Document 67DONkaqXamrOxKBv3jXdbXm

SUPPLEMENTAL INFORMATION FOR TESTIMONY CONCERNING POSSIBLE CHANGES IN THE HEALTH AND SAFETY CODE SECTION 25910 AS PERMITTED BY SB-1591 Asbestos Fiber Exposure During The Destruction of Maintenance Coatings By Sandblasting Prepared for the Occupational Safety and Health Standards Board Sacramento, California November 15, 1978 Prepared By Union Carbide Corporation Metals Division Niagara Falls, New York b\ \j PLAINTIFFS I| EXHIBIT i UC-1537 SUMMARY AND CONCLUSIONS The air monitoring test during sandblasting at Corona, California that was reported in the October 30, 1978 DOSHA letter to the Standards Board was a cooperative study.wherein Union Carbide Corporation and DOSHA collected simultaneous paired samples on the workers. A report of the Union Carbide results is provided herein. The UCC counts ranged from about the same to about one-half of those found by DOSHA. Considering the nature of the samples, both laboratories were in accord that the differences were due to the normal random errors in the sample collection and counting procedure and did not represent a significant difference between the laboratories. The critical problem with these samples was the presence of large amounts of mineral particulate that met the criteria for a countable fiber, but in all probability were only very rarely asbestos. An examination of three of the filters by scanning electron microscopy was carried out by Union Carbide. This study confirmed that free asbestos was rare and made up very roughly one countable fiber out of fourteen. This information led to a further cooperative, large-scale sandblasting test at Trona, California wherein the samples were collected by DOSHA and counted by the Federal OSHA Compliance Laboratory in Salt Lake City. The Federal laboratory has considerable experience with this type of difficult sample and uses a combination of sophisticated optical techniques and electron microsopy to aid in the identification of non-asbestos particulate. The results of this study showed a ceiling concentration of 1.6 fiber/cc >5u and 8-hour TWAs in the 0.1 to 0.4 fiber/cc >5y range. We believe that these levels, which may still be conservative (high), are more representative of asbestos fiber release from maintenance coatings during sandblasting than the data that either participating laboratory obtained at the earlier test at Corona. TABLE OF CONTENTS Section___________________________________________ A. BACKGROUND........................................................................................................ 1 B. RESULTS AND DISCUSSION 1. Fiber Counts by the Optical Phase - Contrast Method . . . 1 2. Fiber Analysis by Scanning Electron Microscopy..................... 2 C. COMMERCIAL SANDBLASTING TEST...................................................................4 D. CONCLUSIONS.............................................................. ..................................... 6 E. FIGURES 1-12....................................................................................... . 7 F. ATTACHMENT I 1. DOSHA letter of October 30, 1978 to the Occupational Safety and Health Standards Board. . . , ig 2. Appendix B of October 30, 1978 DOSHA Letter (Village Grove Park, Corona, California Test) ..................... 21 3. Appendix C of October 30, 1978 DOSHA letter (Kerr-McGee Test, Trona, California)..........................................25 G. ATTACHMENT II (Union Carbide Report of Cooperative Air Monitoring Test at Village Grove Park, Corona, California ................. 32 H. ATTACHMENT III (Protocol of Cooperative Air Monitoring Test at Kerr-McGee, Trona, California).................................................. 38 Page i\ 1 A. BACKGROUND during the hearings on the 1976 Presley Bill, Assemblyman Fenton asked the Department of Health to collect additional exposure data during the use of the products for which temporary exemptions were eventually granted. A cooperative government-industry effort ensued. The data obtained were submitted to the Standards Board by Mr. James H. Heacock of DOSHA in a letter dated October 30, 1978 (Attachment I). Appendix A of this letter covered tests of Portland cement plaster. Appendices B and C related to sandblasting of maintenance coatings. This discussion is limited to maintenance coatings, the plaster applications will not be covered. The initial two sandblasting tests (Location 1 and Location 2, Appendix B in the DOSHA letter) involved the removal of an asbestos-containing coating from a plaster or a stucco wall. When the results became available, they were higher than anticipated, i.'e. 0.5-3 fibers per cc longer than 5y. The manu facturer of the paints then asked Union Carbide to participate in a third test jointly with the DOH. This was acceptable to the DOH and the Village Grove Park location in Corona was selected as the site. In this test the blasting operator, helper, and observer each wore two pumps and simultaneous samples were collected in the breathing zone with filter cassettes positioned on opposite shoulders. Paired background" and area samples were also collected. A detailed report of the Union Carbide results is provided in Attachment II. For easy reference the corresponding DOSHA report has also been included in Attachment I as Appendix B. Only the key points of these reports will be summarized here. B. RESULTS AMD DISCUSSION 1. Fiber Counts by the Optical Phase - Contrast Method The samples collected in the test at Village Grove Park, Corona were extremely difficult to count. They were heavily loaded with both fibrous and non-fibrous dust. Considerable particulates were present that met the dimensional criteria of a fiber, i.e. length greater than 5y, length to diameter ratio greater than three, but they were clearly not asbestos. Both counters were experienced and discussed the problem of evaluating filters of this type prior to counting. In an attempt to assess the impact of the asbestos fiber recognition problem. Union Carbide divided the fibers counted into two classes, "obvious chrysotile asbestos" and "possible asbestos fiber." When there was any doubt about a fiber's identity it was included in the count. The total of both classes would be the value ordinarily reported as asbestos. Particles which were obviously not asbestos were not counted. This included such things as unbroken fiberglass, mineral flakes with non-parallel sides, and particulate that appeared bright under phase contrast. It should be noted that the only known source of asbestos of any type was the 5% by weight chrysotile that was added by the manufacturer. (Note that the 2% asbestos figure reported by DOSHA in Appendix B is in error.) i-\ -1- The Union Carbide results ranged from 0 to 0.8 fibers/cc >5u of "obvious chrysotile" and from 0 to 3.6 fiber/cc >5y for total asbestos. (See Attachment II.) These total values are compared- with the DOSHA results for each paired sample collected on the opposite shoulder of the wcrkers in Table 1. These values range from 0.1 to 7.1 fiber/cc >5y. Examination of Table I shows that the pretest controls and several of the samples collected on the observer and on the helper resulted in the detection of only several fibers in the hundred fields examined under the microscope. Blank filters, i.e. those which have never been exposed, will read from zero to several fibers per 100 fields, so these results really are not distinguishable from background. The remaining eight pairs ranged from about the same to a Cal/OSHA counting of about double that of UCC, 7.1 vs 3.2. Considering that these counts are not from the same filter but from filters that were collected on opposite shoulders, both laboratories were in agreement that the differences were probably the result of random errors in the sampling and counting method and did not represent a significant difference between the laboratories. The time-weighted averages for the two operators for the time period where sandblasting was actively.in progress and for the entire eight-hour day were calculated for each set of total asbestos count data and are listed below. The two workers' actual TWA exposures for the particular day were all below 0.5 fiber/cc >5y. The highest value reported by either laboratory, 7.1 fiber/cc >5y is still below the ceiling limit of 10 fiber/cc >5y. Time-Weighted Average Exposures (Fibers/cc >5y) During Active Operations Cal/OSHA UCC 8-Hour Day Basis 'Cal/OSHA UCC Helper 1.1 0.6 0.2 0.1 Operator 4.1 2.2 0.2 0.2 2. Fiber Analysis by Scanning Electron Microscopy It was evident from the results that non-asbestos material was being included as asbestos in the counts reported. In order to check this further. Union Carbide examined three of the filters with a scanning electron micro scope. A small square from each of three filters was exposed to acetone vapor under conditions that had previously been determined to collapse the filter to a smooth surface but did not allow the particles to sink into the filter. Shrinkage in area was measured and found to be about 45%. The samples were then gold-coated and mounted for microscopic examination in the normal manner. -2- 1 TABLE I COMPARISON OF AIRBORNE ASBESTOS FIBER COUNTS DURING SANDBLASTING OF ASBESTOS CONTAINING MAINTENANCE COATING Description of Ooeratlon Sample Data ime Total Wo. On Off Hin. Pretest Controls On fence, left side of area to be sand-blasted. 41/2* above ground. G-16 10:35 10:56 21 On fence,''100' from G-16. --5' above ground. F-44 10:42 10:59 17 Personal sample on observer '25' from fence and moving parallel to fence. A-66 10:39 10:52 13 Observer (During Sand-Blasting) Personal sample on observer A-81 11:12 11:18 ~20-30' from fence and moving 11:25 11:27 parallel to fence. 6 2 8 Same as A-81. J-89 12:26 12:52 26 Area sample on fence. 5* G-3 above ground and -40' down- wind. (In lieu of observer) 1:35 2:00 25 Helper (During Sard-Blasting) Personal sample. Assisting with hoses. Operating sand feeding equipment. G-48 11:10 11:18 8 11:24 11:26 2 Iff Same as G-48. X-8 12:25 12:48 23 Same as G-48. Same as G-48. C-1S X-4 1:08 1:36 1:22 14 1:58 22 81astinq Ocerator (During Sand-B lasting) Personal sample. Operator handling sand-blasting nozzle, standir.g--2' from fence. 0-71 11:10 11:18 8 11:24 11:26 2 Same as 0-71. X-14 12:25 12:36 11 San as 0-71. 6-34 12:38 12:46 8 Same as 0-71 ercept inside of hood. San as D-71. X-2 1:08 1:22 14 X-3 1:36 1:S3 22 L'CC 130 fields ilSL Cal/OSHA f/cc Fiber Counts Asbestos UCC SEM (f/cc) Non-Asbestos Total Cements 2 0.1 0.3 00 0.1 2 0.1 0.2 1 0.1 0.1 1 0.03 0.2 29 0.7 1.9 15 1.0 1.4 28) 45) i.r 2.2 3 0.2 0.5 2 0.06 0.2 32 2.2 1.6 43) 58) 3.2 7.1 38 3.3 6.6 34 1.7 3.7 56 1.8 2.1 3 Asbestos 0.3 1.0 1.3 fibers in 25 fields - 0.3 1.5 1.8 3 asbestos fibers in 25 fields 0 asbestos 0.0 1.0 1.0 fiber in 75 fields (-, `j 7 3 Random fields were then selected and examined for particulate matter which met the "fiber" criteria, i.e. L >5y, L/D >3. Magnification was 1500X and the defined field area used was 0.0048mm2, This is similar to the optical counts where the field was 0.0062mm2. Whenever a fiber was found it was analyzed by Edex in the spot mode for chemical composition. Detailed results are listed in Table II and Figures 1 through 10, and are summarized below. Sample No. X-3 G-3 D-71 Total Fields Counted 75 25 25 125 Fibers Found^ Chrysotile Non-Asbestos 0 34 3 2(2) 11 19 5 64 Total 34 14 20 69 (1) Length greater than 5p, length/diamer greater than 3/ (2) Does not include a non-fibrous asbestos "clump". These data demonstrate that free asbestos fiber in the generated dust is both rare and a small fraction of the total fibrous particulates, in this case about one fiber in fourteen. The potential for erroneously high counts by the ordinary phase-contrast optical method is obvious. The number of fields examined for each filter and number of fibers found were too small for a reliable estimate of airborne concentration. As a point of interest, however, the fibers per cc values corresponding to the numbers of fibers found have beenshownin Table 1 and positively identified chrysotile asbestos ranged from 0 to 0.4 fiber/cc >5y. These would be ceiling, not TWA values. C. COMMERCIAL SANDBLASTING TEST When these results became aviTable, the problem was discussed with Mr. Heacock of the DOH and it was agreed that a carefully-planned, large-scale test using professional operators and equipment should be made. Samples would be collected by DOSHA and counted by the Federal OSHA Compliance Laboratory in Salt Lake City. This laboratory has had considerable experience with the type of highly contaminated samples expected and utilizes a combination of sophisti cated optical techniques and electron microsocpy to provide more reliable counts. -4- f\ ^ `' TABLE II SAMPLE ANALYSIS BY SCANNING ELECTRON MICROSCOPE 15QOX Chemical Composition by EDEX Field Area 0.0Q48nm Full Ho. 1 2s 4 ft ft ff7tt IQ 11 I1Ut) I1Sft 1U7 a to 21 a a a71 vna 30 31 37 S 34 39 3ft 37 38 3ft 40 41 a42 44 4ft 4ft 47 4ft 9f0t b, of Fiber* Appros. Umu (y) 7.S 24I 1ff0tt I1SS2 10 12 ft TTfttbtfi amt no. i-i Sl2a,A121ISlSlft2iIL 14--tlfleitl-- X I X X X- X XXX X - X - bftitmUl (PhotM 1 1 It) ft-- Albeit-- X I X I I I XIX* X X XXX* X XXX* XXX* XXX* XXX* Bon-Asbestos (Fhotn 2 4 2) loU Hpn*Asbestes loth H---Asbestos (Photos 3 4 1#) lots --'Asbolt-- ill io fanim libest-- ion ham. ft Asbttn Ml it m. m 1 Mcll b. if long-- _nc._ fibn to !ii!SL!2!l.!!aH ideottfiesti-- 1 X X* X bi-Mkntn RoMsbstot ia> Album X bMbbstM t 11 12 13 14 IS 17 19 20 21 22 n 24 a a 27 a a a 31 8 a 34 a a 8 8 8 40 41 a a 44 a 'a 47 a 41 a is XX 2 7 . X 7 X i 1 - -X 0 0 0 ft-- *4*1101 0 0 H-- Athittni 1 a *-X X**--- 0 1 to - - - I bt-bbstM o 0 0 0 0 0 0 0 1 ft - - * X 0 1 n ---X ---Atb--tos bM-AibstM 0 0 0 1 is - - I X X............................. MMbbstoi 0 0 3 IS * * * X ft 14 - * I All bi4ibim 0 f0t 0 2 14 X 14 - X both bi fabutw 0 1 IS - - X Aon <ibwt 9ribn 200 Mta-bbibtiSi tM (1) Iwemlvi idjKNt fteUs tMitai field ftp, 21 43ft ftt 111f90t 12 13 1If4t 1ft 11tf7ftt 20 21 a a 24 a fto. #f Fibers Approx. Length (u) 27 ISSft 10 10 1f0t ft ft 7 ff7tt ytftom Wit WO. 6-1 Hi M SI I ft Cm ft to T1 Id--tlflcstlow X*X***** {_AsSStOS IPhQtOf 14 4 uofl **X******A11 ft---Asbestos ---X-.*--- ::Ji5:::: X*X***** r*i6m I .X* MtfAlMtUI - - X I 1 - - - - on libntw X*XX***** iAsbestos^ 111..... ft-- liWitb XXX***** All Re-Asbnt-- ft JkSbMt-- II ta-Aibitb -5 SOfU NO. 0-71 Holft Ho. of lin;tt bo. Fibers tw) 1 ft 2 2 14 21 X ft a 8 4ft 0 0 7 4 14 14 a a ft i a 1 7 a ft ii ft V ft 13 2 ft s 19 tft 17 fffttt Ift 1ft 1ft a1 f7t <i t 1f4t a1 a a ft a1 H W Fibers Hl!&12iIAa.ItLli Hentlfleitl-- X X X X - H---Asbestos a X1X * ftptk ft--Asbestos mX X I X X X * ftpu ft---Asbestos m m XX 1; I I X All II-- Asbestos m X X X X X 1 Asbestos Photos 5 S ial 1 ft s X X 1 Asbestos Photos ft Sfte) 1 mm sXX XXXX Ho ntM oHUImH (burnout). rifpotto's Photos 7 #d 74; Hot to--tco is Asbestos ftp roedl-- obUlood (bvmpot). XX4 XX XXX X X Hot Co--tee m Asbestos I AthesM'. (phntO* \ri H---Asbestos (Photos ll 4 Hop-Asbestos (Photos 12 4 ft-- Asbestos A. I Aibostot Flbon 1 Asbestos Cl--e 17 ft-- blmtos The protocol for this study is appended as Attachment III and the DOSHA Report (Appendix C of their October 30, 1978 submission to the Board) of the study is also given for reference. The DOSHA report covers the test very well although it should be noted that the Federal GSHA counter included any fiber of doubtful identity as asbestos so the results presented would be conservative (high). It is also appropriate to acknowlege that the test site was provided through the courtesy of Kerr-McGee Company at Trona, California. Figures 11 and 12 show photographs of the test which give a clear illustration of the nature and scope of the operation. D.- CONCLUSIONS The fiber counts reported in Appendix B of the DOSHA letter of October 30, 1978 as well as the Union Carbide counts of the simultaneous counts include a great deal of material that is not asbestos. The subsequent large-scale test although possibly still conservative (high), is more representative of exposure during sandblasting. -6- E. FIGURES 1 - 12 Photo 1 - Sample X-3 @ 10.000X k -7- FIGURE 1 Photo 2 - Sample X-3 @ 1500X 8 FIGURE 2 Photo 3 - Sample X-3 @ 1500X -9- i\ i FIGURE 3 Photo 6 - Sample D-71 @ 1500X Photo 6A - Spot Mode of Particle Shown Above -10- i FIGURE 4 Photo 5 - Sample D71 @ 1500X Photo 5A - Spot Mode of Fiber in Above Photo -11- FIGURE 5 Photo 7A - Spot Mode on Particle Shown in Photos 7 and 8 A ' :n -12 FIGURE 6 f, Photo 10 - Sample D-71 @ 5000X FIGURE 7 Photo 11 - Sample D-71 @ 1500X -14- FIGURE 8 Photo 12A Spot Mode of Fiber Particle Shown Above -15- FIGURE 9 Photo 14 - Sample,G-3 @ 1500X Photo 14A - Spot Mode of Particle Circled Above FIGURE 10 16 COMMERCIAL SANDBLASTING TEST KERR-MC GEE CORPORATION - TRONA, CALIFORNIA !-\ Operators Sandblasting Bottom Portion of Tank -17- FIGURE 11 COMMERCIAL SANDBLASTING TEST KERR-MC GEE CORPORATION - TRONA, CALIFORNIA Operator on Manlift Sandblasting Top Portion of Tank DOSHA Representative Collecting Samples and Recording Data r r tnr 1 O F. ATTACHMENT I 1) October 30, 1978 Letter of Mr. James Heacock, Supervising Industrial Hygiene Engineer, DOSHA to the Occupational Safety and Health Standards Board. 2) Appendix B - October 30, 1978 DOSHA Letter. 3) Appendic C - October 30, 1978 DOSHA Letter. STATE OF CALIFORNIA DEPARTMENT OF INDUSTRIAL RELATIONS DIVISION OF OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION 1449 WEST TEMPLE LOS ANGELES. CA 90034 -9 i; EDMUND O. MOWN JR.. Cor.,ne October 30, 1978 Occupational Safety and Health Standards Beard 1006 Fourth Street Sacramento, CA 95514 *0V 0 1978 1978 ' '* Gentlemen Subject: Public Hearing November 8, 1978 Asbestos Products in Buildings and Structures The Occupational Health Branch of the California Department of Health evaluated employee exposures to asbestos during the destruction of building materials in an industry-government cooperative consultation program. Results of those tests have bearing on all items of the hear ing and specific information on Items 1, 2 and 5. Previously applied sprayed materials containing asbestos were removed by sanding or sandblasting, or the structure demolished. The employees doing the work were sampled and results analyzed in the same manner as any other compliance or consultation QSHA samples would be handled. (In one study, samples were analyzed by the Federal 0SHA Laboratory in Salt Lake City in the hopes that advanced analysis might be available. They repeated the California OSHA Laboratory and NI0SH methods.) Regarding Public Hearing Questions 1 and 2, the report of employee exposures to airborne asbestos during demolition of a portion of an apartment building previously damanged and burned by a light airplane is attached as Appendix A. The stucco was identified as having been sprayed, and as having contained less than one-half of 1 percent asbestos. In summary, employee exposures during demolition were determined to range from 0.25 to 0.83 fibers longer than 5 microns in length per cubic centimeter of air. Regarding Public Hearing Question 3, if any exemptions should be granted by the Board, it is recommended that employee exposures be limited to, and employee protection be the same as, that specified in Title 8, CAC 5208 Asbestos. 19 ! Occupational Safety and Health Standards Board Page 2 October 30, 1978 Question 5. Regarding exemptions for products containing ''encapsulated fibers," tests conducted by the Health Department indicate that*the fibers are not all "encapsulated" during destructive removal, such as sanding or sandblasting, but rather are also found as free fibers. Four studies were conducted, with reports forming Appendices B (consolidated report of three studies) and C. In all studies, employees were exposed to asbestos fibers, with a range of 0.1 to 7.1 fibers/cm3 (greater than S microns in length). Supervising Industrial Hygiene Engineer Jffi/cs enc -20- -/ - `APPENDIX B TEXIUKSD COATrJCS OF AMERICA, EIC. Because of Legislature concern with regard to future worker ezposure to the asbestos contained in asbestos coatings being spray applied, the Occupational Health 5rar.cn conducted industrial hygiene ceterminations of worker exposure to asbestos released from substances (these materials covered by the execstiens introduced by SB 1596), previously applied and aged, during building rsnovaticn/repair and demolition cperaticr.s. Kr. P. Tillisch cf Textured Coatings of America (TCA) agreed to provide appropriate opportunities for such determinations during typical in dustrial cperaticr.s. This study involved intermittent sampling and analytical determinations over a period of several months. On three different occasions, the Department of Health, Occupational Health Branch and TCA conducted tests: (1). August 311 1976 at 1S01 Exposition Blvd., Los Angeles, for building interior coatings (2). November 16, 1976 at 950.S. Broadway, Los Angeles, for building exterior coatings and (3)* December 17, 1976 at Village Grove Park in the city of Corona for exterior fence coatings. `* METHOD At all three locations sanding or sandblasting was used to simulate building renovation. . At the first location, 1501 Exposition Blvd., Lcs Angeles, the tests for asbestos were conducted inside the building at the end of a hallway which had been partitioned off from the rest of the building (to keep dust to a mini The enclosed area was approximately 5 ft wide, 12 ft long and 3 ft high. Inside the partitioned area an "employee" did the actual sanding. The "ecplcy was Scott Tillisch, an employee of TCA. He was observed by Mr. J. He acock and Mr. L. Beck-of the Occupational Health Branch (CH3) and Mr. M. Qrdanik of the Southern California Laboratory Section. The sanding was done with a portable electric hand sender which the operator usea on the wall for approximately 2 hours. Samples were collected zone. (C3Z). The seccr. the sate type of pump three ways. The first was in the operators treathin pe was an area sample, The area sample utilised filter-cassette as the CBZ sample but were located -21- n# H532l/C"2/77! APPENDIX B -2- 2/23/77 on an "observer" who walked back and forth throughout the test area. -The third type of sample.; couleeaor wore "mate-rial" sample:;. These were collected from the sestivi duot after the santing operation cy chipping raaterial off of the sandpaper face, or from the material off of the wail before sanding. At the second 'location, ?50 So. Broodway, Los Angeles, the asbestos test was conducted in the alley behind the building using a commercial sand-, blasting machine. An exterior wall approximately 10 feet long was selected and 'blasted for most of its length to a height of about p feet. Again the three types of samples were collected. Operator Breathing Zone, area, and material sample. A second OEZ sample on the man running the sand mixer for the sandblaster was also collected. The area sample was again collected on an observer walking back and forth through the blasting area, both upwind and downwind of the operation. "Material" samples were from settled sand-dust or from building surface chips. The people involved were Mr. Scott Tillisch as sandblaster (TCA), Mr. Her. Michalak as mixer-hose tender (ISA), Mr. J Heacock (CH3), Mr. L. Beck (CH3) and Mr. M. Crdanik (Sc. Cal. Lab) all as observers. The area samples were collected on Mr. Beck as he observed the operation. The third location, Tillage Grove Park, Corona, utilized the same sandblasting equipment as the second location. This time a fence was sandblasted. The fence surrounded a mobilhcme develooment. 1 armies `ware taken in the vacant lots (#'s 19 end 20) on the Month side of the development approximately 30 feet from the Mcrthwest end of the fence. The two lets were approximately 50* x 1501 combined. Mind cut of the west 3 10 mph. Samples were collected at the sandblasters. C3Z, mixer-hose tender's OEZ and area samples upvrind and downwind, both stationary and mebii. At this third location Mr. H. Rhodes and Mr. B. Ingalls of Union Carbide (New York) represented TCA. as consultants and Industrial Hygienists and collected sarnies along with the Occupational Health Branch. It was mutually agreed that Union Carbide and the Occupational Health Branch would collect samples side by side. People present were Mr. Paul Tillisch, 7.P. of TCA; Scott Tillisch as hesetender-mixer; Ken Schorr as sandblaster; Mr. Pieces and Mr. Ingalls of Union Carbide; and Mr. J. Hinton and Mr. L. Beck of the Occupational Health Branch. Again sandblaster and miner-hes2tender's CHZ's was sampled. Area samples included fined location samples on the fence post upwind and downwind, and roving samples on Mr. Rhodes who walked back and forth threugn the area. Settled dust was again collected as a naterial sazple after the sandblasting ceased. For all three locations sample "Blanks" were kept for analytical comparison. . Laboratory analysis utilised CSKA and KICSH approved methods. a c~x v I \j , /.->J 22 APPENDIX B , --IErr.53Zl/Q22/T& -3- February 23, 1977 Data: LOCATION 1 1S01 Exposition Bf.-fUJ _| Lg3 Angeles Sander- Area Fibers/cc 5 Microns in length 1.7 1.1 0.5 0.3 Both samples simultaneously* within 10 ft of 0.9 it 0.3 * 0.2 na ft ff Material - ifo Chrysotile bound in matrix: Free fibers released with grinding abrasion locatio:: 2 - Latex Base Paint (Vinyl-Acrylic) 950 South Broadway, Los Angeles Sandblaster Mi Hcs - ire a Fibers/cc 5 Microns 1.5 (filter outside of hood) 3.5 " 0.4 * 0.7 1.6 All 3 sarpled simultaneously* 1.2 ff Material - Aldyd Base; 3-555 Chrysotile Asbestos Within 15 to 20 feet of source LOCATIO:! 3 village Grove Park (T.ots 19 and 20), Corona Sandblaster * Mixer-Hcs 0^ ov ............ -- - ---- Fibers/cc * .. - -T.-.- .r-.-.--.*i T*zz~~ . - - - - Before Al\ . *I Up ~i L' ! --J1l Blasting 0.3 (Stationary Backgrc Upwind 0.2 (Moving Background) 0.1 (Stationary Backgrc Unwind* 5 Microns 1.6 (Filter outside of hood) 7.1 6.6 ff ff 3.7 (Filter inside of Hoed) 2.1 (Filter outside of Hood) 1.4 1.2 (Unwind) . * 0.? 0.2 " 0.1 (Moving during bias on ft ft * ff r? n 1.9 (Stationary during bl astir..") Ccvt.-..-;; Material - ** * ctile Within 20 to 10 feet c ^APPENDIX B H# H5321/C22/1TA -4 February 23, 1977 * Horizontal lines distinguish those samples collected in the sane time frame and/or simultaneously. Variables: ALL LCCATIC!~ Several variables were not accour.ted for in the study concerning all three locations. First the sanding modiun was not analyzed for asbestos. At location 1, this would have been the send? zper used and, at locations 2 and 3, the sand used' far sandblasting. Secondly the building material cr. which the texturea coating had been applied v/as not analyzed for asbestos content. At the first location this would have been the wall plaster, the second location, a stucco wall reinforced with wood, and the third location a metal fence. Thirdly, the area samples varied in dietance from the scarce and were not constant with regard to wind direction except in a few instances. Finally, no ''before" and "after" air samples were collects a to establish an ambient asbestos con centraticn, except at the third 1 st ation. Ambient air sarmies at the third location revealed that there is asee stos iron urjcccwn sources cent emanating the air which might be the subject of an environmental study. However, in view of these variables, we feel the results would be changed insignific ar.tly .ad they been acccur. ,sd fcr. Tr.e bag was labeled "ICOfi sand"; the sandblasting went only to the su face of the plaster, stucco and metal; and the chemist ho analyzed the sen les is an experienced expert in the field of asbestos decs manatiens. RESULTS The data.shows that there is a definite exposure to asbestos when employees cr workers sandblast cr sand coatings containing asbestos and that this exposure is present in the immediate area. In this case, the immediate area referred to is within a 10 foot radius of the source in a non-windy condition and with in a 40 foot radius downwind in windy conditions. In any case, at all three locations there was an employee exposure of at least 1 fiber/cc, ar.d up to 4 fiber(zz as an average. The area samples also showed exposure into ahe 1 to 2 fiber/co range. And finally the mixer-hcsezer.der exposure range was from 0.5 to 2.0 fibers/cc. DISCUSS ic: The current standard fcr asbestes is 2 fibers/cc greater than 5 microns in length. However, medical monitoring is required at 1 fiber/cc on an d hr. time wei^ited basis. Since the res; s indicate ezmlo/ss exposure tc 1 fiber/cc and greater, we conclude than .ere is a high possibility of harmful expousres to employees dur renovation. -24 APPENDIX C ASBESTOS SAMPLING DURING COATING DESTRUCTION Many questions have been raised regarding the levels of asbestos fibers released during the removal of paint type coatings containing asbestos. In this investigation, air samples were collected during the destruction of a high performance coating containing 2.1$ asbestos. A 40 foot diameter, 25 foot high steel tank spray coated in 1973 was sandblasted to bare metal. Since sandblasting represents an extreme condition, it provides an estimate of the highest employee or community exposure to asbestos. METHOD Air samples were collected in the breathing zones of workmen using personal sampling equipment. Open face filter cassettes containing 37 mm Millipore AA filters on a cellulose backing pad were attached to the employee's respirator straps or lapel, MSA Model G portable sampling pumps were used to maintain a flow rate of 1.5 liters per minute. Flow rates-were calibrated in the field with a Brooks type 1355-01A1AAA rotameter. Sampling times varied from 5 to 15 minutes. Thirty minute background samples were collected before sandblasting. Unexposed blanks were also submitted. Samples were collected on the three workmen, two sandblasters and one pot tender. Sandblasters wore airline respirators to protect them from silica exposure. ANALYSIS Asbestos sample filter cassettes were sealed in the field, packaged and forwarded to the U. S. Department of Labor, OSHA Laboratory in Salt Lake City for analysis. Samples were analyzed by phase contrast microscopy. Selected samples were also analyzed by dispersion staining and electron microscopy. Results of the laboratory analysis were forwarded as soon as they became available. The optical microscopic results are summarized in Table 1. Asbestos fibers were counted by the standard NIOSH method. Blank sample cassettes submitted with the asbestos samples were counted by optical methods. -25- A .U I APPENDIX C Three unused filter cassettes were submitted. No fibers were detected on two filterst one filter was reported to have 0.01 " fiber/field (100 fields counted). Background samples collected before sandblasting were reported below the detection limits for asbestos. In addition, JK-32, collected during sandblasting of a section of the tank sandblasted to bare metal earlier in the day was also reported as below the detection limit for asbestos. To gain additional information about the fibers present, filters were further analyzed by dispersion staining. In a study of sample JK-3, by dispersion staining, 16 of 110 fibers were identified as chrysotile asbestos Other samples were stained. The fibers present were found similar to JK-3 The nonasbestos fibers were identified as plant fibers and fiber glass. RESULT Time weighted average concentrations were calculated from the optical microscopic analysis. Exposures to the workmen are listed in Table 2. Sandblaster TWA exposures were calculated to be 0.2 and 0.3 fiber/cnr. The pot tender's average was 0.1 fiber/cm^, greater than 5in length. DISCUS" SION o Bnployee exposures were within the present Cal/OSHA standard of 2 fibers/cnr greater than five microns in length. In addition, workers with the greatest asbestos exposure were protected by the airline respirators worn to prevent silica exposure. Sandblaster #1 did not sandblast all day. His calculated time weighted average, 0.2 fibers/an , represents a partial day of sandblasting. Sand blaster #1 was not used between 13:15 and 15:30. Asbestos fiber counts of mixtures of air contaminants containing asbestos are slow and tedious. The standard phase contrast optical microscopic APPENDIX C method was relied upon to determine worker exposures. In this method of analysis, the procedure allows for information gained through additional, testing to be used to more precisely identify countable fibers. The analyst may reject fibers identified as not being asbestos. Dispersion staining and the use of cross polarizing filters, or a first order red retardation plate, give additional information regarding the nature of the fibers. Fibers without the correct morphology or other characteristics, recognized as not asbestos, are not counted. Fibers of doubtful identity are included with the asbestos count. The results of electron microscopic analysis and dispersion staining quantify the proportion of the total fibers which are actually asbestos. These percentages were between 12 and 12$. Although the percentages are small, it is important to note that free asbestos is released. Analysis of blank samples ruled out the possibility of significant contamination from either the blasting sand or desert air. /flw 10/19/78 -27- > " O' O AirJi\mA u Table 1 SAMPLE # OPERATOR TIME ON JK-1 Sandblaster-1 8:21 JK-2 Pot Tender 8:21 JK-3 JK-4 JK-5 JK-6 JK-7 JK-8 Sandblaster-1 8:54 Pot Tender 8:54 Sandblaster-2 9:09 Sandblaster-1 9:14 Sandblaster-2 9:20 Pot Tender 9:26 JK-9 JK-10 JK-11 JX-12 JK-13 JK-14 JK-15 JK-16 JK-17 JK-18 JK-19 JK-20 JK-21 JK-22 JK-23 JK-24 JX-25 Pot Tender 9:46 Blank Sandblaster-2 9:36 Sandblaster-2 9:41 Sandblastei^2 9:47 Sandblaster-2 9:55 Sandblaster-2 9:55 Pot Tender 9:58 Sandblaster-2 10:01 Sandblaster-2 10:07 Sandblaster-2 10:13 Pot Tender 10:20 Sandblaster-2 10:24 Sandblaster-2 10:34 Pot Tender 10:43 Sandblaster-1 10:47 Blank TOTAL TIME (MINUTES) 27 27 4 20 32 11 17 16 20 12 5 6 5 6 12 22 6 7 10 22 10 18 16 16 FIBERS/CC < D.L. <D.L. 0.49 0.35 Membrane marred 0.57 0.31 No membrane in cassette <D.L. None O.63 0.71 1.4 1.6 0.75 0.17 < D.L. 1.3 0.3 0.24 0.32 0.91 1.02 1.27 None COMMENT Background (Desert Air) Sample before sand blasting Background (Desert Air) Sample before sandblasting Under Blasting Hood. Two Sand Blasters working Blasting at ground level On Scaffold Ground Level Two Blasters working Two Blasters working - Ground Level Ground Level Ground Level Ground Level - Overlap JK-2 Hole in filter - Overlap J: Ground Level Blasting of sample 11 minutes break Entire sample break On man lift On ground 28- APPENDIX C Table 1 (Continued) SAMPLE # JK-26 JK-27 JK--28 JK-29 JK-30 JK-31 JK-32 JK-33 JK-34 JK-35 JK-36 JK-37 JK-38 JK-39 JK-40 OPERATOR Sandblaster-2 Sandblaster-1 Pot Tender Sandblaster-1 Sandblaster-2 Pot Tender Sandblaster-2 Sandblaster-2 Sandblaster-1 Sandblaster-2 Sandblaster-2 Sandblaster-2 Sandblaster-2 Sandblast ei^2 Sandblaster-2 TIME ON 10:52 11:01 11:00 11:07 11:09 11:18 12:50 13:04 13:09 13:17 13:24 13:34 13:48 14:06 14:17 JK-41 JK-42 Sandblaster-2 Sandblaster-2 14:35 15:00 JK-43 JK-44 Sandblaster-2 Blank 15:21 TOTAL TIME (minutes) 16 6 17 11 14 8 5 11 5 7 9 14 17 11 17 FIBERS/CC 4 D.L. 0.38 0,40 0.67 0.45 < D.L. 4 D.L. < D.L. 0.95 0.60 0.66 < D.L 0.32 0;19 0.40 25 0.23 21 No count possible 15 0.46 0.01 COMMENT On lift above #1 #2 above on lift #2 still above Blasting time: 9 min Blasting Bare Metal Area. Man lift Ground Blasting time On man lift 6 min On lift On lift 7 min blastir. Lift 11 min blastir. Lift Lift Blasting over operator's hea (cat walk) Lift 15 min biastin Lift 11 min blastir Lift fibers/field (100 fields) D.L. *= Detection Limit All samples Operator Breathing Zone -29- APPENDIX C Table 2. Pot Tender Time Weighted Average Asbestos Exposure SAMPLE TIME(Min.) C, PIBERS/Cir CALCULATIONS JX-2 JX-4 JX-8 JE-9 JX-16 JX-20 JK-23 JK-2B JX-31 Unsampled 27 37 20 12 22 22 17 18 8 182 0 0.35 Ho count 0 0.17 0.24 1.02 0.40 0 0.28* * Average Exposure = CT = concentration AT of unsaapled. TWA = JCT 480 = 97.5 * 0.20 480 0.2 fibers/ca , >5 * C = fibers/ca3 T = Time (minutes) Sandblaster. #1 Partial day time weighted average. SAMPLE TIME (Min.) 03 PIBERS/C2T CALCULATIONS ' JK-1 JZ-5 JX-6 JJ-24 JX-27 JX-29 JK-34 27 20 17 16 6 11 5 0 0.49 0.57 1.27 0.88 0.67 0.95 No exposure between JK-6 &nd JK-24* TWA = CT =57.2 =0.1 f/cm3, 480 480 C = fibers/ca"* T - Time (minutes) -30- AtTl^UlA ^ Table 2. (Ccntimed) Sandblaster 2. Time Weighted Average Asbestos Exposure. SAMPLE TIME.(Mia.) ------------c------------------PIBERS/CM3 CALCULATION JX-5 JX-7 JX-11 JK-12 JX-13 JX-14 JX-15 JX-17 JX-18 JX-19 JX-21 JX-22 JX-26 JX-30 JK-32 JX-33 JX-35 JX-36 JX-37 JK-38 JX-39 JX--40 JX-41 JX-42 JX--43 Unsampled . 11 16 5 6 8 Overlap 12 Overlap 7 10 11 18 16 17 5 11 9 9 15 17 12 17 12 17 25 52 Marred 0.31 0.63 0.71 1.4 JX-15 0 JX-15 1.3 0.3 0.32 0.91 0 0.45 0 0 0.6 0.66 0 0.32 0.19 0.40 0.23 Ho count 0.46 0.38* Average exposure = CT = concentratior f I of unsampled TWA = CT 480 = 130.4 = 0.27 480 0.3 fibers/cn , >5 M C = Concentration (fibers/cm3) T = Time (minutes) - . * Average Exposure -31- A V.; G. ATTACHEMENT II Union Carbide Report of Cooperative Air Monitoring at Village Grove Park. I\ AIRBORNE ASBESTOS COUNTS for Textured Coatings of America, Inc. (Village Grove Trailer Park, Lots 19 and 20) Corona, California Date Sampled: December 17, 1976 Date Reported: April 1, 1977 Samples Collected By: B. L. Ingalls Union Carbide Corporation Samples Analyzed By: B. L. Ingalls & G. J. Spencer Union Carbide Corporation Reported By: H. B. Rhodes Union Carbide Corporation Union Carbide Corporation Metals Division Niagara Falls, New York -32- f-'; r OBJECTIVE -1- To measure the airborne asbestos fiber concentrations generated during the removal of an asbestos-containing maintenance coating from a sheet metal fence by sand-blasting. DESCRIPTION OF OPERATION The test was run at Village'Grove Trailer Park, Lots 19 and 20 in Corona, California. The park was surrounded by a galvanized rnetal fence about 5' high that had been painted about five years previously. The metal was first primed and then painted with an alkyd-based maintenance coating containing about 5% asbestos. The paint also contained mica, talc (non-tremolitic), fiberglass, and perlite. The sandblasting was done with a portable unit consisting of a compressor and a blasting unit. The latter had a sand storage tank about 1' in diameter by 3 1/2' Tong which fed silica sand through a lever operated control device and a heavy hose to a blast nozzle, under the control of the operator. One man handled the blasting nozzle while the other operated the compressor, assisted with the hoses, but primarily operated a lever on the sand delivery unit to keep the sand flowing. The nozzle operator wore a conventional sand-blasting hood with air openings on the sides. . During the blasting operation one man stood about 2' from the fence and moved the nozzle, held about 3-6 inches from the fence, in short arcs until the impinging sand removed the paint down to the base metal. Bonding was excellent and it took at least several passes of the blast to remove the paint. The material removed was finely pulverized. The bottom 1 1/2' of the fence was not hand-blasted to avoid raising extraneous dust from the dry ground at the base of the fence. The weather was clear and warm with a light, variable breeze blowing from left to right in approximately the same direction as the fence. SAMPLE COLLECTION The following types of samples were collected during the test: 1. Background samples prior to testing were collected at the fence, ~4 1/2' from the ground about 100' apart. (Spanned the section to be sand-blasted.) (G-16 & F-44) 2. A sample about 40' downwind, on the fence about 5' above the ground, during the last 25 minutes of sand-blasting.(G-3) 3. Personal samples on an observer in an area generally 25-35' from the blasting operation and approximately perpendicular to the blasting. (A-86, A-81, J-89) 4. Personal samples on both the helper and the sand-blasting operator. All operator samples were external to the hood except X-2. Helper - G-48, X-8, C-15, X-4 Operator - D-71, X-14, G-34, X-2, X-3 A ,f ' -33- -2- COUNTING EQUIPMENT AND PROCEDURES All samples were collected with battery-powered air pumps (M.S.A.), calibrated to 2 liters per minute on Millipore membrane filters of 0.8y porosity. The samples were mounted and counted in accordance with the procedure of Bayer, Zumwalde, and Brown (Bureau of Occupational Safety and Health, February 1969). Counting was done with a Nikon microscope at 40CX utilizing a Poton reticle with a 0.0062 mm2 field area. One hundred fields were counted for all samples. These samples proved to be particularly difficult to count. Out of the total of nine personal samples from the blast operator and the helper, six were loaded with dust to a level where filter areas were frequently obscured. When such an area occurred, the counter went on to another field. There is no way to tell how this may have influenced the results. Our normal practice in this situation is to resample, but considering the difficulties this would entail, the filters were used. In addition to this problem, the nature of the samples puts an extreme strain on the method. Thus: 1. Fiber concentrations were low with 0.58 fibers/field the maximum and 0.2 fibers/field more or less typical. This is well below the 1-5 fibers/field range recommended by NI0SH. 2. The fibers counted were in the 5-15y range so that the "5u decision" was a frequent requirement. 3. There were substantial concentrations of mica "chips" present. These can generally be recognized as not asbestos but certain shapes around 5y in length can become undistinguishable. These factors of low fiber concentration on the filter, filter size distribution, and potentially interfering "fibers" result in a high degree of operator discretion in the determination of the total number of asbestos fibers counted. When this possible variation is combined with the short sample times substantial variations can result. In view of these uncertainties, a modification was made in the procedure to report two categories of fiber: 1. Obvious chrysotile asbestos. Either long and curved, or distinctly thin and slightly curved in the 10-20p range. 2. Possible asbestos fiber: Particles which did not have obvious identifying asbestos features but met the L/D >3, >5u require ments and were dark and fiberlike under phase-contrast illumination. When there was any doubt about a fiber's identity, it was included in the appropriate class. The total of both classes would be the value ordinarily reported as asbestos. Particles which were obviously not asbestos were not counted. This would include such things-as unbroken fiberglass, mineral flocks with non-parallel sides, and particulate that appeared bright under phase contrast. It should be noted that the only known source of asbestos in this formulation was the 5% by weight chrysotile. (Note that the 2% asbestos figure reported by DOSHA in Appendix B is in error.) i\ J ! / -34- -3- RESULTS AND DISCUSSION A description of each sample and the respective fiber concentrations are shown in Table I. The data obtained by Counter A are presented graphically in Figure I. Where paired results are available Counter B was high six times and Counter A three- times. The differences, without regard to sign ranged from 0.1 to 1.1 fibers/cc and averaged 0.3 fibers/cc. In view of the counting difficulties on these slides we consider this to be good agreement for operators in the same laboratory counting the same slides. The operation of the sand-blasting equipment was too erratic to provide a meaningful estimate of operator TWA exposure for normal oper ation. Using just the time periods during the actual blasting operations, the time-weighted averages were: Operator (10)(2.2)+(ll)(3.2)+(8)(3.28)+(14)(1.68)+(22)(1.76) _ 145.68 (10)+(ll)+(8)+(14)+(22) 65 2.2 fibers/cc >5y Helper - (10)(1.Q3)+(23)(l.1)+(14)(0.15)+(22)(0.06) (10)+(23)+(14)+(22) _ 39.02 69 _ 0.6 fibers/cc >5y The measured TWA exposure for this particular 8-hour day would then be: Operator - 145.68 480 = 0.3 fibers/cc >5y Heiper - 39^Cj2 = 0>08 fibers/cc >5y A -35 TABLE! SUWIARY OF AIRBORNE ASBJSTOS FMCR COUNTS PUKING SAN0-KLA$TTmG~01f 'ASr.rSIUS-COhTAlKri.y KAIUT'tllAircr'COATlUr, Description of Operation Pretest Controls On fence, left side of area to be sand-blasted. ~4 1/2' above ground. On fence,^100' from G-16. --5` above ground. Personal sample on observer **25' from fence and moving Sample Oata 1 tme Total Ho. On Off Hin. G-16 10:35 10:56 21 F-44 10:42 10:59 17 e A-86 10:39 10:52 13 Airborne fiber Concentrations (Fibers/cc 5u)_____________ Obvious Chrvsotile fibers 100 fields f/cc Operator *A" Possible Asbestos fibers 100 fields ilss. Total Asbestos fibers 100 fields Operator *B* Total Asbestos fibers 100 fields f/cc 00 2 0.07 2 0.07 00 00 00 00 2 0.08 2 0.11 2 0.11 4 0.21 Comments Observer (During Sand-Blasting) Personal sample on observer A-Bl 11:12 11:18 --20-30' from fence and moving 11:25 11:27 parallel to fence. Same as A-81. J-89 12:26 12:52 Area sample on fence. 5* G-3 above ground and "40` down wind. (In lieu of observer) 1:35 2:00 6 2 8 26 25 Helper (Purina Sand-Blasting) Personal sample. Assisting with hoses. Operating sand feeding equipment. G-48 11:10 11:18 8 11:24 11:26 2 Iff Same as G-48. X-8 12:25 12:48 23 Same as G-48. Same as G-48. C-15 X-4 1:08 1:36 1:22 14 1:58 22 Blasting Operator (Purine Sand-Blasting) Personal sample. Operator handling sand-blasting noaale, standing--2' from fence. 0-71 11:10 11:18 8 11:24 11:26 2 Same as 0-71. X-14 12:2S 12:36 11 Same as 0-71. 6-34 12:38 12:46 8 Same as D-71 except Inside of hood. Same as 0-71. 1-2 1:08 1:22 14 X-3 1:36 1:58 22 00 1 00 1 7 0.19 22 0.09 1 0.03 0.61 1 29 0.09 0.03 0.7 - 21 0.6 1 0.07 14 * 10 0.30 18 - - 1 0.05 2 00 2 0.97 IS 0.54 * 0.10 0.06 28 45 3 2 1.03 9 0.84 1.35 0.15 0.06 60 9 0.6 1.8 Heavily loaded: ha to count second si 0.3 7 0.48 25 1.72 32 2.21 13 0.82 30 - 5 0.43 33 8 0.39 26 21 0.66 35 1.88 2.84 1.28 1.10 43 58 38 34 56 2.70 3.64 3.28 1.68 1.76 75 39 S3 Heavily loaded, ha: to count. 4.70 3.36 - Heavily loaded; ha: to count second si Heavily loaded; ha: to count. 1.66 ') 36 /i4? Z 0 0 /1-W s.r, / / JJ /o o 198_-V_ I. V) P- Se A ^e* i<.s 31 1 I 1 I - G-3 Xi AIRBORNE ASBESTOS FIBER COUNTS DURING SANDBLASTING C9 rr O -3 2 li <UUoozcJi <oz ocoozzkc> <n 1 S < o 1 uV1. "V ci/ HELPED IA O1 k a> T i 00 1 o1 9k9 *X11 1 zoo u Me K 1 11 v>1 r ^i 1 Xi <ila35a*k3ee* 2 <-J ED oz< IA 1 c - j /O '*/}.*. /O '- ) / iS. / / i f "S 33/*JaqH ` s< 33/uaqu Q -37- > <-> y S 33/t4aq|j 7-' ' W J ^ LL H. ATTACHMENT III Protocol of Cooperative Air Monitoring Test at Kerr-McGee, Trona, California. A ooO UNION CARBIDE CORPORATION METALS DIVISION P. 0. BOX 579 . NIAGARA FALLS, N.Y. 14302 TEL: 716-278-3376 January 13, 1978 Mr. James Heacock Occupational Health Section California Department of Health 2151 Berkeley Kay Berkeley, CA 94704 Dear Mr. Heacock: The suggested protocol for the cooperative test that we discussed in your office is attached. As you requested, it has been set up so that the Department does the actual sample collection. Plans are well along to conduct the test on one or more large tanks in the Trona area that have been coated v/ith zinc-rich primer. The only hold up is satisfactory verification of composition of the primer. We-would like to go ahead and plan to conduct this test during the week of January 23, 1978, preferably on Tuesday the 24th. Please let me know if this is satisfactory so we can finalize on a date and the other arrangements. In view of the time that has passed since the original hearings and the number of new people involved, it seems appropriate to comment on two questions relevant to the previous testing results reported in a letter of June 1, 1977 from Jerome A. Lockner, M.D. to the Honorable Jack R. Fenton, i.e.: 1. The appropriateness of sandblasting as a representative test method. 2. The accuracy of the previous counts. We have been informed by a large manufacturer of the high-performance mainten ance coatings of particular interest here that certain of these coatings are sandblasted as a routine procedure. Usually it is a light "brush" blasting to remove rust spots and loose coating but occasionally complete removal takes place. Sandblasting thus represents an extreme condition and should thus be a reasonable way to approximate the upper limits of exposure. -38- A 'J Mr. James Heacock -2- January 13, 1978 As we discussed several times, in the test where Cal/OSHA and Union Carbide collected side-by-side samples during a sandblasting operation, both laboratories found asbestos counts of several fibers/cc or more when counting by the routine NIOSH procedure. It is well recognized that the procedure has very serious limitations for dusts of the type generated during sandblasting. Subsequent examination by Union Carbide of several of the filters using scanning electron microscope techniques suggested that both laboratories may have counted substantial numbers of non-asbestos particles as asbestos and that free asbestos fibers were extremely rare. Over the past year the Federal OSHA Laboratory at Salt Lake City has adopted more sophisticated optical techniques to distinguish asbestos from other particulate matter and are quite possibly the most skilled laboratory in the country in this.area. I have discussed our problem with the Director, Mr. Floyd Madsen, and he is agreeable to count a reasonable number of samples. It will be appropriate for you to make a written request for this assistance at the time the samples are submitted. Please let me know if you have any problems with this proposal.. We are looking forward to participating in what appears to be the first carefully defined test of asbestos exposure in this type of application. It was a pleasure meeting with you and the others in Berkeley. . Very truly yours, - /3. Harrison B. Rhodes Technology Manager HBR/rmm Attachment -39- n A/ TEST PROTOCOL OBJECTIVE The objective of this test is to measure the airborne concentration of asbestos fibers generated during the removal of a non-resilient maintenance coating by sandblasting. The site selection, test operation, sample collection, and sample analysis will be carefully planned in advance so that meaningful results are obtained. WORKING ARRANGEMENTS The selection of the test site and provision for the sandblasting operator and equipment are the responsibility of the Union Carbide Corporation with the choices subject to approval by the Department of Health. It is intended that the Department of Health and Union Carbide will each have at least one qualified person at the site to work out a mutually acceptable sample collection strategy in accordance with the general guidelines under "Sample Collection Strategy". Sample collection will be performed by the Department of Health.. After collection is completed, a validated summary sheet of the collection data will be prepared with a copy for both participants. In order to expedite matters, the cassettes will be packaged and sent immediately by registered mail to: Mr. Floyd Madsen, Director OSHA Laboratory 390 Wakara Way Salt Lake City, Utah 84108 The Department will send a confirming letter to Mr. Madsen requesting them to analyze the samples. He has been alerted and is expecting to receive 10-30 -samples. When analysis is complete, the OSHA Laboratory will provide both participants with a copy of the results. TEST SITE AND OPERATION CRITERIA The following criteria apply to test site selection: 1. Reasonably representative of a substantial commercial use of the product. 2. Large enough to allow for several hours of dust generation. 3. Reasonably unambiguous definition of the composition of the asbestos-containing material being handled and an asbestos content in the upper part of the range of contents of interest. 4. Sandblasting will be done with regular commercial equipment and materials by a professional operator in a manner that is accepted comnercial practice. -40- ; -2- . SAMPLE COLLECTION STRATEGY As noted previously, it is intended that the Cal/OSHA and Union Carbide representatives at the site work out the most appropriate sampling strategy with the following special provisions to be met: 1. Personal breathing zone samples will be taken on the operator and the helper (if present) that are subject to the highest exposures. In addition to samples collected during the actual operations, a reasonable number of samples will be collected before and after operation to permit an estimate of the 8-hour time-weighted average exposure. 2. Area samples upwind and downwind will be taken before, during and after the dust generation operation. ADDED NOTE The Union Carbide Corporation is participating in a national round-robin study of the NIOSH collection and analytical procedure. It has been agreed that we may have an observer wearing a pair of pumps moving in the immediate vicinity of the dust generation operation. Care will be taken that there is no interference with the test. These samples will be entered into the round-robin and since they will be counted by only the standard NIOSH procedure, the results are not relevant to the present tests. SAMPLE ANALYSIS - All sample cassettes will be shipped unopened to the Federal OSHA Compliance Laboratory at Salt Lake City. _<n_