Document v6mZDGq585G7ZbYzbZ35XmNe6

United States Department of the Interior BUREAU OF MINES Denver Federal Center, Building 20 Denver, Colorado 80225 Health and Safety Technical Support Center January 28, 1972 Mr. F.H. Larrison, Resident Calidria Asbestos Plant Union Carbide Corporation Mining and Metals Division Box K King City, CA. 93930 Manager R C i V -c. 3 FEB 1'97? ucc - CALior.:.\ kins -;ty. r: Dear Mr. Larrison: Enclosed is a report covering the asbestos dust (health) survey of October 4-6, 1971. Thank you and members of your staff for cooperation during the survey. * Sincerely, Glen W. Sutton Chief, Denver Technical Support Center cc: R.J. Kronkhyte, Maintenance Supt. and Safety Engineer UCC 023915 UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF MINES HEALTH AND SAFETY TECHNICAL SUPPORT . HEALTH STUDY (ASBESTOS DUST) ' KING CALIDRIA ASBESTOS PLANT KING CITY OPERATION UNION CARBIDE CORPORATION CITY, MONTEREY COUNTY, CALIFORNIA October 4-6, 1971 By Walter Bank, Mining Engineer Amin N. Alameddin, Mining Engineer Kenneth L. High, Mining Engineer V ti Z-JL r 4i,i -- hr'. /'/ .. - 9 - /s.cWv'V-a >/-risiiy' DENVER TECHNICAL SUPPORT CENTER Mr. Glen W. Sutton Chief Originating Office S. Bureau of Mines, Health and Safety Technical Support Center Denver Federal Center, Building 55 Denver, Colorado JJ0225 4-7953 UCC 023916 UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF MINES Mine: Calidria Asbestos Plant Company: Union Carbide Corp. Mining and Metals Div, Operated by: same as above I.D. No: 40013-00-04-027 Underground ___ Open Cut __ Survey by: Walter Bank, Amin Alameddin, and Ken High Location : King City, Moriterey County, California Survey dates: October 4-6, 1971 DISTRIBUTION: Company officials: F.H. Larrison, Resident Manager (3) R.J. Kronkhyte, Maintenance Supt. andt Safety Engineer ' Assistant Director--Health and Safety Technical Support (2) Assistant Director--Metal and Nonmetal Mine Health and Safety (2 Originating office: Technical Support Center, Denver, CO. (2) State agencies: California Div. of Industrial Safety Dept, of Industrial Relations 455 Golden Gate Ave. San Francisco, CA. 94102 Attn: Walter Van Sandt (1), Edward Davies District Manager: Allan Look, Alameda, CA. Subdistrict Mgr: Howard Poland, Alameda, CA. /> (1) Other: Ernie Piersol, Safety Director Mining and Metals Division Union Carbide Corp. P.0. Box 1049, Grand Junction, (2) ' CO. 81501 UCC 023917 A 17 954 4. A metal, open-sided product storage shed of 10,960 sq. feet. 5. A rubberized-cloth inflatable building of 6,426 square feet. An ore stockpile, estimated to contain about 35,000 tons. was located across the roadway, Ore was delivered to the stockpile by a 25-ton capacity truck and trailer, dumped on top the stockpile, and pushe d by a bulldozer to blend the ore and to provide a more 1 evel surface or roadway for the ore truck. A front-end loa der with a 2 1/2-yard capacity bucket trammed ore from the sto ckpile to the loading point which leads to the COM bin - th e start of the ore processing. A tailings pile, estimated at 15,000 tons, was immediately adjacent to the ore stockpile, Product recovery was 50 percent; the 50 percent wet tailings was stacked by means of an in dined belt conveyor. When the waste pile becomes too large and overflows onto the roadway, the waste pile is cut down to size and the waste is hauled to a nearby ravine by a means of self-loading paddle wheel scraper. While the dust survey was in pro ces s, M. W alter A. Van S andt, Indus t ri al Hygiene Engineer and Mr. Ed D av ies , Safety En gineer of th e Cal ifornia Department of Ind us t ri al Relations vis i ted the o pe r at ion , discussed our s ampli ng te ch niq ues, coll e c ted sever al s a mple s for record purposes and f urnished the write rs wi th i nformation on this an d oth e r asbestos pi an ts . DESCRIPTION OF STUDY Asbestos airborne dust is the overriding health hazard in a plant of this character. Airborne asbestos dust has been demonstrated to cause the pneumoconiosis called asbestosis and lung cancer. All control measures applicable to mineral dust control can be used for airborne asbestos; however, the more hazardous nature of asbestos re quires more stringent adherence to good control practice s. At the Calidria mill, the following conditions and practi ces were noted: 1. The stockpile was kept wet most of the time. Reportedly, the ore contains 20 percent moisture. 2. Prevailing winds are from the north, and blow the stock pile-created dust away from the mill. 2 A UCC 023919 15. A medical surveillance program was reported in effect. The reported program included a pre-employment physical examination followed by an examination every three years until age 40; thereafter, an annual physical examination is p rovide d. During the survey sampling, the weather was clear and dry with a slight wind blowing intermittently. At noon, the temperature was about 90 degrees and the humidity was about 13 percent. . The effectiveness of the control measures will be dis cussed later in this report. ' Sixty-six sample's were collected. Of these, two Nuclepore samples were submitted to Dr. Phillip DeNee, Safety Research Center, Bruceton, Pennsylvania for evaluation. Results of his work will not be included in his report. A settled dust sample and a sample of the purified product, collected from the filter press, were submitted to the Field Health Group analytical laboratory; results of these analyses are included in Appendix I. Sixty-two airborne asbestos dust samples were collected on membrane filters using pumps > calibrated, at the mill office to pull 1.4 liters per minute of air; these samples were counted in the DenveT Field Health Group laboratory at approximately 460 magnification with phase contrast illumination according to the method established by the U.S. Public Health Service. Full-shift exposure samples were collected of three individuals who were exposed presumably to high asbestos dust concentrations; sufficient samples were collected of other representative individuals or of locations where men worked to indicate the dust exposure levels. DISCUSSION AND RESULTS In 1967, the published TLV 1_/ was 5 mppcf (millions of par ticles per cubic foot of air) fj^_asb>iS^b>e>ariri_dus_t^ when collected conventionally with the impinger or midget irapinger and counted conventionally with the standardized light-field counting method. The number concentration represented the visible fragments (small) of asbestos fibers plus the many associated mineral dust particles. In 1968, the published "Notice of Intended Changes" proposed that (1) the 5 mppcf be reduced to 2 mppcf; and (2) an alternative figure of 12 fibers/ml (.fibers per milliliter) greater than 5 microns in length be adopted -- this figure 1_/ Threshold Limit Values for 196 7 , Reconmen ded and Inten ded Changes; American Conference of Governmental Indus trial Hygienists, 1967. f 4 A i 7 950 UCC 023921. was to be based on the membrane filter method at 430X phase contrast magnification. The above two proposed changes were retained in 1969; in 1970 the published proposed changes (1) dispensed entirely with the impinger sampling method and its number concen tration figure; and (2) recommended that the alternative value be changed from 12 fibers/ml greater than 5 microns in length to 5 fibers/ml greater than 5 microns in length. In 1971, the "Notice of Intended Changes" retained the 1970 proposal, and specified the membrane filter method at 400-45QX magnification phase contrast illumination. Also, an excursion limit not to exceed 10 fibers/ml may be per mitted for 15-minute periods each hour up to five times daily. For purposes of this health study, it is believed that the 1971 proposed TLV figure and sampling method provides the ' best indication of the asbestos dust health hazard. Thls,, value has also been accepted by the U.S. Department of 5 Labor and on December 7 an emergency standard of 5 fibers/ml was published in the Federal Register. Therefore, the pro posed 5 fibers/ml (on a time-weighted basis) is used as tiie threshold limit value. Fiber concentration and pertinent data for the individual airborne dust samples are listed In Appendix II. Fiber con centration data are summarized in Figures 1, 2, and 3. Figure 1 summarizes the time-weighted exposures of three men. The bagger operator was exposed to eight times the TLV and had a one-hour exposure of 12 times the TLV figure. The palletizer operator, working nearby, was exposed to 6 times the TLV and also had a one-hour exposure of 12 times the TLV figure. Both men were provided with U.S. Bureau of Mines approved respirators which they wore when working in obviously dusty atmospheres. The exhaust system at the bagging operation was inadequate to control the spillage and dust emission, and as the newlyfilled perforated multi-wall bags were conveyed to the palletizer, dusty air seeped from the bag's pores and con tributed to the asbestos dust load of the ambient air. When bags broke during the bagging operation, the exhaust system at floor level failed to capture the spillage; sweeping the dust spillage to the floor launder contributed to the dust load in the air. As previously mentioned, an additional dust-collecting system was in process of installation at this area. 5 UCC 023922 A v7 952 The exhaust system at the top of the palletizer admittedly was not working properly and required repairs. When broken, bags were dropped to the floor beneath the palletizer, and subsequently the bags and asbestos were removed. The foreman's time-weighted exposure was 7.6 fibers/ml with one sample recording a one-hour exposure of four times the TLV figure. The foreman made his rounds unaccompanied by the man collecting samples. The source of the dust con tributing to the foreman's exposure is considered (provisionally) to be the general mill atmosphere. Other workers' airborne asbestos dust exposures were obtained on a when-sampled basis. As shown in Figure 2, the exposures of the mechanic, the bagger of the resin-grade asbestos, and the filter-press operator were within acceptable limits when sampled; the exposure (arithmetic average) of the loader operator was six times the TLV figure with a one-hour ex posure of eleven times the TLV figure. A number of working areas were sampled to assist in evaluating the workers' exposures; the airborne asbestos fiber concen trations are summarized in Figure 3. Mine yard "general atmosphere" samples collected during the greater part of the workday suggest that wind dispersal from the ore stockpile or tailings pile was not a significant factor in the workers' samples collected in the mill. But it is recognized that at times the wind direction and velocity may become significant factors in contributing to a hazardous dust environment. Low asbestos fiber concentrations were obtained in the accounting office, the main (upper floor) office, the welding shop, and the assay office. The roll mill area of the mill had an arithmetic average concentration of 8.0 fibers/ml. The high concentration of 17 fibers/ml of sample B-105 indicates a need for better dust control.measures at this "wet" operation. The cause of this high concentration was not apparent. The foreman's office sample results yielded an arithmetic average of 7.5 fibers/ml with a high concentration in sample B-23 of 11 fibers noted between 1:38 and 2:38 p.o. The office door opened to an area partitioned from the dusty bagging and palletizing area, so the specific cause of these concentrations was not obvious. The dust concentrations are provisionally attributed to the ambient air dust load and the dust from the workers' clothing during the time they occupied the office. _ 6 9~7 /o UCC 023923 To diminish the exposure of the loader operator, the following recommendations are made: 1. Keep the stockpile wet. 2. Provide an enclosed cab with filtered air on the loaders; the-spare loader in use during the survey did not have such a cab . 3. Improve the housekeeping in the immediate area. For example, the concrete ramp leading to the conveyor system was hidden beneath spilled ore. The use of respirators in the work area shall not be con sidered as a substitute for engineering controls and their continued use over prolonged periods shall not be permitted. However, to protect the workers prior to the application of engineering controls which result in exposures and/or con centrations below the standard, respiratory protective de vices shall be provided, maintained and their use required. The respiratory protection program shall include adequate3, training and supervision of employees in the testing of respiratory protective devices for fit before their use. The employees shall be required to test his respiratory . protective device before each use in order to insure a proper fit. - Respiratory protective devices to be used shall be limited to the following: 1. For an atmosphere containing not more than 25 fibers/ml greater than 5 microns in length over an 8-hour average or more than 50 fibers/ml over any period of 15 minutes, a reusable or single-use filter type respirator, operating with negative pressure during the inhalation phase of breathing, approved by the Bureau of Mines under Schedule 21 shall be used. B 2. For an atmosphere containing not more than 250 fibers/ml greater than 5 microns in length over an 8-hour average or more than 500 fibers/ral over any period of 15 minutes, a powered filter positive pressure respirator approved by the Bureau of Mines under Schedule 21 B shall be used. The tailings pile, when dried, is an obvious source of air borne dust during windy conditions. Keeping the tailings pile wet continuously and removing it to a more distant lo cation will minimize dust conditions in the mill, shop, and office areas; however, other measures must be taken to mini mize its impact on the community environment. . 8 A . 7952 UCC 023925 A i 7- 9 3 3 h9* < P> UCC 023926 z F ig u re 1. A sbestos F ib e r C o n c e n tra tio n s in M ill, T im e-W eighted E xposures 2 ST 4 n3 3 3 rf p. O 3 M 3X c -i (mD 3 HS* I I O 3 3 sr (D 3 03 3 3a H* n> o. n 33 H* 3 a A i 7 9 8 -r UCC 023927 HFj OQ C H 10 LJ o ro 3 1(0 >oa o* (0 H to o rr O05 oB H* o* 15 3 H mO h to O 3 O o 10 33 r* H 3 s: <0 3 I Crt 3 T3 h-1 ra CL w 3 m H* m Asbestos Fibers/ml-, >5 microns in length 2O! I O 1--1 H* M NJ ^ Hi in Q l*n o- in o CQ 3 T33 ro 0 Lower office, accounting UJ Upper office, main I Cj r Jc-i Electrical shop k FSU) [. , . -O -- Jj Welding shop 3 lAo o> t* o I es >H <(B 3* fi Co 3fO TO ! TO =r A ' 7 9 S UCC 023928 APPENDIX I Mineral Analyses S ample No. B-902 B-904 Des crlption Percent Free Silica Filter-press product ' 0 ' Settled dust near COM bin 4 Remarks Diffractometer scan showed broad lines identified as being from serpentine 1/ Same 1/ Additional mineral and elemental information will be added to this' report when available. . UCC 023929 A,7963 b a g g in g . b a g g in g ao 4 no M H 41 s J6 H U0 A c o H 4J ca 14 4) & o **. s o H 4J 4) O o - o fn CM rH \0 cO CM CM U") U*! N m Ln <3* * 60 c 00 v0 a 60 H C oo JJ *H C to CO * H 00 M 00 4-1 00 CO 4) 0 u OO CO N cQ 60 H <-3 o c JJ *r-> 0) * 60 rH O o 60 rH 03 CL M a> d <0 * "D cfl 03 *H o CQ & *d jo oo a) o a* S o G> * " >4 * -H 3 * A * u JJ u CL M rJ jo Li nu * o o o -i4 d o O o o Dm o H o T3 o h oG oo3 tH *H rH 4> 1-4 4) CO 1-H rH rH rH c m 4h 00 tH 1--t tS <44 mh 4-1 03 3h oo rH 0) i--i O i--t <0 rH 03 f*H rH rH rH rH .rH 4H rH,, 43 rH CL a i-4 H rH rH CJ tH *H *t4 t -H H iH *H 33 s 22 cn 2 33 X X CM . 00 CM CA <30 rH sr CM o <r VO <33 a: 60 oc a 60 G H 03 * C ca N G 60-H G 60 i4 a) C 4J 03 d JJ JJ H CO JJ H 03 G 60 M e 60 i-4 *tH 60 4J *H 60 i-4 <a a, ca 0 * J3 O 0 CL 03 a CO * . u u JJ i-j * Aa M 3-4 =< O * o o Mh o O O d o o o 0 H o u o Q rH t/J rH rH rH rH to rH rH a) m rH <4H 4H J*J MH rH 4h hh 0 S-i 0 rH rH H 0 rH *H rH rH rH rH 4H tH rH rH H -rH *H *rH *H tH s xs s flo o r, flo o r, MM ii ll ll * APPENDIX I I 1434 1600 1334 1434 14 O 4J at <u a. 0 |4 0o1o 00 o4 >- pq om co -a- Mf r- n o m m vo o o co n o ca o rl M Cl -} oo ot c rH JJ U r-- o CO <n m M3 O 0 G O u"\ <r cn cn cn CO cn ed JJ oo oo o> o rH CM ro *<r W CO o O o rH rH rH tH rH VJ 4) N to CL, o oo i-i o oo -<f omo vr -locti o co cA CM CO o O i-i M3 rH O CO O U-i < <3- CO 00 a\ o rH CM O o o rH rH rH O' m to oo a. o o r** --i 'S' e z 1--f 4T r- r4 rH <--l CH CM ca 1 1 1 1 | r 3 1 L0 P5 93 pq 96 cq CO PQ w <r CO CM to oo rH rH 1 ii 1 Il pq pq pq CQ pq CD 95 CO UCC 023930 a ; 7967 11 2"" 2 25 APPENDIX II ' * UCC 023931 s ample No. B -3 Date 10/5/71 B -6 B -9 B -12 B -16 B -20 B -2 7 B -28 B -119 10/5/71 B -120 B, -12 1 B -122 10/5/71 B -123 B -124 . B -125 10/5/71 B -126 B -12 7 B -20 3 B -204 B -207 10/5/71 B -105 10/5/71 B'-111 B--116 Sampling Time Start Stop 0813 0908 0909 0949 1053 1206 1306 1403 1501 0949 1052 1206 1306 1403 1500 1601 1225 1330 1431 1325 1430 1531 1243 134 3 1345 1446 ' 1445 1546 130 2 1402 1402 1502 1502 1602 1050 1204 1204 1306 1306 1452 0923 1023 1025 1126 . 1125 1226 Job Title or Des cription Fo reman . Fib e rs /ml Loca tion/Operation >5 mi crons Asb es t os plant , rounds , BZ . s ame as ab ove. s ame as above. s ame as above. s ame as above. s ame as above. s ame as above. same as above. making ' 9.8 5.1 3.5 20 5.3 7.3 3.4 3.5 Me ch anlc Mill , va ried locations; repai r work , BZ . s ame as above. s ame as ab o ve. 0.1 0,0 0.1 Bagger, resin grade Mill, re sin grade bagging are a. misc. operations. s ame as ab ove. 8 ame as above. 2 .9 BZ. 1.4 1.4 Loader operat or Outsi de mill, tramming ore , B Z. s ame as above. same as ab ove. 11 20 57 Filter press ope rator Mill, fi Iter press op . press; BZ. s ame as above. s ame as above. , area. 0.5 0.5 0.23 Mill, TO 11 mill gen era,1 atmo. s ame as above. S ame as above . feed; 17 5.3 1.6 2 CQ CO CD APPENDIX II UCC 023932 S ample No. B -15 Date 1G/5/71 B-19 B-2 3 B-26 S ampling Time Start Stop 1150 1236 1237 1338 1438 1337 1438 1600 Job Title or Description Filter press operator Location/Operation Fibers/ml >5 microns Mill, foreman's general atmo. same as above. s a me as ab ove . 1 same as above. office; 9.0 6.9 11 3.3 B -201 B-205 10/S/71 10 30 1248 1248 1508 Mine yard @ flag pole; general atmo. same as above. 0.000.17 B -20 2 B -206 10/5/71 1040 1256 1256 1500 Mine yard, welding area; general atmo. same as above. 0.044 0.26 B -10 1 B -10 6 B-11Q 10/5/71 0815 0916 1017 0915 1016 1117 Assay lab.; general atmo. s ame as above. same as above, 1.7 1,9 0.12 B-102 10/5/71 0850 B-107 0952 B-112 'Nl 1055 CO B-103 10/5/71 0904 CD Cu B-108 1005 B-114 1106 0950 1052 1155 1004 1105 1206 i! Lower office, accounting; general atmo. s ame s ame 1.1 1.5 0.2 Electrical shop; atmo. s ame as above. same as above. general 9.3 0.29 0.10 B -10 4 B-109 B -11 3 10/5/71 0913 1014 1115 1013 1114 1215 Upper office; gene.ral atmo .0.99 s ame as ab ove. ' 0.33 same as above. 0.10 3 APPENDIX II Sample No . B-115 Date 10/5/71 B-I17 B-118 Sampling Time Start Stop 1242 1342 1342 1^42 1442 1542 Job Title or Description Location/Operation Fibers/ml >5 ml crons Welding shop; general a t mo, s ame as above. s ame as above. 0.31 0.73 0.00 UCC 023933 NJ O January 18, 1973 Hr. Frank Warm Senior Satfsfcjr Englaetr ^tate of California Dept. of Induetrisl Belatiana --iriroK of Industrial Safety T55C Maripoaa 5t.f Soaa *>065 !'r?mo, California 93721 lear Xr. Warrant - Aa required la your Accident Prevention Keport of 11-30-71* the tagging operator ha* boon provided* and is required to wear* an air supplied hood unit while parforsaiag tha Cities of bis jrt. Tie otter operator*, la tin pallatise* area* has been supplied with a 21-B rated cartridge type res pirator. The two opermtare are rotated during the shift bo that neither operator opcode full tine ia the cartridge respirator. Cur cospaxxy Industrial Hygienect* Xr* P. W* McDaniels* has checked the air supplied hood unit under operating conditions aad has dettrained that the hood internal ataoephera to leea than TLV. Very truly yours* Floyd H. Larriooa* Jr. Manager* King City Operations /clg cc: E. A* Pi email S. J. Krockhyte UCC 023934 A ; 7 97 1