Document 9J0rem22bOaJE8Joyq9xVN633

50983 DOW CHEMICAL U.S.A. *EXAS DIVISION = *EEPORT. TEXAS 775*11 ENVIRONMENTAL HEALTH REPORT ATMOSPHERIC CONCENTRATION OF ASBESTOS FIBERS WHILE CUTTING TRANSITE AT A-510 = u e Nn n-104 -.iTF April 19. 1973 --R.author L. Silverthome THFCKFri C. Y /date------------ Summery Concentrations of asbestos during the cutting of transite, using a water saw, was found to be below the standards set in the Federal regulations, but may be significant when considering possible carcinogenesis. During the cutting of transite without water the levels were above the standards. Attached is a copy of the survey with recommendations. Cirr ibution Emil Prihoda File A510 File No. M-164 -2- PROBLEM At the request of supervision, the Industrial Hygiene Department was asked to evaluate the asbestos hazard presented by the cutting of transite material. CONCLUSION (1) Asbestos fibers are liberated by the cutting operation in ~ significant quantities. 'c (2) The concentration of asbestos fibers found during dry cutting^ were as follows: (a) Breathing Zone of man doing cutting-------------------- 36.04 f/t (b) Breathing Zone of man doing cutting-------------------- 20Q444fc Avg..................................... 28.24 / (3) The concentration of asbestos fibers found during wet cutti were as follows: (a) Breathing zone of man doing cutting--------------------- .445 f/ (b) Breathing zone of man doing cutting--------------------- .267* f/ Avg.------------------------------ .356 f, Current government regulations allow no more than an 8 hour time weighted average concentration of 5 f/cc. The regulation also states that no employee shall be exposed at any time to airborne concentration of asbestos fibers in excess of 10 fiber/cc. (4) The current regulation governing permissible exposures to asbestos are based upon the possibility of contraction of asbestosis Asbestos fibers, however, have also been shown to be carcinogenic. No dose/disease relationship has been established, so efforts must be made to reduce and eliminate, if possible, the workers exposures. RECOMMENDATION (1) Cutting of transite material should be minimized if possible. (2) A water saw should be used whenever cutting is to be done. (3) The man assigned to cutting transite shall wear an approved dust respirator. (4) Work clothing should be changed and washed daily. (5) Environmental measurements should be made annually to determine the adequacy of precautions taken. 396861 File No. M-164 -3- RECOMMENDATIONS (continued) (6) A suitable periodic medical examination program should be arranged for employees exposed to asbestos fibers. DISCUSSION Asbestos fibers inhaled over a prolonged period can cause a pulmonary disease called asbestosos. This fact has been recognized for many years by those involved in the production and sale of asbestos. During the last few years a threshold limit value has been established for asbestos fibers in the atmosphere, the purpose of which is to prevent asbestos workers from contracting asbestosos. The current standard is 5 fibers/cc as recognized by the Federal Government. However, over the last few years respirable asbestos fibers have been recognized as being carcinogenic A dose/disease relationship has not yet been established, so no standard has been published prescribing the acceptable concentration of asbestos fibers below which cancers will not appear. For this reason exposures must be reduced to as low a level as is possible. This is done most desireably by reducing the exposure to the workers, and then providing protective equipment if the exposure cannot be eliminated. A total of 4 samples were taken on Milliport 0.8 micron 47 ton AAWG membrane filters. MSA Monitaire portable vacuum pumps calibrated and used. Used filters were cropped into 4 grid sections and immersed in 107. solution of diethyl oxylate and dimethyl phthalate on a slide, and then covered with a cover slip. When the membrane became transparent counting was performed using 40X objective and a 12.5X eyepiece, for a total magmafication of 500X. The eyepiece was equipped with a micrometer of 100 divisions 2.5 microne each. Phase contrast illumination was used. It should be remembered that the numbers given as the concentrations of atmospheric asbestos fibers is not to be considered as the absolute concentration, but the best technique presently known. Tests have shown that this method produces numbers that are difficult to reproduce from lab to lab, or microscopist to microscopist. However, it is the best technique we have. S&LP bbs 4-19-73 396862 2700 12-SO ENVIRONMENTAL SUK . EY SAMPLE RECORD 9UILOIN4 NO. ,4-57 0 j POCCSS UATCHIAl ON C H EMI C AL 5 if*oi lei~to s / Iran T, -<. SAMP LINO MET HO O A i ** SUPERVISOR ^"*r > ! Ps' i ha / <? TRAPPIN6 MEDIUM A" ' /tf < **- p Ct Q t \S" A'f 5 <4 REMARKS ^k' ** f /0 f - y / (3 C Ovt 1 ` 4 + <? P UMPtlM TE __ , y / - 2* ^ 7 V* 4 " ? **/M WIMO Ol R. EA/e cdoo * ) VELOCI TV /i TEMP. STOO 144-78 S T 00 I 41(79 File No. M-164 ASBESTOS IN ATMOSPHERE DURING CUTTING OF ASBESTOS TRANSITE Filter Factor = 154 SAMPLE NUMBER TIME SAMPLE. RATFfrlter,? 1 2 min. 2 2 min. 3 40 sec. 4 40 sec. 2.57 2.69 2.57 2.69 TOTAL VOLUME (Liters) 5.14 5.38 1.71 1.79 FIBERS 75 u Per Square (1) 15 (2) 1272 (3) 3 Filter Factor 154 154 154 Total Fibers 2310 195,888 462 Total Corrected Fibers (4) 240 154 36,960 (5) 0 154 0 Total Fibers 75 u Concentration = Total Volume = Fibers cc Fibers Per cc .445 36.04 .267 20.44 0 S&LP bbs 4-19-73 396864 50983 C?r DOW CHEMICAL U.S.A. _______________________________________ _______________________________ TEXAS OIVISION FREEPORT, TEXAS 7734 1 ENVIRONMENTAL HEALTH REPORT S I'UU 11(480 Concentrations of asbestos in the generail atmos*phere during the cutting of gaskets was found to be border line when compared to the Federal Regulation, but may be significant when considering possible carcinogenesis. Attached is a copy of the survey with recommendation to reduce the atmospheric asbestos fiber concentration. 1 Distribution Billy Parrack File A-2431 IQ VilO O iS PROBLEM At the request of supervision, Industrial Hygiene was asked to evaluate the tsbestos hazard presented by the cutting of gaskets in A-1876. CONCLUSION (1) Asbestos fibers are liberated by the gasket cutting operation in significant quantities and found in the atmosphere throughout the building. (2) The concentration of asbestos fibers found were as follows: (a) Breathing zone of man doing the cutting------- 4.03 f/cc (b) Breathing zone of man cleaning up area with broom-------------------------------------------------------------------------- 2.04 f/cc . (Note: Area has not been cleaned up for several days) (c) At top of stairway 15* from cutting table--5.44 f/cc (d) Breathing zone of man cleaning table off----- 3.08 f/cc with broom and picking up material off floor with a scoop. . NOTE: (a)*('d)were taken when the area had not been cleaned for several days (e) Breathing zone of man doing the cutting---- .78 f/cc (f) At top of stairs 15' from cutting table-------- 0 f/cc (g) In middle of shop downstairs during cutting- .12 f/cc (h) Breathing zone of man doing cutting------------------ .90 f/cc NOTE: (e) thru (h) were taken after the upstairs area had been cleaned up. Current government regulations allow no more than an 8 hour time weighted average concentration of 5 f/cc. The regulation also states that no employee shall be exposed at any time to airborne concentrations of asbestos fibers in excess of 10 fibers/cc. \ (3) The current regulations governing permissible exposure to asbestos- are based upon the possibility of contraction of asbestosis Asbestos fibers, however, have also been shown to be carcinogenic. No dose/disease relationship has been established, so efforts must be made to reduce and eliminate, if possible, the workers exposures. 396866 V u l I H U 'C File No. A24-L73 -3- RECOM>fENDATIONS (1) The gasket cutting device should be equipped with dust collection devices. (2) Cutting of gaskets should be done in an environmentally seperate area from the rest of the work area, to reduce exposure of other employees. (3) The man assigned to cutting gaskets shall wear an approved dust respirator. (4) Work clothing should be changed and washed daily. (5) A suitable periodic medical examination program should be arranged for employees exposed to asbestos fibers. (6) Environmental measurements should be made annually to determine the adequacy of precautions. c. DISCUSSION Asbestos fibers inhaled over a prolonged period can cause a pulmonary disease called asbestosis. This fact has been recognized for many years by those involved in the production and sale of asbestos. During the last few years a threshold limit value has been established for asbestos fibers in thd atmosphere, the purpose of which is to prevent asbestos workers from contracting asbestosis. The current standard is 5 fibers/cc as recognized by the Federal Government. However, over the last few years respirable asbestos fibers have been recognized as being carcinogenic. A dose/disease relationship has not yet been established, so efforts must be made to reduce and eliminate the worker's exposure. For this reason exposures must be reduced to as low level as is possible. This is done most desireably by reducing the exposure to the workers, and then providing protective equipment if the exposure cannot be eliminated. A total of 8 samples were taken on Milliport 0.8 micron 47 mm AAWG membrane filters. MSA Monitaire portable vacuum pumps calibrated and used. Used filters were cropped into 4 grid sections and immersed in 107. solution of diethyl oxylate and dimethyl phthalate on a slide, and then covered with a cover slip. When the membrane became transparent counting was performed using 40X objective and a 12.5X eyepiece, for a total magmafication of 500X. The eyepiece was equipped with a micrometer of 100 divisions 2.5 microne each. Phase contract illumination was used. 396867 File No. A24-173 -H- DISCUSSION (continued) It should be remembered that the numbers given as the concentrations of atmospheric asbestos fibers is not to be considered as the absolute concentration, but the best technique presently known. Tests have shown that this method produces numbers that are difficult to reproduce from lab to lab, or microscopist to microscopist. However, it is the best technique we have. o U U I ll4 U O S&LP bbs 4-19-73 / i 396868 i nn i s File No. A24-173 -5- ASBESTOS IN ATMOSPHERE DURING CUTTING OF ASBESTOS GASKETS Filter Factor 154 SAMPLE TIME (min.) 13 22 33 43 10 1 min. 10 sec. 20 1 min. 10 sec. 30 3 40 3 50 -0- Concentration SAMPLE . RATE L/M 2.57 2.69 2.69 2.57 2.69 2.57 2.57 2.69 -0- Total Fibers Total Volume TOTAL VOLUME (L) 7.71 5.38 8.07 7.71 3.13 2.99 7.71 8.07 -0- " Fibers * cc FIBERS 75 u PER SQUARE (1) 204 (2) 72 (3) 288 (4) 156 (10) 16 (20) 0 (30) 2 (40) 48 (50) 0 FILTER FACTOR 154 154 154 154 154 154 154 154 154 \ TOTAL FIBERS 31416 11,088 44,352 24,024 2464 0 308 7392 0 FIBERS PER cc - 4.03 2.04 5.44 3.08 .78 0 .12 .90 * 0 396869 81*1-1001S tltoo !** ENVIRONMENTAL survey sample record OUll OIWC MO. pmoccss UAAT-C/n.U?L 7OHt>CMCMICAC A. si */fc c ts / c/ Atn/t t^r T/' F IOUI.UCNT M *> A Pi** p uchf-alhekier 1**1 A FLOW IMOtCATOA SAMOUNC RATI "M"o ', wlla.;`i>r *-c I r,'//<t- velocity I^v TCI ! o ~/V L\ </. diC, ^fb < f/-?* -*--<----,- ///*/- <*; 41 u9d/r--4P/7ic-,! _/* / Contain- No. ar No. \o ~L 9* SAMPLE DESCRIPTION t'uyj T i , 'ro. aU,\ qa<fc.i:'t) Start TIME Stop SampI Valwmo Anolytia /;/o i./3 /C. f*1*4+ A -t f O T-e , >"/ * i- ilf *Cf X. 10 p'*** p / L^i yt>* ^ c. "t > '-f sLop -J sL**+*` tfi., L.yJ Tirol**** P---r H* V a rr /;/<? 2,^? S f"il 7,7/ 3 f.Ol f $ \^ 396870 5 I UU I 4 4 b b r.L*itOiN( r;0. MftOCCIt -i -1 >: 1L _ ./ C~t / y.TCIU.V. 04* CIIEWCL ( s bn v/.-s/r c c ? /Acsi- i-ld H t i*. * <4 J /.-I ' "> TY F COUIFUIH T r*l t H- ! - itO n Mu`"" $ .. 7 ii. 4>V ^ /4 > r ^ 7 /w#f i /^cif j*, * FI.OW INOlCAtO* I SAMUN9 flATK wu (NN. 1 VtLOCITr T CM _____^-- 1 __________ .. /? v. p_ ?_ _c . .W/K> ,. ,t--Y/ / M /-T (U / O *- < . ` 77 ; :-- - " v r ^ v ' /Vdflf fc- 7 ^ <7 t. A Li Ay 7<? / <. V" h c of * * i -* co* f< to o~ *-.'o/ s \* / "6 . T^ *- /l> ^ , "t 6 <- v*/ f ~f * * S -w ( d-<u 7 j o, H*.Sa*l. f H>. fa**? I SAMPLE DESCRIPTION /"l^i Cp _y C c o t""t u y * 5 4 ri~& s Cf os .<.is TIME Sih $< *;>*-*J V'SVAi To f,, / Z,-erj A J SNpl I VoU Afll|iii 7.7/ X c* ?>/./> x ^ , & 1/144 / 5 *r 6 /< 4M/ <a+ * c* ~:tu LiTOOt.it, . / 'j Y ^ ^ X "&tt ftVCty. ( * k**t~t\tiMy 'lOO*.') /*'0 "t Ctt ft4.l,v6 J;i7 2l*>" r.isr 7i /V*.p /4-f -i o f> o -h x "6ct /VvV 0 t^ dert o j t.-fr *, c 'f' c t * o f A -c *t> (T/ - i u ^ * ^ ~t*ip'/x_, T^blt. Arc p `,j n eef-r*'* CB> f M r*i i'e*'. f / ?v*m? H * (oclKi<i) < c/ccrtrOf Of C C . tf IAS '/ b *Oo tin . So* **.1 *1 J p of" "6 *t /*. U. o ci ft11 V Vp . r.vr y//fr '**'* &07 2-** Si'-? 3 ..'/ 7,7/ />"6 ' 396871 --.41>,1 ~. 50983 DOW CHEMICAL U.S.A. TEXAS DIVISION PREEPORT, TEXAS 773A1 ENVIRONMENTAL HEALTH REPORT c C c c Concentrations of asbestos in the general atmosphere in F-4 furnace, with no activity, was found to be below the Federal Regulation. The current regulations governing permissible exposures to asbestos are based upon the possibility of contraction of asbestosis. Asbestos fibers, however, have also been shown to be carcinogenic. No dose/disease relation ship has been established, so efforts must be made to reduce and eliminate, if possible, the workers exposures. Due to the low levels obtained, it is permissible to enter the furnace without a dust respirator. However, when work is to be done on the insulation, dust respirators are required. Distribution Frank Travis File AN OPERATING UNIT CP the OOW CHEMICAL. COMPANY 396872 b I U U I tf 4 0 0 *5lS>" ENVIRONMENTAL SURVEY SAMPLE RECORD date: IUILOINQ NO. R-+9O0 PRO CCS* LHP IAMPUM4 UCTHOO tuacaviwa As 4 t rtTai TYRCOP C OUlPMIN T aCMMANSKI A APLOWiINC<* CATOa ____ IQ 1AMNLIN4 NATE 2& MNO**Oi1N. ^ !A~ VILOCI TY T ^ j / /<. F~ Fv * * 9 c. <. , AJ & A* c^6 ' ^ .~z > * -6~h T (MP. "V k' i/J Sompio CoAtoio No. Of No. 8-* too SAMPLE DESCRIPTION A **f * , -c Stwt TIME Sii ?>M Lii A ScmpU Volumo AAofyaia Cor ire 2.0*+ 7-2. 40 396$373 > 2.. I -l os- July 10, 1973 Glenn A. Schankle Oyster Creek Your five asbestos samples from the Chlor-Alkall Plant, Oyster Creek Division,- were analyzed for fiber concentra-- tion using the standard procedure. The Midland Division Analytical Laboratory counted the fibers greater than five microns in length (with at least a 3:1 length to diameter ratio)- using phase contrast microscopy at ~450x magnification. ... -t,-. Assuming an air sample rate of 5 CFB (2.36 liters/rain.), 1 the airborne concentration of asbestos fibers would be as follows: . Sample Sample Volume (liters) Piber Concentration (fibers/ml)______ I IX III IV V 59.0 153.4 177.0 141.6 35.4 2.80 3.83 0.20 0.08 0.62 You should calibrate the actual air sample rate periodi cally for your records and make sure the pump is working properly. The calibration should be done by leaving the face cap on the filter holder and connecting the nozzle to a dry tes;t meter. If you have the small MSA portable pump (Approval #2P-2004), the pump should be recharged after three hours use. 396874 06*1'! I 001S Glenn A. Sch? '*le 2 July 10, 1973 The Dow Industrial Hygiene Standard for asbestos is 2 fibers/tal based on an eight-hour day, 40 hours a, week time-weighted average. If the fiber concentration exceeds 10 fibers/ml during any 15-minute period, respiratory pro tection is required until the appropriate engineering controls can be employed. I would recommend a closer look at the areas or operations included in sample II. The concentration of 3.8 fibers/ral over a 65-minute period suggests that the allowable ceiling concentration may have been exceeded. You should also plan to collect enough samples so that the time-weighted average exposure can be determined for each of the men who handle asbestos. I have tentative plans to be in Freeport in a few weeks, so maybe we can get together and discuss your asbestos sampling program. In the meantime, if you have any questions, give me a call. Best regards. Chemical Biology Research 1701 Building jmd 396875