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I. INTRODUCTION ( '# "4 kCitY V' ^ NOTE: TWiS DOCUME^^t^l A survey to determine the ad > system and associated dust collection equipment to control air- *\-f iwfy\' borne dust was performed in the production area of the Pittsburgh- 3$$! Corning Tyler, Texas olant on May 7, 1969 by Dr. Morton Corn. Dr. ' Corn was accompanied and assisted by Mr. John L. Hyde, of the En- ^ gineering Section, Pittsburgh-Corning Research Center, 800 Presque r * ^ ^I'llT'll Isle Drive, Pittsburgh, Pennsylvania 15239. The survey was per- , '? * formed at the request of Mr. Byrl M. Stout, Vice President of Manu;- facturing, Pittsburgh-Corning Corporation. The request was mad on April 28, 1969 at the Pittsburgh-Corning Research Center during' a meeting called to discuss the enclosed citation of the Tyler plant by the Department of Labor (see Appendix A). The survey was concentrated exclusively on assessment of hygienic risk to --------------------------- ------- """ ** airborne amosite asbestos dust and evaluation of plant facilities 1 >;* to reduce thi risk. l . *? J . , 'V During the period of the survey outdoor weather conditions were ,. clear, sunny and warm, with temperatures in the 70-80F rang . .. 1. Humidity was high. (Relative humidity in plant approximately /v` The author is unaware of any special precautions taken to en- ` sure that the ventilation system was operating in anything but . "AVAt ".'lov 1 the "normal" mode during this survey. Therefore, results of mea . vr.1? '."-l-'jjwi surements made in this survey must be considered representative m of conditions in the plant during summer months when doors and *' . . Wr-.J* , * 1 -W-l\ windows are open. In general, winter conditbns impose more !. --------------- 6-VS'W'i #i -1 ,W*t Measured at 11:45 AM in plant. !&; / j BB 0008400_r --1 --^ -- "* "" "" *&| w.. t >- 1 * | u * l \ '. \ i*; 2- . . * 4.t.`..- . -- F * .It- .: / . - *' -. ..V2g *,. ** * :'rj&$2s' stringent requirements on plant dust control systems because win-.'VrfjjJJt '"vv $?$ dows and doors are closed to preserve heat. There is no benefit > -'tit'?*; v: of "dilution ventilation" from outdoor air. with the same facil- ities for dust removal by a ventilation system, in-plant dust iIn *-*?9 air concentrations during winter months will usually exceed those 'Ax\-r 'W'-ksli* present during summer months. : ' '; * ' u" * -v*** rv .-.i' ? v ; w,w VJiijft ** 1 't*.i 4 f'V'f1''' ` , ,, Vv,*-..s . * . ; i* i, ^ # , '* 1 ` . ^ < ` ' '.-'Vi: .. ft *> -/ vftfSdRT Si*. V . *.. ' , . * ; l* . ' r\ i , * . / ** ( !, V fifcj * :v -km , fi - ** * '-* V r> -U te* \\W ' , . ,5-`I :*5; *<-*. GC- / | BB 0008401 | ________ *7*"V; ` - im,TxP "l V ' ' VI. .>'!* , jv."- 'i* ': * ^WwSjL - ; 'J Tv* j- ?* ,-WtT! f- v y ;. ~g> ' * ; m| t L r3Ns,OihTTEr: T%H, IS DOCUMEf/tgiij^S II. SUMMARY AND RECOMMENDATIONS NOT COME FROM PPG FJE& An industrial hygiene and ventilation survey of this plant -'''Qhte performed on May 7, 1969 suggests that asbestos fiber concentrations are high in wbrker breathing zones (Builder and Feeder Op^ ' T&A r'\. C erators) and at breathing level in certain other plant locations. ...,v There are no hygienic guidelines for concentration of Amosite fibers in air and the judgment of excessive dustiness in this . ? plant is referred to guidelines for Chrysotile dust. Utilization L.,j of hygienic guidelines for Chrysotile asbestos concentration in 1 air for Amosite asbestos fibers in air is an accepted procedur '`'"VitfjfUlSi in the U. S. at this time. The finding of excessive dustiness at "spot" sampling locations in the plant is consistent' with sur-' *'' > vey measurements which revealed inadequate quantities of air at local exhaust .hoods. Insufficient air at local sites of dust *' " ' emission was reflected m low air velocities at hood faces and "' t.-W* low air conveying velocities in branch lines and ducts. The ven- : V tilation system was estimated for Builder and Feeder areas to move ` approximately one sixth of the air required to ventilate these . AY* processes. ..vAacVr ~ ' ' 'Hm In addition to the inadequacies of the ventilation system and yip^js the resultant excessive dustiness, it was found that general house- ^'V/------------------------------- Keeping is poor m the plant. Also, during the entire day of the survey not one employee in the production area was observed to wear a respirator. " & In the opinion of the author, this short survey strongly suggests that employees at this plant are being exposed, on a ______ ir6- T~bb~ooo8o2_1 , ,y(Y^ i * 1 V f?- ' -V r ".. , fi .< * i* * / ' ' " . *' r':-.. - iy1 j* :, .. .l***Sj ,,. ' ' - IV f. * daily basis, to excessive concentrations of Amosite asbestos dust. 'V*fVi<fchl It is recommended that efforts be immediately focussed on design of a complete ventilation and dust collection system at this plant. The system is rudimentary in concept and is underdesigned. ------- - Efforts to "doctor up" this system would probably lead to a less * than satisfactory system and would involve expenditures in time and equipment equivalent to those associated with design of a new 4.t` ,u., system. ^\rv . > fcs'.&V a*.?.'* r\Cvi^v' t\v$> ` \\tf 0 k ' ^ 1 ' i, L, ii f\ . V <S.;>;' y*-w vf . '>:. "V 'r* . - j ,^<7i *. .f-pvH.vJ-#vrt*.iy<v?r3. . ft* . >ti' ! 4f . : <11 . I / I -- B-B------------Q---0--0--8--4--03~7* * ^ .77 , ; % ft j* *w kI V:* Mf-' l ' . iVti* k:j?| 'i'nMSS III. THRESHOLD LIMIT VALUE OP ASBESTUS'TXitwi- I nUIW t't'U fltES "The threshold limit values refer to airborne concentrations of substances and represent conditions under which it is believed ' that nearly all workers may be repeatedly exposed, day after day, -C-'. without adverse effect. Because of wide variation in individual_r* '>*# susceptibility exposures of an occasional individual at or ven. below the threshold limit may not prevent discomfort, aggravation of a pre-existing condition, or occupational illness. "Threshold limits should be used as guides in the control"of health hazards and should not be regarded as fine lines between-* r safe and dangerous conditions."* .yJ-jiii!' The American Conference of Governmental Industrial"Hygienists^ had, in 1967, a T.L.V. for asbestos of 5 million particles per ' '' '' cubic foot, determined by impinger sampling and counting by , * light-field techniques. In a considered revision (1968) ,. the Con- ference endorsed the retention of this T.L.V. for "most forms of asbestos". However, for crocidolite, because of the production 1 * of mesotheliomas, it was recommended that workers be equipped with|9^^ air-supplied helmets because "no safe limit can be established for this form of asbestos at this time." - ' Vy ` * - . JjfiT The British Occupational'Hygiene society recently issued hy-'i^'-i':' . gienic standards for chrysotile asbestos dust.** The standards ':S\vV are based on the objective that the risk of contracting asbestos '#X:- Extracted from the Preface, Threshold Limit Values for 1968. . American Conference of Governmental Industrial Hygienists, 1014 !%SV Broadway, Cincinnati, Ohio 45202. ** Ann. Occup. Hyq. 11, .47-69 (1968). , .. X A it*'- 1 : ' *'* ' 1 ' * '''ffW?' ' /' / CrC^xJ `KhV> vy/^t;.,: - |VS: 7"Bb"0009404 ---------------------- be reduced to 1 per cent of those who have a lifetime's exposure to the dust. By "asbestosis" the committee meant the earliest / " demonstrable effects on the lung due to asbestos. These standards are cited here because they are more stringent than the U. S. guideline referred to above. The exposure guidelines are: 1 NOTE: THIS D0CU*)l^8 TABLE mwMV'pmtLemBRITISH HYGIENIC GUIDELINES F' ' .r *- DUST CATEGORY CONCENTRATION AVERAGED OVER 3 MONTHS, Fibers/cm3 MPPCF* \ Negligible 0 - 0.4 0.011 Low 0.5 - 1.9 0.014 - 0.054 Medium High 2.0 - 10 Over 10 0.054 - 0.28 Over .0.28 . .. 'V. ,7: 4' r'S- i ' ' ' 1* %I&: The concentrations refer to fibers greater than 5 microns in length'.MM as determined by the membrane filter method. ------------------------------ -------------- ---------------------------------------------The problem faced today with respect to Amosite asbestos is that there simply is insufficient data for dosage-response pre- ; '* ' diction of exposed populations.** The guidelines for Chrysotile : will undoubtedly continue to be the threshold limit value guide-- line for exposure to other forms of asbestos dust for years to come. ` 1 " In a survey of dust concentrations in the Unibestos facility, Port Allegheny Plant of Pittsburgh-Corning, simultaneous impinger ' ^ -LJ#**** Million particles per cubic foot (as fibers) ** Stokinger, H. E. "Development of TLV's for Fibrous Materials." 7* . .,r\r Paper presented at Special Session on Fibers, Annual Meeting ; VjiV.* of American Industrial Hygiene Association, Denver, Colorado. - *y ! / *rJrr1-b^S00S08M40T5_ii :: i- 'll.'. and membrane filter sampling was performed. The conversion of values obtained by one method to those of the other method was not possible. At each location, the numbers of the fibers and -. particles varied. The impinger method is based on particles while the membrane filter method assesses only fibers. For the 4 ---------------------------------- ------------------------------ ------------------------ purposes of this preliminary survey, either method would yield ' ' * V'l?# / hv i'k data suggesting that airborne dust concentrations were acceptable or unacceptable. Therefore, the membrane filter technique was used and the British guideline is applicable (Table I)' vA>$?lp v, -v.;, -ii-gfc., ;r-/y Cv^ ' .. - <<*** j * <$y> . ,v. -v , vv^iv \o\ I' ,, _ -i'vfr ' "*?'.* vVn$^ <' ;*/.* ' '., '?ii*v-iX&; I * i'it &xI -Si# u-lir/M/j .`ySUHtf. v ,; : v{;> ' *?* **? wf> kk" IS.,** '*. II <. / T__bb^ooo3^06"J, ;;v'-'J&ij . " ! *Vi?.; r w I `I rr 'sJ - s-t 8 :,7 \f'f-: HVyVJ v'*'?* **;?V' 1V:,f$cmvUSfkJi?V&vii IV. DESCRIPTION OF SAMPLING AND ANALYTICAL METHODS NGTfcTHisuuwi^r-- t^ A. Assessment of Airborne Dust NU iMEFROMfPGf'^g Samples were obtained at eith r breathing zones as vj'vj&i they performed theifr routine tasks, or at breathing level to re- .iotgS present "background air". Samples were obtained during a five or Vl(fc5,ii i-Jv ten minute period^at a flow rate of 21 1pm by-utilizing a vacuum pump in conjunction with a filter holder and sample filter. The system was precalibrated in terms of pump inlet pressure and air . flow with all sampling line components, including filter;'in'plac* ... -`Mm A membrane filter (Type HA Millipore) was used to obtain : samples for microscopic evaluation of fiber and dust particle ;- concentrations. This paper is composed of pores 0.45 microns V it in size and has been shown to retain, with 100% efficiency,* par- tides down to 0.05 micron diameter. 1 fcV The filter was first visually examined to detect any loose : ~' dust or uneven dust deposition. In the few cases where the fil,,r* Vi -j. ter deposit did not pass this examination, it was necessary to re- suspend the collected dust in distilled water and refilter this' suspension on VF grade Millipore filter to assure an even dust distribution over the entire filter area. A pie shaped segment 1 of the filter v/as then placed on a microscope slid$ and rendered m* I completely transparent with Cargille certified index of refraction * >. , 1. , m* 'y<, *-i liquids. Cargille liciuid of index of refraction 1.500 was usually ; most suitable. The counting of the dust particles and the count- mg and sizing of asbestos fibers was performed with the aid of a ------------------------- /'%$:! | fiB 0U0U0UO84H0US7 | r Megaw, W. J. and Wiffen, R. D. : Int. J. Air Water Poll . 1, 501 (1963). --------------------------- ,-r.. Zeiss Photomicroscope using Phase Contrast Illumination. ;, The ob- im iective lens was a Zeiss Neofluor Ph 63x with a numerical aperture : J of 0.90. The eyepiece had a magnification of 20x and contained a : calibrated Porton graticule. The optovar feature.of. the Zeiss . ^ l. scope contributed to the total magnification of 2016x. Resolution was approximately 0.35 microns. Partic^^d^j^rg^ microns could be detected. NOT COME FROM PPG In the evaluation procedure# all particles and fibers in the Porton field of view were counted and the fibers were, grouped . - iV rMjtiVk' by fiber length into three categories (less than five microns# -------------------------- --------------------------------- --------------- -------------------- v five to ten microns# and larger than ten microns). This procedure was repeated for a number of randomly selected fields on the face" , ..A'ffll of the filter. Because only a portion of the total filter area , h***.-^ ' .. ^|` fa** was evaluated, by this method# it was necessary to correct the count by the ratio of the total filter area to the evaluated ar The resultant particle or fiber number was divided by the volume -' of the air sample to obtain dust or fiber concentration expressed ' , .------------------ - as millions of particles per cubic foot (MPPCF). : . ** * The statistical reliability of the evaluation was expressed i ?\* .-s'* as the standard deviation, calculated as N 1/2 where N is.the ^ .i i particle or fiber count. * ' ;>&- The procedure outlined follows# in its essential points# that 'Jl&i recommended by J. r. Lynch and H. E. Ayer in their article "Mea- : surement of Asbestos Exposure" which appeared in the Journal of *\ *ayj<V^ Occupational Medicine, Volume 10, January# 1968. ^ * <v-, CHr'-f*/ ' ';* * 1 . : . V iV%v / i-BB-OOQMOB i; O' 10 + B. Measurement of Air Velocities at Hoods ?;' :.' ?'--?4 "V"- -'V^ A calibrated velometer was used to measure face velocit-.**$$$; ies of hoods and room air velocities.* C. Air Velocit*ies in Ventilation Ducts . .. . * >* * '**HiV.r1 A standard 1/4" dameter pitot tube was used in conjunct ->$p ion with a Dwyer 1:10 inclined manometer to determine velocity , pressures in ducts. Ten point traverses were taken in larger , ducts (>6" diameter); centerline readings only were obtained in Ye, yjL&lj-i.-k fcv smaller ducts. All measurements are considered to be approximate*^. (estimated reliability + 10%) because of the conditions imposed by the system. For example, there were few locations where measure- ments could be made 10 diameters from entries or elbows.7? Also,' the standard pitot tube should not be used in lines smaller than ' 8" diameter. .However, the reliability of measurements achieved' . is perfectly adequate for a preliminary survey of the type under-' taken here. ' 4-''*- { `\r-rn NOT GOME FROM . :..'ri'--.'i--rrptrySfzal ` <i?\, V-,-' ; ,</ 2 BB 0008409 J t. , ` ' \\ l r * ; V'* I : 4'4 V'38S !/*>.') ' 1 ` ' ''f-V'P'v ' ' -.'.m Alnor Velometer, Illinois Testing Laboratory, Chicago, IllinoiJs / : i.' 4 5'*j*.t*-st0l.' I w7 I ', >f' 7h. * . IV - 'zm-5$S f' ,f* * . * ?>!, V. RESULTS AND DISCUSSION i M V ! 4 : i ;' \J V ij A. Airborne Dust concentrations NOT COME FROM PPG FILES^lsI Measured concentrations of dust particles and asbestos ::-V$ fibers are summarized in Table 2. In, order ta facilitate com *>. >5V parison with the guidelines from Table 1, the last two columns (5 and 6} of Table 2 for fiber concentrations have been add d * -j`: *#> vrm , " V* to yield Column 7, which should be compared with Column 3 of . Table 1. On this basis, operators at the feeders are receiving .. High exposures. Builder operators are also receiving High xpos-'i^^^gj 1' * ures. Although much dust is present at the cutting operation the;VJ:i ---------------------------------------------------------------------------------- ---- ------------------------------ single sample obtained suggests that particles and not fibers ar 1______________ _________________________________________ - the major contributors to the dispersion. Table 2 suggests that- ---- ------------------------- ----- ------------------ - ' _ ;'1'- outdoor air is Negligible in terms of fiber content, as is the I dust collector effluent. However, the aisle of the warehouse op- ---------------------------- - -'%&f posite the Feeders is High, suggesting the large zone of influence of the dust sources in the Feeder areas. It cannot be too strongly tJt >; ;i?-v I stressed that these are "spot" samples and must be viewed as sug- gestive results only. However, they do convey a picture of dust exposures in Feeder and Builder areas, as well as in adjacent-, m ^________________________________ :* AVv zones. The author must state, based on previous experience, that ` dust concentrations in plant air would almost certainly increase %}'$) during winter months. B. Local Exhaust Hood Face Velocities ---- , > -J r'-H J BB 0008410 | ------------j There are design guidelines for face velocities of air at- local exhaust hoods.* In general, a face velocity ojlf 1iu0u0 fifpcmwi ixsa . -r/'it See Chapter 5, Industrial Ventilation, 10th Ed. American Con-''V'-V ference of Governmental Industrial Hygienists, 1014 Broadway, Cincinnati, Ohio. _ Date and Time of Sample TABLE 2 \0^ {' ASBESTOS FIBER CONCENTRATIONS AT SELECTED PLANT LOCATIONS % Dust Particle or Fiber Counts, Expressed as Millions of Particles Per Cubic Foot + Standard Deviation Total Fibers (Cols. Description of Sampling Site Particles <5 u 5-10 u >10 u '5 + 6) 5/7 2:30 PM- Breathing zone of Feeder Oper 12.3+0.6 3.60+0.28 0.64+0.12 0.14+0.04 2:35 PM ator, Lines 1 and 2 during / sweeping, feeding. (Note: cooling fan at dust collector on.) 5/7 2:36 PM- Breathing level in Walkway ad 10.5+0.5 ,, 3.40+0.19 0.34+0.06 0.14+0.04 2:46 PM jacent to Feeder No. 3. 5/7 2:50 PM- Effluent from Dust Collector 2.9fo72j) 0.71+0.09 0.06+0.03 0.02+0.02 Bags approx. 1-" from Bag. Dust- collector for Lines 1 and 2. 5/7 3:05 PM- Outdoor air sample at breath-( 1.5+0.2"', 0.16+0.04 0.03+0.02 0.05+0.02 3:15 PM ing level on loading dock near _ ~ Oil House. 5/7 3:15 PM^3:25 PM Breathing level in aisle, Unibestos Warehouse opposite Feeder Lines 1 and 2. 35.0+1.7 j 1.26+0.12 0.18+0.03 0.10+0.02 5/7 3:30 PM3:40 PM \z\ ii a il !| 5/ I 3:45 PM|*{ 3:56 PM j:. 1- ` 'V 3reathing zone of Builder Operator, Line No. 3 (3/4 x 1 Unibestos). Cycle of load ing, building, spraying, etc. Note: Fans on over Lines 2 and 3. Breathing zone of Builder Op erator, Line No. 3. Cycle of. loading, building, spraying, etc. ' ; 3.2+0.2 1.48+0.09 0.18+0.03 0.10+0.02 " N 3TE: THIS )0CUMEL TDID - N 3T CQMEF ROM PPG FILES 12.5+0.6 4.02+0.20 0.20+0.04 0.21+0.05 ,,i '- - r- TLS *J' \ n- 0.92 0.48 0.08 0.08 0.28 0.28 vf 0.41 ,* + ` * t`X1* ** -vf* . \< u 14 v- 1 `if " -i' >,Tiw"'L>,vfi `'r-'tpfil " '.' ` i'i'-' ti'Wsm recommended for control of fume and vapors, while higher veloci- , I*1- '* ties are not uncommon for control of materials emitted with great '- `vify, force. At the Port Allegheny Plant, Mr. John llyde, of Pittsburgh- Corning, and the author are designing for 200 fpm face velocity at ;:^.,V, hoods which interface with plant air: internal process hnoodas are designed for 100 fpm. fNOTE: TH` IS DOCUMENT D Table 3 is a summary of measured air vdiocTtie3a'U6eje< hoods in the Tyler Plant. With the exceptions of the Builder V hoods and the Scrap Grinder hood, face velocities at hoods "are/1 v ' inadequate. Smoke tube tests performed at each hood offered visu- sVijs i al confirmation of this conclusion based on velocity measurements. Although the hood on the Intermediate Saw was satisfactory'/ it *-? ' would not be so if two or more saws were used simultaneously. C. Air Flow Associated with Local Exhaust Hoods and Dust > Collectors ' TfiaL Figure 1 is a line diagram of the ventilation ducts in the 'fix# , . . .,,*$ Feeder and Builder Areas. The duct locations for Pitot tube tra- I verses are denoted by numbers. Table 4 is a summary of volum of i*Ai- .w 1f air flowing at these points as determined on the day of this survey.,-.^ v-if1 The values listed in Table 4 are probably overestimates because cer-^S? id*1 tain of the ducts were partially clogged with settled fibers. All- i data and calculations for the Table 4 summary are included in Ap- pendix B. . ; , "'JV-.V'-' Table 4 and data in Appendix B indicate the following: _ . . . - Vv 1. Air is very poorly distributed in the ventilation system. ;i.V/iyi As an example, hoods 2, 3 and 4 for similar operations were alio- >T cated 63, 391 and 202 cfm respectively. // GrG* .ltTv!- - ------------------------------------------------.--------------------- J_BB 000341 3 | ' ; , C o w* .I 15 TABLE 3 UNIBESTOS LINES: SUMMARY OF HOOD AIR VELOCITIES Location Site of Measurement* and Average Air _________ Velocity/ fpm**____________ Line No. 1 40" Fiber Feeder* Line No. 1 30" Fiber Feeder* Left Side Top 0 Middle 0' Bottom , v. 0 1 * Center Top 50 Bottom H 50 Right Side Top . ' .0 Bottom 0^ Note: Smoke tube test revealed poor control. v < Left Side Center Right Side Top Bottom Top Bottom Top Bottom 20 20-36Q0 V:i -V ' 'r 60 . 60 so Line No. 1 30" Fiber Feeder+ Line No. 1 40" Fiber Feeder Line No. 2 40" Fiber Feeder (Note: Approx. 75% of hood face blocked by fiber) Left Side Center Right Side Left Side Center Right Side Left Side Center Right Side -- TOp ;l , Middle ;. Bottom O ( `VTop O: ' -'-J* '1, Middle > '* Bottom uj Cp: />: Top Middle QQ- Top O S Middle O Bottom tn - Top ---- UJ Middle Bottom Top Middle Bottom s-- o ili ^ ; s--. oo Top Middle Bottom Top Top , Bottom . i 0& .. o t>'.L. 20 . 0-10 0-10 /V 20-30 . 30 o ;; ` o ,, j_V\ o ;; r 10 10-30 *? 10-30 o ' . 20 20 k 50-100 `V 75-100 75-100 30-40 jt- 30 . 50 Room air in vicinity of feeders measured to be 30-40 fpm. South `/-J. to North (fans off). Room air in vicinity of feeders measured to be 300 fpm, South to North (fans on). T^sFoooiairT1 (! 16 ' V > .\' Vv VV -:\ . : sty ,- v />Wjr TABLE 3 (continued) Line No. 2 Line No. 2 30" Fiber Feeder 30" Scrap Feeder . Stand by (not in use) Left Side Center Right Side Left Side Center Right Side Top Middle Bottom Top Middle Bottom Top Middle Bottom Top Bottom Top Middle Bottom Top Bottom 10-50 30 ); < '20 - .'.f *' - 20 `' 40 : :;* -- U4 30 T - 0 : M ip % H- (_l_ 31 2i 1i r'znr 40 ! : r$4 20 v^; 75-100 \a;\ *2 Moo , v, g'& ; 100 ::r 100 cm. OS-8o' 75-100 125 TP S2-S-' 75-100 ;t# Line No. 3 20" Scrap Feeder Left Side Right Side Top Bottom Top Bottom -j- ^ H---GX QJ r"7 r~r d> 0 -0 i- 20-30' .0 VS 30-40 ;^} Builder Hoods Line No. 2 Line No. 3 Line No. 1 125-150 ':f 150\* 'If, ' k<M Invalid measurements be- cause instrument could . not be properly placed. Smoke tube revealed good Mu*r Scrap Grinder Hood Left Side control. Top * 75-100 * Middle 100-150 Bottom 150 *& . Center Top Middle Bottom ` 75 . 75-100 100 f & Saw Area: Right Side Top Middle Bottom Intermediate Saw+ 11 , * 50-75 50-75 . 50-75 ''V iVC iv!i &V'{ 200-300 Large Rip Saw Off. Cr^r'l*^ / iJ-} w )$ All measurements in vertical plane at hood face, unless otherwiseT;,'Vf specified. ** Feet per minute. ______________ 2_B 0S,7:i -------- -------- *.*,*' I'r V.~. ir i -rj" - ' 1 - r> , r LINE 3 . . r .. * r Sty*! 3 :-* ~t 'c BUILDERS --Y h* ;t w r . * C. * M*a 4 i,-. . . -r .* t.v c .. r. ^ ^ /j - - - -* >- i * * . " 1 * 1 ' -i . :,4i ;_;]i .: 'H, i-1** ; - -* *j- ;,.-.*.*.* I rrfcr? -V*.-tW-'?r.u^r.s;*Lv*- ;::^Tj.' :: ~ ! :*; 3> ir . i .L- :f ' .?i . ; t -** 5; .T-; t--i , . .m '1 18 4 *4 :1i - *- . 1 ..f ,>`*.*V" *** t*4 u^S}4 . 1 *WJU . v' 'V-# - * 'i-M-mljlS r, * `v\; -V;>{ f-nfinfi - mm TABLE 4 SUMMARY OF VOLUMETRIC AIR FLOWRATES IN DUCTS IN FEEDER AND BUILDER AREAS :. . `:pm i\ *> J _? fci i * ^. '4lr Duct Number (Figure 4) Feeder Area: 1 2 3 4 5 6 7, Builder .Area: 8 9 Air Flow, Cubic Feet Per Minute ' 2,769 63 . 391 202 1,940 183 4e . * ,*., * i '+ *, ' -. * - /*- x 4 'J.!t* \ t ` i > .. i 877 . , * >". i ' 1,724 v: 810 v ' ' 1' . 'Jp' ` . ' Wj?W X-- :v ; " . . :* J'! NOTE: THIS DOCUMEflf^T^P NOT COME FROM PPG FILES; f? \ '*'rW; -iHi *. r . i / ^ ''Wpl ` ', / | B2B2.20202028241171 I1 ti'/ Z'1 ; '**r*?* '/M i* 19 2. Conveying velocities within ducts are generally vesry low - V*,. for handling asbestos dust. A minimum design velocity of 4000 1 <. *' 4* i`rwS, fpm is being used for the new ventilation system.* Duct 7 (Scrap - Grinder Hood) and the 10" diameter duct into the Block Dust Col- ' f * * V ? lector were the only ducts with adequate air velocities for con- veying asbestos dust. NOTE* THIS D0CUM^T'.'.P{&.^3^^ 3. Total air volume for the Bui^^ij O0f4eFHO^eP1PQsF^lsES-. low (2769 + 1724 + 877 cfm) . Estimates for Port Allegheny place ... . i ' *- r \ tfh.' the air requirements for adequate control for three lines at - ap- proximately 6.5x times this amount of air. - `*'V '-r In summary, as judged by three different parameters,. i.e. ^ H .v - dust concentrations, face velocities at hoods, and duct_air^_y umes, the ventilation system, and hence dust_control at this * plant, are unsatisfactory. ______________________________ D. General Housekeeping /, In general, housekeeping is judged to be poor at this *,, plant. Appendix C is a selection of photographs taken during ' [ this survey. Asbestos dust is on all surfaces as well' as/in * the''^^^^ air. It was noted that with the exception of Mr. Hyde and the !-y, author not a single person in the plant wore a respirator. It can only be concluded that Amosite fiber at 'this plant is not .. being handled with the care and respect that any substance with , this toxic potential deserves. The practice of exhausting bag dust collectors to plant air* V would not be permitted in the states of Pennsylvania and New&>&, t WB. ,. York. Air cannot be recirculated when toxic substances are v' i / Port Allegheny Plant. a w *n ; ' i ' ( *-,`h ; \ ` yfr; 20 -/-V involved. ' \- ' r'. .r In the case of nuisance substances, recirculation is permitted if the recirculated air contains the toxic agent in ``O concentrations less than 20% of the Threshold Limit Value. . - ' \ fr* . " ; ... 0 co UJ '' P' l!* * '*,' p U- m * -J CD ! Q- rvrv;v .) 5 *; O -3 Q= > - UJ -o Io `V;. ; ' ` .7 V$X-+!`Z'' C'mSS ' ' J* -S *'* . ' i - V *. ; "v : 'Jfjlji. "" i 1. r O .- ...\V -V -!.Jy .^S 2T . - . -V.v;-/ 1. , . - i> ' , *. . -..*1 J*` .* ... : ,f \*r >* `'Hf >?f ; ggss ' -mV GoG IGVG.N |_BB 0008419 | , : ' .* 'viV>`*: >r ' i.' 74.t , 'V**- I -V,'V V, \MV. *1v.5, / ''0.1 i*.. t 7- i * *. \_r * - *f It y i'\ ' 21; ;1 ; ' VI. ACKNOWLEDGEMENT The author wishes to express his appreciation to Mr. John L. * Hyde, of Pittsburgh Corning Corporation. Mr. Hyde provided in- valuable assistance'with survey measurements. 4 * , ' . f-Vn ' - i'.-j?'1 i * ry^ ' * vm ca CO SH Vs *" ' *# -Vvi>L*2k , 23 5? S oT ro cj -2: CD O p= ro Lu -- UJ if s o i.d O O*-- oJ-- S2T 2 - v'V^V vV&jg j ,; i'-./V; >.' : ;v >v r, %' ' L; V: v S,Tl'+*SS3**J. , ?,.- v''*`V 'V ' . . .T*?. fv: ``A_V.. > ' ''hli:t*/ - * .> *fiy,r.+. j**-%p** *,f*\ * / 2_BB_00842 , V,-*-.'f* ^ *.. ... .. ".rVv-P'MK.jy*r " > , t' . \; i*1 "-, . `V`. ** 'CJ CO '* ^ f . ;. . i v-** . . ". '*. * ' rK vwns. ;' r>T' ' ';feVj . ` * ' '-tWfy, ^ u. T--* -*-ij SP 5 . ** j*}**.'#-* , ' ,vr l* 9 '*/ rk".*h. .v.. .> ,.. <; i>*'7fA ; > ' 'Tv .;: ; Vk'H Letter from W.R. Blair, o or : 0 U- -*. t-wiwm APPENDIX A - Sr I `M\ .. o : .- ':*m ij O r Co s - y-w$mm ^ <2? * - wfc.' * ,,* * * ' l. *' *fN ** . . V..-J '*. -*z *J,! / Regional Director, u. s. Departm nt I .*jf vyjfv of Labor, Dallas, Texas, to J. H. Bierer, President, Pitts- burgh-Corning. , fi;sp Letter from B. M. Stout, Vice-President, Pi-tsburgh-Corning ::U\jgg$t to W. R. Blair. ' Letters from M. Corn to W. R. Blair. '/. :'h - V !'<?& ' . \ ' - ./.wr >:- M 'aV&r. .: \ 4'`.w * * * if * v ' 'r;. V`*f / / ___________________ '. | BB 0008421 | `V