Document GmJjJgOMYVwp6RmryzdyZMKOv

FILE NAME Packings and Gaskets PAG DATE 1973 Apr 24 DOC PAG064 DOCUMENT DESCRIPTION Report - Dow Chemical - Atmospheric Concentration of Asbestos Fibers While Cutting Gaskets SECTION 9 DOW CHEMICAL / ATMOSPHERIC CONCENTRATION OF ASBESTOS FIBERS WHILE CUTTING GASKETS 4/24/73 ee oe U.S.A. -- File <fijeeye~ DOW CHEMICAL U.S.A. 50983 TEXAS DIVISION ENVIRONMENTAL HEALTH REPORT | ATMOSPHERIC CONCENTRATION OF ASBESTOS ; FIBERS WHILE CUTTING GASKETS FILE NO A24-173 DATE April 1973 -AUTHOR L. Silverthorne a Summary 4/24/755 Concentrations of asbestos the general atmosphere 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 MIVUL Distribution Billy Parrack . File 2431 AN OPERATING UNIT OF THE DOW CHEMICAL COMPANY m File No. A24-173 -2- At the request of supervision Industrial Hygiene was asked to evaluate the Asbestos hazard presented by the cutting of gaskers 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 cc b Breathing zone of man cleaning up area with broom -- Note Area has not been cleaned up for up 2,04 cc several days c At top of stairway 15 from cutting table cc ST0652937 . d - Breathing zone of man cleaning table 3.08 cc with broom and picking up material off floor with a scoop NOTE a were taken when the area had not been cleaned for several days e Breathing zone of man doing the cutting .78 cc f At top of stairs 15 from cutting table 0 cc g In middle of shop downstairs during cutting- .12 cc h Breathing zone of man doing cutting .90 cc NOTE e thru h were taken after the upstairs area had been cleaned up regulations ' Current government allow no more than an 8 hour time at weighted average concentration of 5 cc The regulation also - states that no employee shall be exposed any time to airborne concentrations of asbestos fibers in excess of 10 fibers ' 3 The current regulations governing permissible exposure to Hasbestos are based upon the possibility of contraction of asbestosis Asbestos fibers however have also been shown to be carcinogenic No disease relationship has been established so efforts must be made to reduce and eliminate if possible the workers , exposures File No. A24-173 mn -3- 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 Lo DISCUSSION ST0652938 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 the atmosphere the purpose of which is to prevent asbestos workers from contracting asbestosis The current standard is 5 fibers as recognized by the Federal Government However over the last few years respirable asbestos fibers have been recognized as being carcinogenic A 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 done most desireably by reducing the exposure to the workeransd 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 10 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 File No. A24-173 oo , -4- DISCUSSION continued It should be remembered that the numbers giv ae s tn he 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 ST065293 bbs 4-19-73 No. | File A24-173 ASBESTOS IN ATMOSPHERE DURING CUTTING OF ASBESTOS GASKETS Filter Factor = 154 SAMPLE TIME min _RATE M TOTAL VOLUME L Hamt9 3 Hamt9 2 2.57 ~ 2.69 7.71 5.38 Hamt9 3 2.69 Hamt9 3 2.57 10 1 min 7.71 ' 10 sec 2.69 8838 1 min 10 sec 2.57 2.99 8838 3 a 2.57 .7.71 8838 3 2.69 8838 -0- --^-- Concentration = Total Fibers Total Volume -0- * Fibers * CC ST0652940 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 , ro. (x70e 126 ENVIRONMENTAL BUILDING BUILDING NO Cutting | MATERI ONACL HEMICAL SURVEY SAMPLE RECORD Asbestos, Cuskets SAMPLING METHOD METHOD DATE 3-29-73 3-29-73 3-29-73 3-29-73 SUPCAVIDDA Harold Hewett Hewett Millivera Millivera MEDUN MSA Pump clean Floor had been top is clean 10 swept the . : day | NE Papit beforms beforms Area and tabl Liters + Semple Semple Centein | Ne 10m 10m SAMPLE DESCRIPTION furio | Bridges on Herbert cutting cutting WearingWearing respirativ gaskets Start Stop Sempla Analysia 1:10 3.13 16 | Pump At top of stairs during cutting cutting . 20 t 1:10 2,99 9 Pump Inmiddle middle Jaskets Jaskets of shop - during Levene! On Layd Trohan during cutting 40 - of of gaskets gaskets 50 . Sample Blank Blank min 7,77,171 | 2 Bumin 8,078,078,07 48 ST0652941 ne se ert teh ter rena a <i ENVIRONMENTAL SURVEY SAMPLE RECORD DATE 3-31-73 3-31-73 3-31-73 BUILDING BUILDING NO 4-1876 PROCESS SittingSiting Sitting MATERIAL ON CHEM CAN a Asbestos Asbestos ; 7 F COUPMENT M & A put P ~ free free a cutting cutting is ; . asbestos gaskets asbestos gaskets SAMPLINGSAMPLING METHOD Air FLORINDICATOR FLORINDICATOR 10 SAMPLING RATE : , -SUPERVISOK -SUPERVISOK -SUPERVISOK Harold : Heuth Heuth TRA MEDIUMP MEDIUP M ING 47 mm fillw fillw |TIMO VELOCITY a _ . TE Sultan The upstairs upstairs 14 1876 1876 in neoprene neoprene cork watarial su North side it The fle has not been swept for several days Tatal , Liters Fiber Fiber SAMPLE DESCRIPTION Somple Contain j Pump Mr. Gaminage Gaminage Gaminage Gaminage ; cutting as bestos bestos TIME Sample | Analysis 15M 8:18 344 7571,264 751,264 7571,264 2 mpbroom Pomp . In breathing zone Not on Mr. Gamways Gamways 2 3 At top of stairway doring top ccuuttttiinngg f asbestos neoton cork materiel gaskets area with Pomp brown Mr. GammageGamage cleaning up table and # 1 broown Sweeing top of floor up 8:15 5:18 3 3 8.07 288 8.25 8.28 3. 7,71 7,71 " 156 . 370652942 370652942 370652942 370652942 370652942 370652942 370652942 370652942 370652942 ed