Document dn8adqoJX24q4kaapG8nMNL5G

1 1 -~13' SPECIAL REPORT vmn.Tl EKSTOS- OOEPOHAIIO* X3V USTLZ, UDIAIA. jjrprrc'TTTrL BJOIKSI STUD! KiX 19, 1&47 t . LOSS PREVENTION DEPARTMENT z nMinmwtin i EXHIBIT I t KCZLD 3STDS COEPCSUTTar rsr castls. Trirrira ~ X fiaat stodj' m asd* at sereral operations _ in tlx brsJcr 1 iein^- xaa- nfaetcre to dateraise the epomt to lead and to ubei toe 4a*t. This report glees the revolt* of oar teat* with a discasslnm erf the hexarda stadded and reconaradttions to add in the control of the . exposure*. ! ' j i ffiwdgT irn renrrrasiDg Ki g* rnrnwrtratlcns of lead dnst is adr were foond at the batching operation* daring the weighing cf litharge and at the sheet prefczat pres*. Control of the lead and dost exposures at these operations <oi needed. Concentration* of lead ahowe the a^-riene allowable concentration*' were fonnd daring the operation of the alii in the J. X. canar of the wnjnrMMu room, This u sot a coctinsorna operation aid it 1* not thought that a serious lead exposare existed at this operation, nowewer, it weald he adri'aahle to consider better control of the dost at this mill. Dost coants at the asbestos shredding mill were nodemteijr high end ixoreTBsext da the eaclcsare of the nachine is rrcc--mi'ed. I ) 9h\.t r 3 w ' A. 4 i sTOHAjg py.,.gcPKHnmmgaa Compounding rooat 1.. Install exhausted partial enclosure! at the hatching scale and at the supply 'barrels of litharge, plastic povders and excessively dnmty powders. See attached sketch. 2. Install cleanout doors in the duet work of the exhaust its tee In the compounding room to make a periodic cleanout at the elbows and bends. Hill la the compounding room: 3. It would be advisable to bring the exhaust hood closer to the rolls of the mill on one side at least, and to increase the amount of air ex hausted. The Increase in the amount of air might possibly be obtained by cleanout of the present exhaust system. Asbestos shredding nachii^i 4. Close up or block off the openings along the seams of the machine en closure to confine the dust and extend the enclosure to cover the chute at the^ discharge end. The present exhaust System should be satisfactory but the duct work must be cleaned out periodically. Sheet preform ureas: . ' 5. Construct a curtain or shield, around the ram to fit like a box cover in order to trap the surge of dust. The Shield should extend from the outside of the exhaust slots to a short distance below the bottom of the ram. If necessary construct an offset in the shield to go over the outside of the bed plate. Bsnsrali 6. Install clean-out openings near all bends and elbows of exhaust ducts and have the dusts cleaned out periodically. . (akm>(Wu M tjsi --v,.-h Standard^ Lead A maximum allowable concentration of 1.6 milligrams of lead per-lO cubic Beteri of air for lead and lte cosipoundt ha* been generally accepted by health authorltie*. Thl* figure it meant a* an average for an eight Its nr exposure and concentration! nay exceed thit figure for abort period* if there are correspondingly lower figure* at other time*. It la believed. how ever, that .concentration* of lead in air ehould not exceed 5 milligrams per 10 cubic aeter*. Asbestos X figure of 5 Billion particles of asbestos du*t per cubic foot of air ha* been widely quoted a* a maximum allowable concentration fro this duet. Ve believe that thi* rtgure l* too high and wonld prefer to in the du*t level* for asbestos duat kept below 3 Billion and preferably about 1 million particle* per cubic foot. The duat froe the handling of aibeato* contained about 5 to 6^ of asbestos flbert and a eoniervatlve estimate would be about 10^. The duat also con tained serpentine which 1* chemically identical with asbestos ( chryaotiXe) but its physical characteristic* are different and this nlneral is considered more of a nuisance dust. Discussion ' Batching operations near the 'Ranenme mixers Although the total duat con centrations at the hatching operations was high at times, only three of the materials bandied vers considered to be objectionable from a health stand point. These material* were: Lead (litharge) Asbestoe . Plastic powder The other dusts are ordinarily considered nuisanci dusts. Lead: The exposure to lead dust during the batching and dumping of the litharge was of comparatively short duration but the concentrations were high during this operation. This dust was. spread throughout the department and lead was found in the settled dust sample* and In the general room air during ordinary operations which did not Involve the handling of litharge. Asbestos: The exposures to asbestos dust were of short duration and occurred In the weighing and dumping of the material. Appreciable amounts of asbestos dust were not present at other times. Plastic powders: The composition of the plastic powder in use was not known but these materials are partially polymerired plastics and certain types are known to be irritants. The type* of plasties used have changed from time to " time and with the uncertainty of the particular characteristics of the material* in use it is advisable to handle these powders carefully and to . control the dust dispersed in handling them. Bespirator* were .used regularly at the batching operations and these will provide the necessary protection against toxic dusts and against the other -. ..'at i % 'n' A n "ir- a: r dust*. But respirator* should bw considered as temporary expedient* for- they ere difficult to veer la were weather. The effect of the exhaust at ih* hatching was negligible In controlling there duets and a better type pf *nclosure and exhaust would be desirable. If the present procedures were continued It would be advisable to ihetall a. hood which would extend partially over and around the barrel on the scale. It would be advisable to install similar partial enclosures around the supply boxee or barrels of the litharge, the plastic powder* and other very dusty nuisance dusts such as the carbon. k sketch is attached showing the type of hood suggested. . - i. similar enclosure and exhauat would be necessary for the circular type of batching table proposed and this would be much more difficult to exhaust for the barrels on the rotating table would have to pass by the enclosure and much of its effectiveness would be lost, k similar type of exhaust would still be necessary for the receiving barrel on the meals. Thmmlnr batches Into the hopper of the Ransnne mixers High dust count* were obtained at the toppers with the exhaust turned off, but the dust concentrat ions dropped off considerably with the exhaust tuned on. It was not possible to quantitate this decrease.for part of the dnst came from the batching op eration In the tenter of the room. The enclosure and exhaust at these hoppers should satisfactorily control the dust after the completion of the proposed rearrangement of the duct system# and increase in the amount of air exhausted. Clean-out doors should be installed in the duct work of this system in order to make periodic cleaning* at the bends and elbows. _ Hill operation (HI corner of compounding room) The concentration* of lead In the air during the operation of the mill were higher than tbs maximum allow able concentration but part of. this dust may have spread from the batching operation for there was general room contamination of lead. The operation of the mill was intermittent and an average concentration would be below the maximum allowable concentration. This operation was not considered a serious hazard. ' ." . Tor complete control it would be advisable to ertend the hood at this machine to bring at least one side of it closer to the point where the powdered mater ials are dumped on the rolls. An increase in the amount of air exhausted would be necessary, but this may possibly be done by a check on the present exhaust and dean out of the system. There were indications at this operation of possible blocking in the exhaust ducts. A-ebeetos shre^d^f The hand preparation of the asbestos string before shred ding dispersed a small emount of dust but this was rapidly dispersed and the large sire of the room prevented any appreciable concentrations of dust from building up. Control at this operation was not considered necessary. The shredding machine was enclosed and exhausted but numerous leak* In the enclosure permitted the dust to escape. Dust counts at this machine varied from 8 to SO million and this would mean asbestos dust from 0,6 to 5 million. The exposure was not continuous, the high count did not represent a breathing zone cample and it was not considered a serious exposure. However, it is advisable to keep con can trations of this dust at a minimum and the separations l .5 .;,3t * 'lj V * h w. i V along tha Jolnti and <uu of the enclosure afaonld be dosed or/faloeiad off to confine the dost and permit the exhaust to capture it. The-chbnte at the discharge end should he partially covered and feeds continuous irlth tha rest of the enclosure. Sheet preform ureas The concentration of lead dnat la the hreatlxlng rone of the operator of the preform press was excessive and above 10 tllllgraas per ten cubic Deters. Dost counts vere not taJcen at this operatj_on hut the total aaount of dust present vaa high and an appreciable quantity of this dust vaa asbestos dnat. . The present exhaust system on the press vss partially effective brat the slots around the edge vere narrow, they did not extend around tha sides of tha ram and vere too far avay from the source to capture the surges of dust from the bed. The openings to the hood should he vider, probably at least 3 Inches vide for its effectiveness depends store on the quantity of air exhanst-ed than oa the velocity through the slot. .A aetal curtain or shield should "be built down from the exhaust slots and enclose the raa so that it would coma down as a cover over the bed. This curtain should extend so that the bottom edgrn will be about 2 inches below the bottom of the raa and it may be neeeasjqry to offset the bottom of the shield to permit it to paas the bed plate. The velocity of air exhausted should be at learnt 250 linear feet per minute through the opening between the raa and the curtain. General Asbestos dust will readily accumulate in pipe elbows and bends in exhaust systems and clean--out traps should be Installed at convenient spots near the bends. X regular program for periodic cleanout of these pointa should be made in order to maintain the exhanst systems at their best efficiency. _' .. /J ' ` V .A. Houghton Division of Industrial Hygiaae ' i I. .3 ' : s'. Aj-ft 1! L V F"- \ '. 5 * _--- --*"L Vr4 ; F! ~ ^ M- '*. ' ' *! * ' . 5 7i 1 e'i ) . ` j' ' j '. * 3 j. .. ;: ' . * CL--.. ; .Y - ---- - i:m r* v**s**-:. Sample* v&re taken for lead duet vlth a single nid^et ijcpta^ej: aacrplln^ at ( rate of 5 liter* per nlzsite. The easplet vere collected in dilute nitric ' add &nd &naly*ed colorluetrically vlth dithizonc* location of Samples i Tlae ' Kllli.gra= of lead par 10 gsMc meters of air At batching seals near caster of roos- sample tatea about 5 feet from the operator, no litharge vd^ied out dor- leg the sample. ' . 30 min. General roon air compounding rooa sear Hassone adxax. 20 da. 2.1 * 3-0 At betching scale at dde of rooalitharge.included in batch vdghed out. 6 min. 12.2 Operators breathing ar ea at mill in XX comer of compounding room. 16 zdn. Z.5 ~ It rrin in XX corner of compounding mens about S feet from mill. 16 min. 2.6 r At scale of sheet preforming press- general area near operator vdgfaing oat dx. . . 30 min. . JU7 At preforming press-general breathing area of operator spreading mix and operating the nachj ns. 33 aia. 12.4 i BZSULTS 07 HJ3T COHUTS Grab sampl e were taken with the Snatch and Lomb dost counter and count ad .with darle field illumination. Icpstlcs cf Sensle . Millions of particles TfT cubic foot of nir feeding the asbestos shredding machine -- operator! breathing tone. 7.5 12.7 Over center of asbestos shredding machine risible cloud of duet riling free nachina. 47.1 19.8 it discharge chute of asbestos shredding narhl ne -- about 3 feet from the floor. 14.9 8.6 Dumping asbestos from bag into hopper of Seasons mixer - exhaust not operating. over 50 million oxer 50 Billion General rooa air of compounding room shout 10 feet from hatching operation. 20. 8 20.5 . _ PgnPOiPHIC iSiilTSIS 07 ilB SAXPLSS . Air samples taken with the Bauach and Lcnb sampler were examined petrogrepbically ud a determination of the asbestos was made by particle count. #1 Taken at asbestoa shredding machine. Coaposed of particles of serpentine, dolomite, magnetite, .etc., below 5 ai crons and 6$ asbestos fibers (warlaua length GO ml exons) by count. tZ Taken at dumping material into hopper of Baneoae aizar. Sample is similar to #1 - contains 5^ asbestos fibers by count. (C. E. Villi am a}