. worked in the fabrication process. Fourth: The complete fabrication of "Carey-Temp" insulation blocks was evaluated in two ways: First, with all available ventilation in operation and second,with only the -original downdraft ventilation in operation. Specialized sampling procedures were utilized also during portions of the latter two investigations, in an sndeavor to evaluate the supplementary exhaust ventilation system which had been installed as recommended. These were as follows: First: ' The complete fabrication of "Thernobestos" insulation hloo was evaluated in two ways: First, with all available ventilation in operation and second ,with only the original downdraft ventilation in operation. Second: The complete fabrication of "Carey-Ten^" insulation block was evaluated while utilizing all available exhaust ventilation. It is necessary to explain that "Kaylo" insulation blocks were not included as a part of this evaluation since the initial investigation, (performed without supplementary exhaust ventilation) disclosed only one exposure exceeding the TLV of 20 nppef of air and, therefore, it could be assumed that an/ ventiUtio; that might be added should he more than adequate in controlling the hsaari, EVALUATIONS: A. Atmospheric dust exposures: 1. The concentrations of inhalable dust, present in the breathing zone when fabricating any one of the three types of insulation materials, were determined in accordance with the following procedure: a. Three locations and nine different conditions of exposure, as described on Page 9, were selected for evaluation* b. Atmospheric dust samples were collected through the use of the impingement* principle of air sampling. The midget impinger apparatus (described on Page S ) served as the instnnent of use. c. The concentration of dust collected in each sample was established through the use of standard' light field microscopic counting techniques as described on Page S ' 2. `The size of the particles of inhaled dust was determined, for both "Kaylo and 11henBDbestosn, in tha initial survey of 1962 in accordance with the procedure described on Page S Consequently, no effort was expended to repeat the determination far any of tha insulation materials since the ' sawing techniques as well as equipmant, i.e, saw blades with three teeth to the inch operating at 2200 linear feet per minute, were identical on both occasions and, therefore, the siae of the particles should not be expected to deviate to any great degree fran the prior recorded values. 3. The composition of the dust, i.eM percentage crystalline free silica or percentage asbestos was determined for both "Kaylo" and "Thenaobestos" in tha initial survey of 1962. Consequently, no effort was expended to repaat this determination sinca the materials used on both occasions, wer> reported as being identical in composition. However, since the ccmpositi of "Carey-Tan^" was not established at any earlier date it was deemed imperative that it be detennined and repoztad at this time. This was accomplished as described on Page S. B. Local exhaust ventilation controls: 1. The velocity of the air being exhausted through the ventilation hoed openings on both band saws (fl and 92) was maasured through the use of a Model 60 Anemothero air aster. 2. Four variable conditions of interest ware evaluated; a. The velocity of air through tha dowidraft hood on both saws with all other hoods cn the Bystem closed off. * This means to strike against, as (ir. :-_is application) the striking'dr dashing of atrosphe dust particles against the bottert j: s-ail impinger flask containing a specific vo-ne of dust-free water as a collect i.\g 5. b. The velocity of Air through the doundraft hood on both saws with All other hoods on the system open. c. The velocity of ear through the supplementary overheac hood on both sews vith all other hoods on the system closed, off. d. The velocity of air through the supplementary overhead tood on both saws with all other hoods or. trt system open. PROCEDURES: Both sampling and analytical methods were as follows: SAtffLXNG: 1. All samples used ir. determining the actual concentrations in air were collected with a midget iflpinger apparatus* sapling 0.1 cubic feet of air per minute through impinger flasks containing IS milliliters of double distilled dust-free water. 2. All samples used in obtaining particle sise distribution data were collected on millipore filters connected to a soil battery-operated pump. ANALYTICAL: 1. Each dust sample was evaluated through the use of a counting procedure referred to as the light field microscopic counting technique.* ( 2. The particle sizing techniques were derived from two separate sources. First* the sample was prepared for sizing in accordance with a permanent mounting method.^ Second, the actual sizing was accomplished in . accordance with the reocranended technique depicting the use of a filar micrometer and a standard microscope while using both the 43X (high and dry) and the 97X (oil iasersion) objectives. 1 3. The.evaluation and free silita determination of "Carey-Temp" material was accomplished through the use of two methods. First, through information supplied by Mr. E. D. Dnaanc, Director of Research of the Fhilip Carey Manufacturing Company and second* through contracted analysis performed by Mr. Thaos M. Durkan, Chief Chemist for the Trudeau Foundation* Inc., Saranak Lake, H. Y. RESULTS: See Pages 8, 9, 10 art 11. * Drinker art Hatch: "Industrial Dust", 2rt Edition, pp. 1S2-1S3, McQraw-Hill Book Company, Inc. $ Hew York, 1954. Pautus, H. J., Talvitie, N. A., Fraser, D. A., and Keenan, R. 6.: "Use of Mmbrane Filter in Air Stapling". A.I.H.A. Quarterly. Vol. 18. o 269. September, 19S7. t rinker art Hatch: "Industrial Dust", 2nd Edition, pp. 166-179, Motoaw-Hill Book Company, / Inc., New York, 1954. - CONCLUSIONS: 6. Relative to dust exposures from Qfltph. fl Tables on Pages 8 9: 1. "Theraobestos" insulation blocks should not be fabricated wher using o;d> the original dowvdraft exhaust ventilation. 2. "Kaylo" insulation blocks oould be fabricated safely when using only rhe original downdraft extaist ventilation if existing leeks, observed on vhe #1 band saw, are connected. 3. "Kaylo" insulation blocks definitely smy be safely fabricated when using the entire extaust ventilation facilities now available, i.e., hoods above the blocks as well as below. From Graph 12 S Tables on Pages 8 ( 9; 1. Methods of handling "Thenaobestoe" blocks (preparatory to sawing) and screps (after sawing) contribute greatly to specific individual exposures as demonstrated by the following facts: a. The fabrication process, vfuLeh always begins at tha #2 band saw with tha simple cutting of each 18" x 38" x 4" block into three mailer blocks about 18" x 12" x 4", is normally the least dusty of all the fabrication operations as revealed by the ssnples taken on 24 Jan 19 b. However, on 6 Mar 1963, this operation was revealed as being one of the dustiest, regardless of the ventilation being used. c. There was only one major variable between tha samples taken on the two dates, i.e., the method of handling the blocks preparatory to sawing. Consideration of the procedure used on t;.4se dates reveals: (1) that on 24 Jan 1983, tha blocks were rolled up to the saw after taring been removed from their shipping cartons and stacked on a "dolly" for easy individual removal and (2) on 6 Mar 1963, the block ware not removed from their shining cartons until needed by the worker. A large amouit of dust is produced when blocks are renoved individually from the cartone as a result of the natural abrasion produced when one block is pulled over the surface of the other. Consequently, the dust concentrations on this date at this location were greater ttan normal. 2. The supplementary overhead ventilation (added since the time of the preceding two reports) does successfully reduce the dust exposures. However, it does not reduce "Thsrmobestos" dust exposures to within safe acceptable limits wnen cutting radii. FTcm Graph #3 6 Table on Page 9: 1. "Carey-Temp" dust concentrations for each exposure was substantially greater than the cccpanhle "Therwobestos" dust concentrations and in excess of even the most lenient TLV established for Jisaan exposures, i.e SO mppcf of air. ' . i ' 7. 2. The existing exhaust ventilation system as installed on both band saws is incapable of reducing the dust hazard, associated with the fabrication of "Carey-Temp", to within safe acceptable limits, i.e., 20 mppcf of air. Relative to the exhaust ventilation system: 1. The duct velocity in the downdraft ventilation system on both tend saws is far below the reccnmended value of 4000 fpnu 2. The duct velocity in the overhead ventilation systen on both band saws is equal to or more than the recoemendad value of 4000 fpm. 3. The velocity in the dovmdr&ft ventilation systems for both band saws could be increased by patching all holes, leaks, etc., now in existence. 1 HECOWEHMIICNS: 1. Do not fabricate 18" x 36" x 4" "Carey-Temp" or "Thenaobestos" insulatior materials unless: a. The atmospheric dust problem can be reduced to bale* 20 mppcf of aix through the use of improved ventilation techniques or repairs to the existing system, or b. The manufacturers of the two nrnku of insulation materials are able to produce a product which will not release, upon fabrication with < ( band saw, dust concentrations in excess of 20 mppcf of air. L' , Submitted REP:hi 23 October 1963 US3USTR1AL HYGIINE SURVEY Evaluation of Atmospheric Dust Cowiitions at the Construction Insulation S>eo Table II v Atnosp>rie Dust Concantraticn Data Collected Whan Using Only Partial Ventilation, i.e., Only Below tha Blocks Cutting % Edging Insulation Blocks V. Cutting a Radius on Insulation Blocks c Date 6 Mar'63 26 Feb 63 6 Mar 63 26 Feb 63 Table 62 Attnospheric ftist Concentration Data Collectad When Using All Available Ventilation, i.e., Both Above Below the Blocks 9. Cutting t Edging Insulation Blocks Type of Material Theraobestos Carey-Tenp Theraobestos Carey-Teap Description of Llo* cation 61a, i.fte.. . S* otui th Sidme. onf thae 1a2 Band Saaw 12a, i.e., South Side of the 11 Band Saw 12a, ** " ' a a a a a Concentrate in mppef 30.20 51.70 17.59 68.20 Cutting a Radius on Insulation Blocks j Date V 6 Mar 63 6 Mar 63 26 Fab 63 26 Fab 63 \ Type of Material Theraobestos Theraobestos Carey-Teap Carey-Teap Description of Incation , 13a, i.e.. South Side of the 12 Band Saw 14a, i.e., South Side of the 11 Band Saw It NUfttKH 15a, i.e., North Side of the 61 Band Saw Concentrat: in mppcf 22.42 SI.70 85.40 100.90 Index for &aphs #1, 12. t #2 II * South Side 12 Band Saw - Cutting Blocks - Ventilation Only Below 62 * N " 11 M " - Edging " - H m if 63. * ft 12 ff " - Cutting a Radius n it n 14 M " 61 ff m _ n n n n it n 61a * N 12 ff " - Cutting Blocks - n Both Above S Below 12a * If " 11 ff " - Edging * - ft n H t m 63a * M 64a ff " 12 ft " - Catting a Radius " 11 ff it _ n m ft ft ff ft it if n n ft n it ISa North Side 61 Band Saw - Cutting a Radius Ventilation Both Above t Below i t Trial 1 1 2 3 Table 13 Determination of Percentage Crystalline free Silica Present in "T>*2inobestos", "Kaylo" "Carey-Tan?" at Quartz by the '*Talvitie" Method 10. "Therrobestos*1 (As Contained in Report 62-XH-l-G-i) Wi in Grams W2 in Qrns W3 in Grans % free S1O2 0,5002 0.5000 0.5002 0.0390 0.0347 0.0396 0.0069 0.0061 0.0062 6.42 5.56 6.26 Average Percentage Crystalline free S1O2 * 6.4 1 > frial * '1 2 3 "Kaylo" (As Contained in Report 62-EJ-l-G-l) in Grams Wj in Grams W3 in &aas % free S^Oj 0.5000 0.5000 0.5000 0.0807 0.0730 0.0563 0.0433 0.0364 0.0190 7.48 7.32 7.46 Average Percentage Crystalline free S1O2 * 7.4 "Carty-Teap" (As Reported by M*. Thones M. Durkin) 4 October 1963 . Cnepcnents Soluble in Ed Other exponents Soluble in Phosphoric Acid Pvcentege Crystalline Free Sjp2 as Quartz 10.8% 88.89 99.6% 00.4% Tabl* 14 Ventilation Rates on Two Band Saws U. { Date Hood Being Band Saw Cheeked Description of Condition Ventilation Sat. in fpm 25 Feb 63 6 Har 63 25 Feb 63 6 Mar 63 ; 26 Feb 63 6 Mir 63 2S Feb 63 : Mr 63 26 Feb 63 * 6 mr 63 12 12 12 #2 12 #2 12 12 12 #2 Dowdraft M R -m it Overhead n n it Only Damdraft System in Operation N It SUN Downdraft t 6 Overhead tt System m in m Operation Every Hood in the System Open it n n tt tt tt Downdraft Overhead System in Operation II R R aN M Every Hood in the System Open n tt tt tt tt it 1500 1450 1200 1200 950 900 6500 4800 4000 26 Feb 63 f ter 63 Y feb 63 Mir 63 26 Feb 63 6 Hnr 63 25 Feb 63 6 Mir 63 25 Feb 63 6 Mar 63 1 IX IX IX IX n IX IX IX IX Downdraft it . t H It If Overhaul 'N It It ' Only Dovndraft System in Operation It It Ri Downdraft 6 Overhead System in Operation It It tt tt ** R Every Hood in the Systma Open it nits it it . Dovndreft 6 Overhead Systma in Operation It tt N ft tt tt Every Hood in the System Open R R tt It tt R 2100 1500 1600 1150 1100 $500 4500 4200 \ e DUST EXPOSURES WHILE FABRICATING KAYLO & THERMOBESTOS INSULATION BIOCKS WITH ONLY DOWNDRAFT VENTILATIC Concentz^tiorai in nppcf of Air Concentration in nppcf of Air os s S * * X I I k Concentration in nppcf of Air i9 9 9 t8