Document 72K4vm739ReaR1yed72ddLnE

CITY COUNCIL ROBERT J. FURLONG. Mayor GENEVIEVE H. ANDERSON CHARLES H. MAILLIARD JUDITH M. POXON LEONIS C. MAL6URG TIUPMOMM Crrr clcwk - . Police Dipt. . - Ludlow S-lftftft Q.U0LOw.7-$2B7 * ILUOLOW 7-8133 Pine Derr. .... LUolow ft.2022 Buildino Deft. - - LUolow 3-lOftfi ExomciftiPta Ocft. LUdlow 3-1066 health Derr. - - - LUdlow 3*1606 CITY HALL 4303 Santa PC Avenue VERNON 58. CALIFORNIA January 24, 1962 Aluminum Company of America 5151 Alcoa Avenue Vernon 58, California Attention: Mr. Frank Regehr, Safety Director Of PICIM F. A. ZlEMSft. City Clefk L R. 9URCM. City Tfcasufep # INCENT R POXON. CiTY ATTOANIT ARTHUR E NELSON. Jn.. City E.ninei D. D GRAY SON. Traffic Enoineea R H KING. Supt.. Watii ft Scwia Syitimi OR. C. C. NEMETHI. Health Office* J. S. COLTON. BUILOimo ENOiNKin LESTER C HUSTCO. Fine Chief R. H. BOCKH ACKER. POLICE Chief JOHN B. MOORE. Adminiitrativc Office* HASKINS ft SELLS. AUDIT** IN REPLY REFER TO: Dept, of Public Health SUBJECT: Preliminary study of a proposed "Marinite" cutting operation in the pattern shop. PLAINTIFF'S - EXHIBIT 3 AL-329 Gentlemen: On January 12, 1962, representatives of the Vernon Health Department conducted a preliminary study of a "marinite" cutting operation in the pattern shop. The pieces of "marinite" were cut on a band saw which is pro vided with a local exhaust connection to the lower pulley housing and a small hood located directly under the blade opening in the saw table. Air movement observations were conducted during the cutting operation using smoke tubes and a velometer. Close observation of the blade as it passed through the material disclosed that fine dust was being generated from tfte top surface of the "marinite" similar to conditions that are encountered in crushing operations. This top surface generation explains why considerable dust was encountered even though an adequate exhaust hood was provided below the saw table. In discussing this operation with Mr. Smythe and pattern shop personnel, I learned that "marinite" was cut rather infrequently and probably the time spent did not exceed an average of roor< *-han 12 hours monthly. *nOH 19189 I  January 24, 1962 Dept, of Public Health This time factor of course decreased the hazard potential of the operation, but because of the composition of the material local exhaust.controls should be instituted. It was also seated that large pieces of the material were cut outdoors using a skill saw. A sample of the material has been submitted to the laboratory for analysis and as soon as we receive the report, it will be for warded to you. An inspection of the local exhaust duct system in the pattern shop was also made during this study and you will find suggestions in regard to this system listed in our recommendations. RECOMMENDATIONS: (SHOULD THE "MARINITE" CUTTING BE RESUMED) 1. Provide a transparent cylindrical plastic hood to enclose the blade above the material. This hood should be approximately 6" in diameter and long enough to leave about 1/2" of space above the material being cut. The hood should be attached to the upper saw blade guide (angle iron). It is suggested that the top portion of the hood be made of a circular disk of 1/2" plywood slotted to receive the blade. The plastic cylinder should be of material similar to that used in plastic face shields and screwed or tacked to the plywood disk. The plywood disk must also be provided with a hole to receive the flexible exhaust duct. (See attached drawing VS-48.) Approximately 350 cubic feet per minute exhaust volume should be provided. 2. Connect the under table hood to the same exhaust duct supplying the lower pulley housing. (See attached drawing VS-48.) 3. Secure door on lower pulley housing so it will fit tightly, by providing additional door latches. Close openings in lower pulley housing to prevent air leaks. This will increase velocity at blade opening in saw table. 4. Provide a brush or wiper on lower pulley and on blade in lower housing to continuously remove "marinite" adhering to these parts. ARCH 19190 January 24, 1962 -3- Dept, of Public Health 5. If large pieces of "marinite" are cut out of doors, the operator should be provided with a respirator approved for use against toxic dust (MSA Dustfoe or equal). The operation should be conducted so that all dust produced will be blown away from windows, doors and air intakes, so that other workers will not be exposed. 6. When making changes or when installing new exhaust systems, it is recommended that the principles of good duct design as advocated by the American Conference of Governmental Industrial Hygienists be followed. (See attached drawings, figures 6-6 through 6-9.) In closing, we wish to thank you for the courteous cooperation and assistance given to this department during our study. If you should have any questions concerning this report, please do not hesitate to call upon us for any assistance we may be able to offer. Very truly yours C. E. Neroethi, M.D. ifealth Officer LSH: r Dep. Dir. of Sanitation ARCH 19191 i i < i i ! $ t j Bkxte zadrft, j shiK7f wiv7. CM ! ino'H-J ! *e j avr 2 xj J i <#9r Jl to 4 | ar 4 $o 6 J &sr 6 to 8 j f&Uctr. i Toe j \: T-* *' 1\ 35-J i 550 1 550 ; : 550 1 BOO i i 550 | MX? ; 1 -W } !C , Tofts ?\b? soo. '::yj ;&$ !>X> Due! vt&chy j 4000fpV. &try Jess tkr VFpist icxvs'-i&a. \ t % * la ii i4 A/n/*:'"*** *J<ZX t^VL. ;t?iV < i * i \ t ^4.'Y/; s*w i ARCH 19192 Poor ELBOW RADIUS E3bc*9 tPxdd1 2 or E1/2 dfamsfon csntorfot rodka except teto* space ddHnedponod. ---w-- tr Good 1 A > -1L / | - Il l________r J-->.--i--L Bod ASPECT RATK) r&tp AR()hi&*uf3yr9Ciori3Jkxek>c* w . bm%& ;m: ; ; fw-v; - '.-,>-ww>;: *7 !^s ` :: *.!> -- * '*<** 't ,'f "J* V-'i ,-r; r'l . ._??i A`A,*-\*e>% i ' 3- Bod Hn'tstxsmi *m*nr/w*e$'. A Grot* tectiem arj*. PROPER DUCT SIZE StoetotMtohe&totalGS&itOBaprt ve'^Jty oridgher. amsbcan ccNmexa or eaVCSHMSKTAL mOUSTOAl HTSSW5T2 iBw, #S2f PRINCIPLES OF DUCT DESIGN CATlt /-55 I "'W^ !& 6-6 '^rzes'*rr~i ^CH 19793 *y. / tK/i cAo/y* *> CSam*(r Good n 3 Bod Ai__i Branches should enter at gadua!expansions and of on angle of 3G or fsss (preferred) to 45 ifnecessary. fair BRANCH ENTRY Bad Branches sf.ooid no) enter direcity qppoji^ coch other. 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