Document 06QadmdjZV8joRqDD2jZXX3gm

* * I^BtRIAL HYGIENE POLLUTION Morton Corn, ph. d., b. ch. CONSULTING ENGINEER >10 BOWER HI EL ROAD PITTSBURGH. PENNSYLVANIA 15226 e. 1 TELEPHONE 412 . >ei.237 October 16, 1968 Dr. Lee Grant j Pittsburgh Plate Glass Corporation One Gateway Center / ! / Pittsburgh, Pennsylvania' V ADear Lee: / / ,. ............................ The Port Allegany Pi an^survey report is enclosed. As you will see, 4ny opinion based on .the data obtained is that a redesign of the exhaust ...system is in order. I am fully aware of the future efforts associated with this recommendation but cannot reach any other conclusion'In view of the measures taken .to ensure that the system was operating';^at high efficiency .during'*my, survey. Thus, at best performa'ng'e,d;'t..is just not good enough. ^ V/ / In accordance witjy'^orur request, the report dofes not dwell on design aspects because btfr.'jSjirpose was to determin'e wj^eloe we stand at present. %'Ha ' Va Sincerely yours, MC/pfh Enclosure Morton Corn, Ph.D. THIS DOCUMENT WS JjfJoT cOmTfBOM ftLES^AND CANNOT BE AUTHENTICATED by PPG INDUSTRIES, INC. 1> ft | BB 0008708 ^ i Report on THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DiO NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. | BB 0008709 I <0 TABLE OF CONTENTS II. III. IV. V. COMMENDATIONS THRESH arilT/iVALUES OF SUBSTANCES MEASURED IN THIS SURVEY / S^lPLlNte DESCRIPTION OF AND ANALYTICAL METHODS RESULTS AND DIS* C/US\SION.//\ 1 1 2 3 4 % ?S>. V 'VO THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM ITS FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. I. INTRODUCTION i\ \ \\ A survey of airborne dust concentrations- was performed in the Unibestos area of the Pittsburgh-Corning Port Allegany plant on August. 27-28 by Dr. Morton Corn. The survey was performed at the request of Lee Grant, M.D., Medical Director, PPG Industries. The survey was aimed specifically at assessing the degree of dust control achieved in the Unibestos facility with the improvements made since the former survey by the author in April, 1966. Also, because a new assessment technique for asbestos fibers (Membrane filter) used, the present survey was performed by simultan4*ouk%y sampling at the same location with the traditional sampling -infftrjunentx midget impinger) and the new instrument. * During thfc peruiopdajotf the survey outdoor weather conditions were clear, cool, ana^guWn^y,,//wwiith outdoor temperatures in the range 60-75F. j//\ It should be noted that the dust collection system in the // Unibestos facility was thoroughly.-cleaned during the week prior to this survey here fore, it/can be reasonably assumed that dust concentrations measured in this..survey/are representative of the lowest concentratibns/phich can be achieved, with the present dust control system. V:- vw-o'.. II. SUMMARY AND RECOMMENDATIONS // V This survey was per formed;-.by simultaneous sypling airborne dust in the Unibestos plant'by'different ^echpaques. Results of both methods of assessment sug^i^t that dust^opCTSntfrations in the plant are high when judged by the present U. S. Threshbld/timit Value for asbestos dust, or by the recently proposed Britisnguidelines for asbestos dust. Because the dust collection system was operating at, or close to the maximum efficiency achievable with present facilities, modifications and additions to the present system would appear to be . in order. It is beyond the scope of this report to present detail d recommendations for system modification, but certain obvious major sources of dust emission in the plant as cited in Section V of this report. 7 bb~00087iT"T It is recommended that attention be focussed on major redesign J2 th present system. It is obvious that additional air capacity for new local exhaust hoods will be necessary, and that this capacity probably cannot be found in the present system, which was not adequat ly handling existing hoods. . ,!!^,,N0T A REC0RD 0F ' PPG INDUSTRIES, INC. DID NOT COME FROM . IT'S FILES AND CANNOT BE AUTHENTICATED UY PPG INDUSTRIES, INC. J.J.. ^-uul ur A>r>.;> i.U> DUST i TThe threshold lim_ u values refer to airborne concentrations of substances and represent conditions under which it is believed that .early all workers may be repeatedly exposed, day after day, without ^fe3verse effect. Because of wide variation in individual susceptibility ^exposures of an occasional individual at or even 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 safe and dangeroup'-EEfnditions." * The American Conference of Governmental Industrial Hygienists had/ in x9 67, ifT'Tl^V. for asbestos of 5 million particles per cubic foot, as" determinedjby impinger sampling and counting by light-field techniques, iSju-dopsidered revision (1968), the Conference endorsed the retention of this T.L'.V-*, for "most forms of asbestos". However, :. | / / x for crocidolite, because o^. the production of mesotheliomas, it was recommended that workers^e equipped with air-supplied helmets because / "no safe limit can be established for this form of asbestos at this time." The Brit^kh Occupational Hygiene society recently issued hygienic 1: . - : ^ '' / . ta"rida'rds 'for Cfctysotile asbestos duSt'.k^* /`The standards are based on w ^ * ... t ^Phe" objective thati'the risk of contracting asbestos be reduced to 1 per cent" of *thdSe. ;wh'o" have" a lifetime's expos urevto the dust. By * - ; ,* _ <-* 'I/ ,*.*_* ! > /' 5,1- 'a* sf* KbaeAs^toA'PsIi's" "thAe cbjhn^utteAeA mAeaawn^t theA Aeawrllies^t demonstrable*9 AanAflh aJL Balk A effaeAci.tms m on the"'lung due to* asbestos.' * These standards are ci^ed hrf3e because they are" "more" stringent than' 'the* U.S. guideline ref errecttslab'ova. The exposure guideline's' *areY ' Stable i fe:RlTIs1f WGl'ENIC GUIDELINES FOR ASBESTOS DUST 1. . A *- * . . . DUST CATEGORY ,, CONCENTRATION AVERAGED OVER 3 MONTHS 3 Fibers/cm MPPCF*** Negligible '' Low : Medium High 0 - 0.4 0.5 - 1.9 . 2.0 - 10 over 10 ... 0.011 0.014 - 0.054 0.057 - 0.28 over 0.28 Extracted from the Preface, Threshold Limit Values for 1968. American Conference of Governmental Industrial Hygienists, 1014 Broadway, Cincinnati, Ohio 45202. ** Ann. Occup. Hyg. 11, 47-69 (1968). ** Million particles per cubic foot (as fibers). , n,,0 0r this DOCUMENT COm FROM1 -2- rrirESANDC^NOTBE By PPG INDUSTRIES, IN - r-- 1 BB 0008712 4 '} i ' .. Th concentration- refer to fibers greater i_nan b macrons in length as determined by the membrane filter method. IV.- DESCRIPTION OF SAMPLING AND ANALYTICAL METHODS Because of the current state of evaluation of th methods of assessing the potential hazard of asbestos dust, the standard impinger technique and the membrane filter technique were used in this survey. A. Impinger Method A midget impinger containing 10 ml of demineralized, distilled water was operated at 0.1 cfm air flow rate by means of a battery operatedfoump. ^ Samples were agitated prior to withdrawing drops of suspensionfor excnination in a Spencer Brightline Haemocytometer Cell. Particles ws^e /counted by viewing the sample with an objective lens of 0.25 Numerical\gerOr^|(lOx) and a 15x Ocular. Approximately 200-300 particles were couqtpfi an e^ch size class, except where frequency of occurrence in the vifev^.40^fy^l^-was very low, indicating concentrations in air far below the thre^^ld limit value. The counting standard deviation was estimated , w^ere N is the total count for the sample. A blank count was mades^n^the ^1's^illed water. Dust concen tration in the air, expressed as milljitin^ of^particles per cubic foot .MPPCF) , was calculated from the sampl^ vo.Iui&e, liquid collection eservoir, and pimple and blank dust co B. Membrane''!^Iter Method if A membrane filter (Type HA Millipore) Oas jfsedfip obtain samples for microscopic evaluation of fiber and dust part^cle^oncentrations. This paper is composed of^pores 0.45 microns in size ana has been shown to retain, with 100% efficiency, particles down to 0.05 m^ron diamet r1. Th^ .filter was first Visually examined to detect any loose dust or uneven dust deposition. In the-few cases where the filter deposit did . ' ''t not pass this examination it was necessary to resuspend the collect d dust in distilled water and refilter this suspension on VF.grade Millipore filter to assure an even dust distribution over the entir filter area. A pie shaped segment of the filter was then placed on a microscope slide and rendered completely transparent with Cargille certifi d index of refraction liquids. Cargille liquid of index of _____________________________________ I BB 000871J-7 t :1 Megaw, W.J. and Wiffen, R.D.: Int. J. Air Wat. Poll. 1, 501 (1963). -3- TH1S DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. nefraction 1.500 was us ^lly most suitable. The funting of the dust particles and the counting and sizing of asbestos fibers was performed with the aid of a Zeiss Photomicroscope using Phase Contrast Illumination. The objective lens was a Zeiss Neofluor Ph 63x with a numerical aperture f 0.90. The eyepiece had a magnification of 20x and contained a calibrated Porton graticule. The optovar feature of the 2eiss scope contributed to the total magnification of 2016x. Resolution was approximately 0.35 microns. Particles and fibers of size 0.30 microns could be dejected. In tlfe evaluation procedure, all particles and fibers in the Porton fiel-d of vjjaw were counted and the fibers were grouped by fiber length intoEhrffe categories (less than five microns, five to ten microns, and larger than ten microfis). This procedure was repeated for a number of randomly selected fie^esfonythe face of the filter. Because only a portion of the total filcet ar^a^ was evaluated by this method, it was "necessary to correct the cp<irrt. by/the ratio of the total filter arm. to 'the evaluated area. The re sul^ny'p article or fiber number was divided "by "the volume of `the air sample o obtain dust or fiber concentration - ^ rf N. "` xpressed as millions of parti deeper/cubic ^foot (MPPCF) . The statistical reliability of the evaluation was expressed as ............. . /5_/ f / ce "standard deviation, calculated as N where 43 is the particle or iber "count. : - :: - /^ "The procedure "soutlined follows, in its e__s__s_^>1ft.tia./r points, that . .. .recommended by J. R.vLynch and H. E.Ayer in their/a/a:r - _ ... ***/*"} "Measurement ~ f Asbestos Exposure^o^which appeared in the Journal of tional -Medicine," Volume 10, January,, 1968. ; * : * ' -- V.-^'"RESULTS "AND DISCUVSI<5>/;., : - : - - - -- Measured concentrations?;!^'dust *and asbestos fibers are summarized t* * . . , * B p #t iy' _ * 1 t "in Tabl 2;- All-samples were'/obtaxhed in the breathing zone of men or - -- - ... . . .Cy:' `at breathing level in areas where men,were not at work at the time 'samples were obtained (in aisles, for instance}. Impinger and membrane filter samples were obtained simultaneously at the sites shown. Only *at the last five sites were midget impingers used without simultaneous m mbrane filters operating. ... It is seldom that air sampling reveals a picture as consist nt -as the one depicted by the data in Table 2. With the exception of two samples obtained with the impinger, all results indicate concentrations _LBB_ 0087J "7 -4- THIS DOCUMENT WAS NOT A RECORD OF PPG.INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. in excess of the preser U.S. Threshold^Limit vld of 5 MPPCF. it \i should be noted that the U.S.T.L.V. is in terms of total particles c and not fibers alone. This approach stems from epidemiological methods .nitially used in surveying the asbestos industries. According to the ^^ritish classification, three membrane filter samples were in the Medium dust category (0.057-0.28 million fibers (>5 um) per cubic foot) and the remaining six samples were in the High dust category ( 0.28 million fibers (>5 um) per cubic foot). These results suggest that with the present dust control facilities operating under jwptimum conditions of maintenance, dust concentrations are high in the Unxbestos\ plant. .The highe^concertrations of dust were measured at cutting stations and in the vicinity 6f the j feed Stations in the raw materials formulation area. The high results a>r tfr^ buildup station were due to dust from the f ed area backing up to thSbjiilsS^ip area. The high dust levels at the Uniclad area are surprising, btat it* was noted that the men use a special abrasive sponge to smooth the rolls and this may contribute to the dust. Exhaust hoods are not used in this areaC % l... . .-Possible major sources of the excessive <3ust ar not hard to pinpoint nd they .will now be cited. . . .. .Af ' Raw materials formulation area. v pJS<t --1. - T^S^sfer of asbestos from bags 'to^feed^hi^s and recovered asbestos from th^9pllection "house" to bins are ^najor^sburces of dust emission. Present d'^forts directed at pneumatic pickup Af scrap will reduce the latter 's&ur'cb. . ... -- .. ... r..: 1 :^ :ir.;2.":Line fe^d/fcih .hoods are not effective baseaonbmeaswred SP/c.'.',, T/ face velocities. The-newvhin^hood design is superior to thqr olu design, but the.-need to :open.asbestos\bags from.the-tops iofibins-results in-low air velocities at-the bases kjf'-lii'n-opening faces. '=The-problem is the t,-) sloping face design of the bin entl^E* - ` - -- - = - 3. Low room air velocities in-the feed area indicates poor air turnover in this room. Velocities were 20-30 fpm. - =' ~ - -4.* Doors remain open in the scrap storage bin and dust enters the room-as material drops to the base of the bin and "pulses" the dust laden air outward. . - - --------------iLJ?008715 I 5 - - THIS DOCUMENT WAS NOT A RECORD OF _PPG INDUSTRIES, INC. DID NpT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED Date and Time of Sampl Description of Sampling Site Si 2 novations at selected plant locations Dust or Fiber Impinger Sampling tI Particles Fibers Concentration, Fibers < 5 pm MPPCF + Standard Deviation Membrane Filter Sampling Fibers j Fibers 5 - lJLpm 1 >10 pm * Parti. 27 It05 PM- Loader BZ* 'Cutting 6.1 + 0.6 1:15 PM Unibestos (2* x 6") on Line No. 2 27 1:25 PM- Unloader BZ* Cut 6*2 + 0*6 0.60 + 0.17 0.65 +fJ). 10 1.54 + 0.11 0.82 + 0.11 70.097 + 0.0)28 SX ro.077V 0.034 1:35 PM ting Unibestos (2* x 6") on Line No. 2 27 1:45 PM- Unloader BZ* Cut1:55 PM ting Unibestos (2 1/2' x 16") Line No. 3 aV> 19.2 + CN* ^.95 rX r + -- 0.31 X 2.17 + (TuiT "0714 X\ V, ///> + 0.05 27 2:25 PM- Loader BZ* Cut2:35 PM ting Unibestos (2 1/2'- x 16") Line No. 3 27 3:05 fcM- General Back3:15 PM ground in Aisles at breathing 1 vel. Opposite office adjacent AN* `OV'* !-7 2.9 + 0.4 3.20 + 0.56 1.62 1\0.15 V a/v 0.80 + 0*^20/ 0->.93 --+ 0.11 / >s 0.23 + 0.06 0.49 + 0.08 to cutting area 27 4:20 PM- Raw Materials & 4:30 PM Line Formulation Area Line Feed Op rator BZ* in vicinity of Lines 1A, IB, fi le. Note: large amounts of visible dust. Breathing Zone. 10.0 + 0.7. Xoo Vo.32 4.74 + 0.28 0.51 + 0.09 > 1 tu 1 O1 lot I --I iONi s3!aisnaNi odd as I '4 { O3iV0IiN3HJfW 3? ..Ch'jNVO ONV S31fd S,XI i--* woyd tv'Qj ,o.:|! via 'ssiaisnaKn odd jo o' oo:-.b v iQwt &m injnnooa sihi 0.051 + 0.021 2.40 + 0.015 + 0.015 2.34 + 0.017 + 0.017 3.62 + 0.071 + 0.032 2.44 + 0,44 + 0.08 6.69" +~ - ^v"H 0.22 + 0.06 5.72-+- TABLE inued) Date and Time of Sample Description of Sampling Site Dust or Fiber Concentration, MPPCF +_ Standard Devlatl Impinger Sampling 1 Fibers Membrane Filter Sampling Fibers Fibers Particles Fibers <5 un 5 - 10 um >10 um Partic 8/27 4:35 PM- Raw materials and 44.3 + 2.1 6.40 + 0.80 4.43 + 0.29>"f78&\+ 0..19 0.72 + 0.11 7.07 + * 4:45 PM Line Formulation .. ( TArea Background i i . " Sampling at breath ing level Note: Large amounts' of visible dust 4 'V XU 8/28 8:30 AM- Breathing Level Xp.c2;3H 0.3 0.40 + 0.14 1.40 0.15 + 0.05 0.074 + 7.38 8:40 AM Adjacent to Kiln (in aisle opposite , 'Vc./ \\ 0.037 control panel) . /\ ' v** v 8/28*8:55 AM- Raw materials and> / . 5.2 + 0.5 0.50 + 0-.16" 4^7^ + 0.29 0.57 + 0.10 0.31 + 0.07 6.98 + ( 9:05 AM Line Formulatio^v Area. Breathing Level in vicinify' of Lines 1 an&;-2* bins and adja^nt to s torage area. / V 8/28 9:35 AM- BZ* of builder ,4' 32.0 + 1.8 X,20'+ 0.96 9:45 AM operator at Line No. 2 (2' x 6" rolls) 8/28 9:50 AM- BZ* of builder 10:00 AM operator at Line No. 1 0.50 + 0.16 8/28 JO:05 AM- Breathing level 10:15 AM in storage area: behind Lines No. 1 and 2. Feed bins (Asbestos and Decalite bag j storage) .___________ Breathing Zone. 2.10 + 0.32 i Qi *on! 'sdiaisnoMT Was j -- * l31V0liM3HinV 30 C: . ;d$JJ I 00 j MOdd 3VM00 '0*' r Ci . 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