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UTKLENCM TttL COtMUNV om*+ w lAtfmff/*/ MmIi/i ti\grf*mm^ October 2, 1962 D. 0. StrolwUrs ret Pviat Ccoditieen and Control, Pine Covering Shop. Quine? BereeJth on olx (6) oopleo of Dr. talwtw'* report Of Sopteobar 26, 1962, eac* cvbjoot. Xour Attention is invited to tie eooclueloQa and nmnaalitlma CD J*kCD 4 And S. It to impertaat that recoomendetiorvi 3 *J*i 4 t* eeivded out mH that A r.tudy then be red* oC tha dust flnwUt'ifw In tin shop before any further tonay la invented in oxleriBt y>t*a= havin': Hurrer cepaci^y or mm ri(Un collectors. In the t-sar.tina, It la Inperetivo that rccoaneiziatiOQe 2 mad 6 be fn) Inoail. /A. 0. t**utft 106 M on: ft. X. Braaeoaa F, ft. SarmdD U. F. Ommcl, MJ>. ''T mtrS< * ' ' V-e **t> PLAINTIFFS EXHIBIT fVrfflM.GO **0* wwii < omm 11 *0i r N( Z BETHLEHEM STEEL Qc ifucfacc, fa. D, k. Anderson, Industrial He frith fh^iheer .'^pbetxbof 26, 1962 #M ant A. D, Brandt, J^anener or Industrial Health Sr^lnccrlxag DU3T CONDmOSS AND COinTOL. PIPE COVERING SHOE, QUINCY YARD 1. Introduction Dust concentration* due to various shop activities were Measured at subject location by D. H, Luvaleitc, J. W. Miller and D M* Andersen on 8/JO and 6/J1/62. Both breathing zone and general air ample* total) were taken and subsequently evaluated following the 0, S. Publle Health Service procedures. In addition, tl* performance of the two existing Industrial ventilation systems at subject shop was evaluated fn the stand point of hood airflow and dust collector effluent concentrations* II. Dust Concentration* A. Sampling Result* Tables 1 arri 2 ausmnricc the results of this llsd-ted stapling program. Average breaching-zone dust concentrations (Table -2) varied fTdw 2.2 jcppcf* durii^; prefabi-icotion and sewing to 18.7 appef during band saw cutting. General shop concentrations averaged 2*0 crppcf. It should be pointed ovi that tiwsc averages are subject to revision based upon further sampling which is planned for the near future. The fiber content (fiber* greater than i.0 microns iyi length} varied with the material handled* but in all cases everted lets than 2.2% count. B. Interpretation of Result* Threshold Unita have been establiated for mineral dust* for use a*; guides i_u rhe control of health hazvda and represent condition* _ under which il is UrlieveJ that worixra may be repeatedly exposed, day after day, without mJvvrKe effect. The latest value for asbestos-containing dust which hai been established by the American Conference of Govetrwwntal Industrial ^'gicnists (ACCJH) is t> crppcf (total dust count). Thi* figure is based upon a study in the astjestos textile industry when* worker exposure* were fairly cOiwLant. It has doubtful reliability when applied to pipe covering operations (see reference listed in Table l) where duet exposure is highly variable and weighted-average concentrations vary difficuit to determine. Another factor which cocplicutcs the interpret at ion of dust con centration data i tlwr fiber content of tiw; suspended dust. Although it la known that, contrary to most mineral dusts, it ifi the larT.e (i-e. iong) fibers which Ufni to product aabestoaia, this fact is irnOeed in the present ^ ' wppcf nj Mlons of porT.ic.lc8 per cubic foot of air : * V-v'- A. 0 Brandt -2- Septcabwr 26, 1962 threshold lifrit which is based cn total dust count. The fiber content of the airborne dust sampled in the textile industry study wa$ as high 06 for sCoc 0pcr6li0t5 os conpared to 1 or <5> in the present Study. There fore dudt froo the Quincy shop operations studied is less hazardous than that upon which the threshold limit ns based. Jh view Of the above considerations the threshold Unit of 5 sppcf should be considered only as * guide for control purposes, i.e., a benchmark to shoot for vhen evaluating control procedures. C, Discussion of heqults Comparison of the threshold limit with the listed average dust concentrations of Table 2 shows that several operations produce objection ably high dust concentrations, vis., frinding,-routing, bond saw cutting, packing-handling and sweeping. comparison of average dual con centrations for these operations with tlwse measured elsewhere (see Table 2) indicates lower concentrations ot the Quincy shop titan what might be expected. This Is undoubtedly due to the dust control provided by the existing industrial ventilation systems as well as to a lower work rate than was the case in the other surveys. Despite these encouraging findings, dust control at subject shop cannot be considered good. It can be improved by more efficient operation of the local exhaust system and by the compulsory UC-Of respiratory pro tective equipment (sec "flrcconorvlations11). Tabic 2. also shows that one area of work, which Is a potentially serious dust-producing operation, has yet to be studied, i.e., installation of pipe covering arid other insulation on board ship. Tills is to be studied in the near future (ace "RaccaznondaticM"). Ill. Prrfomancc of Industrial Exhoust Systems A. Hood Performance Table } presents the field data obtained relative to the per formance of tlit two exhaust aystetus at Uwf Quijivy shop. System #1 consists' of hoods at the grinder-router table end the spindle sondej- ducted to a site 10 Acratec "Integral" Dust Collector. The effluent fjrtxn this cOlleeUar is discharged above the building; rOof line vertically dowrwfcrd by seans of o U-bend. System i/2 consists of 5 hoods (2 at the 3}1 band saw 3 at the table-band &e) ducted to a size 60 Acrotec collector. The effluent fTOfe this collector i* discharged beside the six*. 10 Aervtec stack. Hood volume*, o_s alaown in Table 3, nrt detemined by tie loud threat suction method. Total airflow for system waj> 160 cfm, &jk) 1,260 ofio for system /2, These asyeiaiuS arc raved at 300 vfiu and 1,600 cfia, repectiv:.ly. Not only axw these systems operating at lower than possible capacity but the relative diotribution of air flow per pood ia poor. Table 4 Hats the suggested redesign criteria for these two Byatcins which should give optimum dust control with ttie existing equipment. The volume* shown, tuns the 7is;in.ijCTuii rccocx^aied by tiws*,ACXH Af$X have been A, P, Brandt - 3- September 2h, 19&2 shwi, by experience* to provide adequate dust control. Tjwt basic change* in U* t*o evstems nrc the elimination of hood 4C, the connection of hood 1 to system 02 (instead of system 41) and the resizing of connecting ductwork. Hood 4Cf which is a "fii.be Goldberg" attachment VO the table-band *aw, rill not be necessary if flow through hood 48 is maintained os shown. Mood 1 requires either (a.) the full capacity Of system 01 or (b.) connection to A different system, Method (b.) was chosen since the grinder*-router porOdvees the greatest amount of dust (see below) of all ventilated equipnent therefore requiring a large dust storage hopper in the collector, as exists in system 42. (System 02 at rated flow is more then adequate to handle this added hood when air flow is distributed properly, as shown.) The ductwork resizing, together with a better design of the entry to the slac 60 AerOtec (i.e,, Better layout of branch duct entries) will ensure proper la>0d sir flow distribution. After the system is redesigned, as above, the correct air flows will be assured if the hood entry losses are as given in Table 4. B. Collector Performance Table sbowa the observed and rated pressure loss character istics of each system. System #1 is operating at only G05C of rated capacity. -This is due to e collector pressure lose*of six times non&al (32.1 vs. 2.9 ins. water). Similarly, system 02 is operating at only 7V% of rated capacity due to s collector pressure loss of about twice normal (>,V vs. 2.6 ins. water). The cAuie of this Inefficient operation is plugged collector tubes (by visual inspection). These small diameter tubes ore the prxmary dust collection elements of the equlposnt and easily become plugged when the dust hoppers ore not cleaftfd out frequently enough. The units can be returned to and maintained ot proper operating condition* by thorough lube cleaning followed by on enforced program of proper clean out frequency. The bins should never be allowed to become more than about 1/2 to 3/4 full. Table pD presents tie results of limited stack (point-of-diachargw) sampling under conditions of eux-ulialXy maximum dust loading to thv col lectors. It wns invisible to obtain collector inlet loadings either at the hoods or at the collector because of limitation-:? in hood openings and equip ment arrangement. No attempt was mode to sacrple at isokinetie condition* OJtf, therefore, the loadings shown should be considered ait order-of-magnitude Only. Despite this limitation, the effluent concentrations are obviously extremely high for system 01 and higher than desirable for .*grstea 42. It w* observed Umi I}*? affluent from ttese tiro stacks settled rapidly within the boundaries of the Quincy yard. otne mechanical equipment in pearby shape, as well no ported Automobiles in the vicinity have reportedly been affected adversely dv^ to U'je discharge frera these stocks. In addition, the effluent from these c<jj4*t--tor-t, at times, reenUsra the pipe covering shop adding to :.)v existing dust concentrations. Tbc cause of the poor performance of the two collector*, es pecially the eize 10 Aerotec, is the ca% as that which c&uiee the poor A. D. Brandt -i- September St, 1962 hood performance, i.e., collector tube plugging. When the collectors are thoroughly cleaned and properly maintained and when the exhaust systems are redesigned, os oj'.lined above, the effluent concentrations aheuid drop to les* objectionbie levels. In audition to the improvement ahlch should be effected by hcod and collector modifications, the stacks from each system should be modified to a vertical upward orientation and covered with a weather cap. The existing height (5`-6* above roof level) la adequate since extension cr the height might lead to an out'plant problem by increasing the stact fallout trajectory. It may be necessary to change to a sore efficient dual collection system but the above procedure should be followed first. Basic ally inertial collectors, ea ncm installed, should be sdcauate for this problem. TV. Conclusions 1. Objectionably high breathing tone dust concentrations are produced in the shop during grinding-routing, bond saw cutting, pactinghandlisg and sweeping. 2. Further studies of both in-ufapp and on-ship dust conditions are warranted. 3. The in-sftop conditions are due, in port, to poor performance of the two existing industrial exhaust systems which is caused fay poor design end operation of the systems. i. A serious dust fall problexi also exists near the shop due to the poor performance of these systems. 5. Redesign and better operation of the systeaw will reduce both in-shop and outdoor duet problems. V. Recommendations ]. Further studies of dust exposures in the pipe covering shop' and during insulation installation on shipboard should be made aa soon ae practicable in order to more fully evaluate the potential health hasard* of all operations connected with asbestos pipe covcriix! fabrication ami installation at Quincy, 2. Bureau of Mines approved dust reapirntorw should be used fay ail oen atw are engaged in grinding, routine, cutting, pacldne, handling and sweeping and proper supervisory surveillance should be main tained to tec that these respirators are worn properly and consistently during the above operations. - A* P, Brmdt .5 - z*ptmi*r }. Tte two xhaust sysla** oftcuLl be redesigned and reconditioned m follow*: t, Hooda should be relocated and ductwork recited aa ahewrn in Table 4. (Special attention should be given 10 design of the ductwork entry to the else 60 Aerolee unit,) b. T)* duet collector tubes end ductwork should be thoroughly cleaned 4M the fans and factors checked end reccmdltlefaed if necessary. c. The existing stack sections should be replaced with $*-4' vertical sections and provided with weather capa d. The systems should then be bmltncei to five the proper air flows using t-h* hood entry losses listed in Table 4. 4. A rigidly enforced program of daily cleanout of both duet col lectors should be instituted. 5. The use of e portable Industrial vacuus cleaner should be sub stituted for nonup-1 sweepii^. 6. Dust conditions Bixmld be re-evaluated after iwcowndatiou 3, 4 and 2 are in effect. The Office of Iniustrlnl Health Engineering has made arranges*!)t* to assist in following-out recommendation* 1 and 6* DUA:wn D. U. Anderoon - 6Table l. - Airborne Oust Concentrations, I'lrt Covering Shop, Quincy Yard Staple Hwber Pete Dual Coneentratlon conditions Purlnr Senyiimppcf* Percent fiber* (> 10M) A. Routing and Grindire Operations YQu.3146 a/30/62 Breathing zone of worker at ventilated frinder.router tabic continuously routing Kaylo (calcium silicate) sectional Insu lation. Worker wore respirator. Duct work leaking dust into area. YQu-3155 a/30/62 TQu-3169 8/31/62 breathing zone at worker helping grinder.router operator (unpacking, packing, etc.) during routing of Kuyio Insulation (as above). Worker worv respirator. Simultaneoua with YQu-3i46. Same as YQu-3146 on nest day. Worker wore respirator. Ductwork repaired. 6.3 9.6 3.5 B. Band Sow Cutting Operations TQu-3150 8/30/62 TQu-3152 8/30/62 Breathing zone of worker cutting Kayla insulation on ?}' vertical band saw ventilated at tap and bottom of run. worker wore respirator. Similar to XQu-3150. Worker did pot wear respirator. 34 14.4 YQu-3157 8/30/62 TQu-316< 8/30/62 YQu-3170 8/31/62 Breathing zone of worker cutting lVi ralite (ucir.plcs silicates) slabs uo table-band saw ventilated at top actf bottom of run. Worker wore respirator Bottom hood ineffective. Breathing tone of worker assisting operator of tabic-bend cow during operations similar to rQu-3157. Worker did not wear respirator. Approximate breathing taw of worker during operations similar to YQu-3150 on next day. Worker did pot wear respirator. 3? 5.3 2.6 1.1 0.9 0.1 0.5 0.6 1.6 - leave`Vfcweuo ue- 3.3 0.1 flppcT-millions of particles per cubic foot of sir - 7Table 1. - Airborne Dual Concentrations, ripe Covering Shop, Quincy Tart (Cant'd) Staple Number Date Condi tjOiu Durlxur Soaipllix? Du* l Con centration c.ppcf* Percent Tiber* (. l<fc) C. 1Prefabrieation and Sewing Operation* TQu-JUS 8/30/62 General air In south cod of ahop re presentative of exposure of one sever 2 forn-hJn working with aaoaita insulation and asbestos cloth cover* ing. No respirators wore. Avwraga general shop activity. TQu-3156 8/30/62 breathing zone of worker prefabri cating and cementing valve covers using trowel and ealclus silicateasbestos ceocnt. Respirator not wore. TOu-3165 8/30/62 Similar to YCM-31S6. Respirator pot worn. IQu-3171 8/31/62 Repeat of YQu-3l4fl on next day. General ahop activity about average. 1.6 >< 0.96 0.94 0.0 0.0 0.0 D. l&scell anemia Operation* YQu-3151 8/30/62 breathing tone of worker unpacking X^yln actional insulation. No other dust producing activity in shop. Worker wore respirator. 10.0 TQu-3158 8/30/62 Breathing zone of worker boxing Tricallt^ 16.6 slabs. Table-band saw nearby operated 10C of sample tine. Worker wore respirator. TQu-3153 8/30/62 TQu-3154 8/30/62 YQu-3168 8/30/62 Breathing zone of worker sweeping floor on east side of ahop. Floor wetted down lightly beforehand. (Three other sweepers)* 37 General air Of entire chop during and after sweeping. Sweeping one-third of sample time. 13.3 Similar to TQu-3153 (different trweepwr), worker wore respirator. 6-4 1.0 1.8 l.o'" 'yt-v., 0.7 1.2 TQu-3U9 8/30/62 Breathing rone or eoriter cleaning out topper of Aerotec (sire 10) dust col lector and then eeeeping up, Ho reeplrator won, 59 0,3 -8- Table 1. - Airborne Puat Concentrations, Pipe Covering Shop, Quincy Y-rO (Cot`<J) Staple Nipsbe r Pale Conditions During Sampling Duel Con- cent-relian pppcf* - P*f<c**t Fiber* D. XlacellMieou* Operation* (Cont'd) TQu-3167 8/30/62 breathing zone of ork>r cutting flbrrflats oheetlt with portable table Gtv. Cood general ventilation. 2.6 3.8 E. General Step Air TQU-3K7 6/30/62 General air of entire shop during average activity. Fair general ventilation. TQu-3159 8/30/62 General air of entire shop during lunch period- Fair general ventilation. TQu-3166 8/30/62 General of entire jhop during period of little dust production {assembly operations only). Fair general vent!-- latlctt. JQu-3172 6/31/62 General air of shop area in vicinity of routing and sawing or*a*. Average activity, (iknac dust from A^rotec effluent reenter* shop,} 2.5 2.3 O.U 3.1 0.J 0.0 0,0.,. _... w 0.0 Table 2. - Aieregc Pvut Concentrations and Comparison with Other Studle* A. Average feveentratloo* Operation Grind leg -Routing Band Saar Cutting Prefabrlcatlaa Saying Paeking.H&Ddllog Steeply Cbneral Shop Aboard Ship Ho. Stcolci 3 2 A 2 3 4 ' Duct Conccntratiotwnppef UpatuT^d Duct Concentration pof Reported iieevtera* Ru^je 3-5 2.6 0.9 10,0 * 9.8 - 37 - 5-4 - 16.6 6.4 - 37 0.1 - 3.1 ... Average fUAee 6.5 ia.7 2r2 13.1 IS.6 2.0 - 9.4 - ICO* 11.0 - IOO 2.1 - 12.3 -- 0.0 - 24.6 fl.O - 250 Averaga *0* 42* 6.2 --- --- 8.2 82 B, Average Fiber Contest thiat Source Ho. Scarplee Kayle insulation (calcluia vlll<rate) Trlcallte liuul*tio(cen>ple* ellleetec) General 12 2 11 Percent Fiber* ^H^i) R*j* Awrite ,. 0.3 - 2.0 1.6 - 3.3 0.0 - 1.4 1.0 2.2 0.4 Set Fleischer, f,E.# Vileif F.J,, Cede, R.L. and Printer, P,t nA Health Survey Cf Ripe Covering Operations in Constructing Nevul Veoeelft", J. Ind, tt?. and Tori.col., 28. 9 (1946). /XK*v.. Performance o f In d u s tria l V e n tila tio n S ystaiss, P ipe C overing Shop, Q uincy T a rt il -3 - *2* ae i(fV; 0 <? y5 t is i- la*$` V QH Ul W * O 3 * la V 2 8 88 O W rv S 73 H (j> MS MS bs o o I* c 3 3 3 E< U/ *E y ii .iJ e ft-1 i o o e 5 if* K 2 gsass S --* f*- -< -M *M (V ooooo V"\ a r-v r*\ r-v O OOOO 10 f '/O'tb Q<y e 3e I 3* *5? (X+* S J8 S 5 S v r r .O J ; ,-> a. i. * su a t> * 3SS a~il O *> \i rv fM tft is 22 > -* HO <y * 8 Sic J U 58 2*- 88 x CM O. > <M Vl H * *> 3 n u n etc CM #-l o* & &g T? O S 28 33 SS E 22 o S -<1 i* A *2 ^o 0- E w3 l< a. s- { . t5 SS m rM f* mH 4 -*<* ->< .1 ta b le j . - P erfop-aixe o f In d u s tria l V e n tila tio n Systems, Pipe C overlrp Shop, (Jutncy la rd (to u t'd ) -u Table 4. - Kensisended Exhaust Volumes for Existing Ventilation Syateua, A. System A (Aerotec-slze 10) (300 cfm capacity) Mood* 2 Total . location Spindle sender Minima flow required cfm 300 Kepi ace with duet diaa. Ins. 4.5 Correct Entry Loaa (h,) ins. water 1.2 B. - System fi (Acrotec-alzc 60) (1,600 cfm capacity) 1 grinder-router table 31 3^' band saw - XOp 3B " " - bottcei 4A table-band sew - top 4B - - . bottom 4C ranovc Total........................................................................... 350 350 " 350 350 350 1,750 * eiuic designation as Table 3 4.5 4.5 4.5 4.5 4.5 1.1 1.2 1.2 1.2 1.2