Document V3vK2wXLJakaR0JwgYBkzkkJZ

/ V"1 Johns-Manvill Corporation Gitinwood PUi Oer>*r. Color ado 80217 Health.Slty & Envlroamanl Dapartmaat August 8, 1975 Mf.e %-y-TT e I S T 0 0 0 I135 Hr- Peter Doty Building A-24 Dow Chemical Co. Midland, Michigan 48620- ; . : - > .. .. Dear Mr. Doty: *' * J. V. Magee has asked me to reply to" your telephone inquiry concerning TRANSITE and asbestos fiber. Products such as TRANSITE sheet or pipe presently cannot be made without asbestos fiber. Experiments have been made using fiber gla^s as a substitute for asbestos. Fiber glass, however, is not alkali resistant and is attacked by the cement with a. subsequent loss in product strength, Routine handling and installation of asbestos-cement sheets normally will not generate airborne fibers approaching the limits established by the OSHA asbestos standards. Fabrication of the sheet by power sawing utilizing either fixed or portable, saws can generate fiber concentrations above the allowable. However, this exposure can readily be controlled by the installation of mechanical exhaust ventilation equipment on the fabricating machinery. The Asbestos Information Association/NA is preparing a series of recommended work practice brochures for asbestos-containing products. One of these is entitled, "Recommended Work Practices - Shop and Field Fabrication of Asbestos Sheet Products". For your information I enclose a draft of this brochure. I must emphasize that this is only a draft and may contain some minor typographical or other errors but the basic information is correct. If after reading the enclosure you still have questions concerning the handling of TRANSITE products, please contact me in Denver. Verv trulv vours . Fdmund M. Fenner, Director Technical Affairs tfc/r 8 - ST000I136 ASBESTOS INFORMATION ASSOCIATION 1&6O L Suett. N W. / Wasivrig'on. D C ?0036 / (202) 223-4335 . RECOMMENDED WORK PRACTICES SHOP AND FIELD FABRICATION OF ' ASBESTOS SHEET PRODUCTS DRAFT 17377s Revised 5/1/75 Z/Z/15. V/ . INDEX INTRODUCTION................................................................................................... t lt * SUMMARY OF OSHA ASBESTOS STANDARD. . - ... - Page 1 - Pages 3 GENERAL RECOMMENDATIONS ' * . > ' - - - * Pages 6 SPECIFIC RECOMMENDATIONS COMMENTS ....................... Page 8 SHOP (FIXED) TOOLS ......................Page 9 Radial Arm Saw . . ... .. . ... . . '. ;. . . . . Page 10 Table Saw . . ......................... Page 11 Stone Saw ..................................................................... Page Shaper ............................... ^ . Page 13 Vacuum Requirements................ Page 14 PORTABLE TOOLS................................ .................................... Page 15 Rotary Power Saw................. ............. Pages 16-2 Electric Drill ................................................................ Pages25- Electric Sanders ..................................................................... Pages31- Vacuum Requirements ......................... ..... Page 35 PORTABLE VACUUM SOURCE ..... .......................... Pages 36- APPENDIX A - OSHA ASBESTOS STANDARD (1910.93a) APPENDIX E - VACUUM CLEANING STATIONS SKETCH <y> O S 7ST000 I 13.8 _ INTRODUCTION The Occupational . < L'cfcy and HealthActwas signed into lav; on December 29, V*V0 and became effective', pn April'28,1971. The Act has the Mn.tcd objective.of assuring Ameri.can wofJeer a safe and healthy workplace.' > On December 7, 1971 t'ne Secretary .of Labor issued,n emergencytc-iiiporary / standard for exposure to asbestos'dust J.' As required by the Act, a permanent standard for asbestos exposure vras pro mulgated six month:;, later on June It 1972.- The p'refent OSHA ' Asbestos Standard, discussed in`this booklet,became effective on -July . 7, 1972. The work practices on the following pages have been.prepared by the Standard:; and Technical Committed of the Asbestos In formation Asnoci.. l:'.on/North America. They are intended as general guidance \or safe and clean workplace conditions in keeping with the spirit and intent of the OSHA Standard for Occupational Exposure to Asbestos Dust. ' These practices have been developed through careful study and consultation and are recommended as good procedure.'. It is recognized that manufacturing conditions vary. .Implementation of the practices contained herein cannot be considered as a guarantee of OSKA compliance. Where there may be a question of compliance, OSHA personnel should be consulted. Thorough underst.-:.-.cling of the OSKA Asbestos fltundurd is im portant to manor;.:-..icnt of any company utilizing asbestos in its rr...nufacturing o : processing operations. Revisions or anendrits to the st.'uula rd which may occur will be published as c. matter of cournin the Federal Register. This publication v.-ill be revised, . necessary, to reflect changes that may occur. r o- 2- t 1 ;.' * rT PRODUCTS AND 09i:i:sV.-,.0H3 ' v Types of asbestos sheet product's covered by those work'-- practices are: _ Flat asbestos-cement sheets - plain ^nd pig--. ' wanted - press. produced ' *; ` *. * Corrugated asbestos-cement sheets - preiss` produced Flat asbestos-cement sheets - plain and pigmented-- wet machine p* roduced . ' f Corrugated .lobestos cement sheets - wet machine? pro duced . ' \' ' Asbestos-c -M.t-nt sheets and shapes - extruded ;' Flat asbestos calcium silicate sheets - i-iress prpduced .--Structural sandwich panels - flat asbestos-cement' sheets with insulating core. Opt--r.itions to v/hU.b these work practices may ' apply ore: \ Handling a..*i w. re housing . General _-!;eeping, including waste di f-porui Drilling r Shaping . i Sawing Sanding ' STOOOI 139 r~ K. 3 0*i I I 0001S LUKMARY of THE REC-UIaEMEHTS of THE OSHA ASBESTOS STANDARD (1910.9 2a)____________________ ;__________________ . ; > *k:;ic ral Co.rijiin Ls ,. After extensive public hearings, OSHA published a "Standard for Exposure to Asbestos Dust" in the Federal Register, Volume 37, ;:o*. 110 dated Wednesday, June 7, 19.72.t A copy of the complete standard is included at the back of this booklet. It appliesto any manufacturing, fabricating or handling process or operation utilizing asbestos fiber or materials containing asbestos ii r Ti.e standard is divided into eight major categories: 1 9 10.93a (b) Exposure Levels hots the maximum allowable asbestos fiber concentration ^ in Lhe workplace air. 1910.93a(c) Methods of Compliance it.-commends procedures to meet the exposure levels. . 1910.93aJd) Porsor.ai Protective Equipment :-l-oci fies types of personal protective equipment and c.fines the circumstances under which they are required. vIC.93a(e) Method of Measurement 11 u~."y~3aTf7 7iO)7I'Eo~fTny Specifics the monitoring procedures to be used to determine if your workplaces meet the allowable exposure levels. h. 1 9.10.93a (g) Caution Siyns and Labels Si.i; ec when caution signs and labels are required, and the wording to bo used. ,. 1910.93a (n) Housekeeping > Specifies resu; . to he obtained from housekeeping and the thods of wasco disposal. 4 t t STOOO.I 141 7. 1910.93a(i) Recordkeeping '5 Sets typo anc! duration of monitoring recordkeeping. Sets requirements for employee notification\of monitoring results. / a. 1910.93a<j) .Medical Examinations; .* Details the requirements for. medical 'examinations. Soecific Comments 1 Exposure Levels [1510.95a(b)J v .. It is the employer's responsibility to assure that exposure . of employees to airborne concentrations'* of asbestos fibers does not exceed the levels prescribed by the Standard. The* OSi.A asbestos standard maximum'permissible levels of asbestos fiber in the workplace air ^are: a. Eight hour time weighted*average: (1) At present: 5 fibers per cubic centimeter. (2) Effective July 1, 1976: 2 fibers per cubic centimeter. b. Ceiling concentration: (1) At present: 10 fibers per cubic centimeter. (2) Effective July i, 1976: (no change). it: both cases, the standard refers to fibers longer thar. ; i c :cn.e ters . .'bihods of Compliance [1910.93a (c)] j i r;ec;r incj Methods Engineering controls such as isolation, enclosure, exhaust ventilation and dust collection shall be used to meet the g j.x-scribed exposure levels. All hand operated ana power operated tools which may produce <ii: borne, .ashes to;. fibers in excess of permissible exposure levels shall be provided with local exhaust systems. 5 STOOOI142 Wet Methods .. When practicable, asbestos products shall be handled in a vet state sufficient to prevent;the emission of dust to the atmosphere. This procedure is not required where the usefulness of the product might be diminished be wetting. The applicability of wet methods is limited. In most situations, engineering controls as noted above are more applicable. ' * Personal Protective' Equipment and .Clothing [1910.93a(d)] Respiratory Protection Respiratory protection is required whenever the airborne concentrations of asbestos fiber .exceed either the permissible time weighted average level or permissible ceiling concentration. The type of respirator to be used is determined by the fiber concentration in the workplace. a. Fiber concentrations up to, but not exceeding 10 times the allowable limit; Air purifying respirator - reuseafcle or single use. b. Fiber concentrations up to, but not exceeding 100 times the allowable limit: Powered air purifying respirator. c. Fiber concentrations exceeding 100 times the;allowable lii.iit: ' Type "C" supplied air respirator. luolvctivo ClothLnc . Whenever the airborne fiber concentrations exceed the ;i escribed ceiling level the employer shall provide end require the use of special clothing, such as coveralls or similar whole body clothing, head coverings, gloves, and coot coverings Whenever the airborne-fiber concentrations exceed either the permissible time weight average concentration or permissible ceiling concentr tion the employer shall provide change rooms for his employees. The change rooms shall be equipped with two separate lockers or containers,for each employee so separated or isolated as to prevent contamination of the employee's r.trc-et clothes from his work clothes. 5a t M' S T 0 0 0 I143 Methods of Measurc.v.cat [1910.93a(c}'] .Monitoring f 1'910.95a All monitoring shall be done by the ifiembrane filter method at 400-500 x-(magnification). (4 millimeter objective) with phase contrast illumination. '. , :. \ The standard requires that within .six months of its effective date, all workplaces where asbestos fibers are released shall be monitored to determine exposure levels. Monitoring must be repeated at six month intervals if the fiber concentrations are above permissible levels. If fiber concentrations are - below permissible levels, monitoring should be repeated at reasonable intervals at the employer's discretion. * Affected employees or their representatives shall' be given a reasonable opportunity to observe any required monitoring and"shall have access to the monitoring records. Any employee found to have been exposed at any time to airborne concentrations of asbestos fibers ir. excess of the prescribed limits shall be notified in writing of the exposure as soon as practicable but not later than 'five days of the finding. Caution Signs and Labels (1910.93a(g)] Caution signs shall be displayed at each workplace where asbestos fiber concentrations exceed permissible exposure 1 o ve 1 s. Caution labels shall be applied to all materials and products v.iiich during any reasonably foreseeable use might release concentrations of asbestos fibers in excess of permissible exposure levels. Housekeeping f19i0.93a(h)] All external surfaces, machinery and equipment shall be wjinterned free of asbestos fiber accumulations that might, it dispersed, create asbestos fiber concentrations above permissible exposure levels. For recommendations on proper housekeeping procedures, see the "llousckoepi ng" section under general recommendations. I 7. Recordkeeping 11 91 0.93a(i) ] r Every employe;: shall maintain records of any personal } or environmental monitoring required by the standard. Records shall be maintained for a period ?f jatt least three years. ' , .. . . . , ; . , , f 8. Medical Examinations [1910.93a(j) ] . ' / . *"'** . * Freplr.cerr.ent, annual, and termination medical examinations must be provided or made available by the employer for any employee "...engaged in occupations exposed to airborne, concentrations of asbestos fibers." These medical records must be kept for 20 years ana are available to the employee's physician. This section has proved to be one of the most confusing in the regulations since it does not define any cutoff level below which examinations are not required. It is anticipated that t.he revised regulations will provide a more specific ( definition such as that originally proposed by NIOSH in the Criteria Document: .` "For purposes of this requirement the term 'exposed to asbestos' will be interpreted as referring to tine-weighteu average exposures above 1 fiber/cc or peak exposures above 5 fibers/cc." I I0001S J, +.*J. .c : S T000I145 c;i:.\eral .'il-commej:dations ::hcjust and Dust Collection Systems 'he OSHA Asbestos Standard requires that exhaust and dust . , 1 collection systems bo designed and maintained in accordance with American National Standard*, "Fundamentals Governing . the Design and Operation of Local Exhaust Systems"ANSI . Z9.2-1971. Another authoritative reference is: Industrial Ventilation, A Manual of Recommended Practice Prepared by: Committee on Industrial Ventilation American Conference of Governmental Industrial . Hygienists ` . i' P. O. Box 453 Lansing, Michigan 48902 >?he U. S. Environmental Protection Agency requires that the ( air cleaning device used with asbestos fiber dust collection ystoms be a fabric filter collector. When the use of fabric filters creates a fire or explosion hazard, the Administrator of the Agency may authorize the use of a high energyvet collector. For small and intermittent production and fabrication operations major dust collection systems of the high volume, low velocity type design described in the references above may not be necessary. Instead, systems of the low volume, high velocity type utilizing as their exhaust air source a high efficiency vacuum cleaner .^uld be suitable. For design information on these systems : for to the "AIA/KA Recommended Work Practices on Fabrication ::f Asbestos-Containing Sheet Products"- which may be obtained on .vjiiuest to the AIA/.'lA. t! 1 exhaust and dust collection systems should be inspected riodically for proper functioning. For continuous operations rt is recommended that the system operation and the interior of the baghouse be checked daily. A scheduled maintenance program that includes bag replacement should be prepared and followed. ^.American National standards Institute : 14 30 Broadway Few York, NY 1001U i 6a ; S T0001146 wherever possible, operations involving asbestos-icontaining materials should be isolated from, other work areas by partitions, curtains or other means. If central-exhaust.systems are utilized the work areas should be maintained under a slight negative pressure. Housekeeping ", : *. . v 4% .. * Housekeeping is an essential part of any manufacturing operation. It is oven more essential in an asbest^oS^using plant because airborne dust created by lack of housekeeping has the potential for harm to your employee. `" . The OSHA asbestos standard stipulates that "all external surfaces in any place of employment shall be maintained free of accumulations of asbestos fiber if, with their dispersion, there would be an .. ..oscc-csivt concentration". It is recommended that surface cleaning be done by vacuum. Portable vacuum cleaning units should be equipped with internal filtration and disposable dust bags. Single or multi-hose stationary vacuum cleaning systems designed for use with . . bestos containing duss are available from at least two manufacturers. Vacuum cleaning stations can be added to existing dust collection systems as- shown on sketch 1 in tiic appendix. If circumstances require floor sv.*eeping: with brooms, then the loose material being swept should be treated with water or other curt suppressant. `.v.c* OSHA standard iu]uirc.-s thst asbestos waste which-when' Handled or transported could generate airborne fibers,in excess T the al leviable exposure limits, be disposed of. in sealed bass or-closed containers. 7 PERSONAL ItVGIt:,;.: In the use of a*:'-.:>i.os for the processing of .asbestos-containing products unlc*;J v-'d p/ocedures are followed dust' donditions can result. Employ^.v:uct be aware that excessive inhalation of asbestos dust i.v* injurious to health** /Every e'ffqrt should be made to el uvi ::ite dust conditions and avoid unnecessary ex posure to dust. - - ` * * * * , , Good personal hygiene practices are important-in"every working situation. When working with -asbestos, .workers are urged to ' observe the following personal hygiene, practices 'for their own health protection, their families and those with whom they : work: *- . < ' .. S .1 . Avoid ci.jv^'ette smoking - * '. ' . VJash rl: -ouijhly before eating-. . Shower after work * .' . ' ' - . Wear proper protective clothing including head covering when the situation warrants .- i % Change: to work clothes upon arrival at work and change from \;oj;x clothes at conclusion of work . If work clothing is taken home, carry in a bag and v;ash so: .t;\-;tely fi*om other clothing, (/ever shake dusty clothj.iV.;. Use a v/ashing machine. . Use ro. -'i racers when required'. Be sure that respirators fir pro...'.fly. It makes good c to have a dust free workplace. It is important to the health ). involved. Dust conditions can.be controlled by the simple application cf good practices c.nd common sense in the workplana. STOflOl147 . -8 RECOMMENDED WORK PRACTICES SHOP AND FIELD FABRICATION OF ASBESTOS SHEET PRODUCTS ) r STOOOI I 48 SPECIFIC RECOMMENDATIONS - COMMENTS Prior to handling of sheet materials excess dust should be removed from the surface of the sheets to prevent dispersion of asbestos fiber into the workplace. Fabricating machinery should be equipped with suitable dust control systems. Refer to standards on page 8 and to typical designs shown on pages 10 through 37. All dust control systems which discharge exhaust air to atmosphere must be equipped with fabric filter collection devices (requirement of the Federal Environmental ProtectionAgency "National Emission Standards for Hazardous Air Pollutants Asbestos"). VJet fabricating methods can be a suitable alternative to dust control systems utilizing exhaust ventilation. After fabricating and before shipping all excess dust and chips should be removed from the surface of the sheet to prevent dust contamination of the fabricator's workplace and his customer's workplace. ' All dust and waste must be disposed of in accordance with paragraph "Housekeeping" on Page 5. Dust from the dust collection devices must be disposed of in sealed containers. Scrap disposal, since it is not friable and disposal does not generate asbestos fiber concentrations above permissible levels, need not follow the requirement for sealed and labeled containers. 9 SHOP (FIXED) TOOLS t e > . STOOOI149 ( K: -10- RAD1AL ARM SAW: < J. Dust escapes from top side of material as saw .breaks through top surface - some goes to saw post area, some goes around top guard and out towards operator. * 2. Dust escapes from bottom surface as saw breaks through and goes below table top. Recommended engineered dust control system. STOOO-I I 50 AIR VOL'JiV.c = 2500 C. F. TOTAL 5UCTI0.V - l V*WATER OR !*` Hg ii- TABLE SAW ` ST000I151 of material engages downward moving saw teeth. Dust is propelled downward and towards back of saw below table top. '' 2'. Some dust generated over top of material cut- due to rubbing of saw or binding'in saw cut. Dust rises over saw and towards operator. Recommended engineered dust control system. 12- `STONE SAW: - DRY CUTTING: i.. Stone saws when used dry cutting Asbestos sheet products generate dust.as follows: r . 1* -- 1. On the leading edge of . the wheel as it breaks '' '-..* < *; through the top surface. ...... 2. On the back edge of the* hgod which entity .dust ' \ ' ' '' * ' r. ' ' and chips carried over, : '* ... 'saw directions ;.- : EXISTING HOOD- :,r :*.1 . .* \ . . 1.1 n 1. ... 1, .' v-l Recommended engineered dust control system. 1. Add rubber skirt on existing hood to.ij inch above work. 2. Add 6" pipe to existing hood for dust pick-up. 3. Add 8" wide slot belcw table for dust pick-up. 4. Use 2500 to 4000 C.F.M. at 14" water on 1" Hg. for vacuum pick-up. I ST0001152 EXISTING HOOD- 6mD!A.- ADO RUBBER EXISTING 1/2 SKIRTS- WIDE SLOT1 l/2"CLEAR ABOVE WORkX / / TN I]jm - I CLEANOUT~K:l_ __ - srlr - ^ - A ~ ~ 8"0IA. SHAPER - FOR DRY SHAPING: A shaper when shaping or contouring an asbestos. fv sheet product generates dust.as follows: 1. The cutter blade on the shaper' peels off a very fine chip due to the high velocity of * * the shaper. . ESI I.0001S i Recommended engineered dust control systems and equipment. 1. Enclose shaper shaft and tool in metal housing. - 2. Add rubber skirt on 4 sides to 1" clear above work. \ 3. Add duct work as shown on sketch. Vacuum required is 2500 C.F.M. at 14" water or 1" HG. 4. Use 2" outlet and hose to canister type vacuum 75 C.F.M. at 6B" water for 5" Hg. 14- ENGINEERED ,i - DUST i CONTROL TOOLS-SHOP n ' ' TOOLTS . VACUUM REQUIREMENTS TYPE TOOL RADIAL ARM SAW TABLE SAW C.F;H. - ,/ . * l . : *2500 !asop-:i VACUUM . ( *. 14" Water i;14" Water STONE SAW ?00 to 4000 -.14? Water SHAPER 2500; 14" Water STOOO.I 5I U 15 PORTABLE TOOLS STaOOl155 I METHODS CF ENGINEERED DUST CONTROL SYSTEMS ' * .' PORTABLE ELECTRIC ROTARY POWER SAWS. .1 . * . . ' I.' Use dust control systems shown below. (Spec. A-l) or a Cape Asbestos shroud kit. (Spec. A-2) II.. Do all cutting on J-M design vacuum box (6) as per Spec.. No. E-l,` or cut into 1/2" plywood. ~; ,(3>-ASSEST0S SHEET PRODUCT . STQOOI156 -DUST FROM TOP SURFACE BLADE GUARD 2)-'MASONRY WHEEL S'800 TO 5800 R.RM. = = "iS7 (6) VACUUM BOX K5>-0UST FROM BOTTOM SURFACE CUT OR ALTERNATE CUT INTO 1/2*'PLYWOOD SHEET V rTHIS on THIS r LENGTH TO SUIT 10 Ft. TO 20 Ft. CAPE ASBESTOS SAW SHROUD y: ~ SPEC. A-2 yAcuy;.i_u^Jii aLOW VOLUME "hic.h VELOCITY SPEC. SERIES G ; STOOOI 157 detail-i : -18- SHfcC. A-l. DETAIL 2 / V 8S-I I0001S C; % UcTAlL A \ GO O O o err UD 1 1 ^ -- r-w. /V-- -l . *# . A o t r-- r% m _ "7 J tA * r"M A PM A nr I * -21- ST000116 1 specification'no. A-2 DETAIL'1 *. ' * ' ' * MANUFACTURER: '* Cape Universal Building Products ' Uxbridge, Middlesex England or (Watford 34551) Register Office Box 165, Exchange Road, Waterford 34551. TYPE OF EQUIPMENT: Plastisol Type Semi-Flexible Portable Saw Special Design Shroud Kit 7" for. 7%w Sawcats .* ... ; ' . 9k" for 9kH Sawcats * Stocked in Denver by H. L. Foss, Black & Decker distributor. EQUIPMENT SPECIFICATIONS: . Order through Cape Universal (includes following) 1. Shroud ' ' 2. Hose harness, comprising2 hose pieces and "Y" 3. Jubilee clips (2) ' . SJZES: For Ik" and 9k" Sawcats ELECTRICAL: -NONE- VACUUM: 2 hose pieces for vacuum attachments SPEC. A-2 DETAIL 2 aproved by chs Asbescosis Resesrch Council 0STQp 1162 The saw shroud has been tailored to fit the Black 3nd D=c5t?' ?' portable circular saw and used in conjunction witn approve industrial dust extraction units. A list of such units is induces in the ASBESTOSIS RESEARCH COUNC.l Control arc Guide No! 5. In addition to its use with Asbestos tasec rrv.v; the saw shroud is also suitable (or a wide variety of other materials. ' Operating instructions The material to be sawn should be placed on a wooden base Iprelcrably V plywood ii considerable cutting is to be co'sspanning the whole length of the sow cut and ;r.c b^ce c:c:-. adjusted so tifat it cuts ;tvour;h the material wun minimum. Cut into bt.se bo.v d. Vlus nevents dust Irom tailing below :*; saw cm and conccnti.nex the extraction to tne iivoud one - ; . DETAIL 3 r> mponents ustratcd overleaf) srruntling sew uussctvibly with rood 1 Shroud * ' * i* 2 Hose harness, comprisin9 two hoss pieces end `Y* connector # 3 Jubilee clips (4 of No 1 and 1 of No 2} Remove bolt 4, outer clamp washer 5, saw blade 6. inner clamp washer, wire nut 7. boll 3, guard stop 9. wing nut 10. shoe 11. two retaining screws 12. lever arrn 13. screws 14 15 15 17 and finally main guard 18 by ci.'eruiy lapping free with hide faced hammer. Should motor unit eiso be v.-itnirawr:. ensure carbon brushes are correctly re-positioned before rcassomciy Fit saw shroud 1 to guard 18 and reassemble in reverse order ensuring :ha: sll screws arc fully tightened. Omit iGver arm 13 and retaining `.trows* 12. , Where necessary lilt shroud to ram access so screws. To tighten screw 15 insert screwdriver as shown in drawing O.Ensure that shroud is fitted ir:>ce lip of shoe when replacing saw btane. Connect hose Harness to shroud. Connect hoses to Y piece, secure ail connections with Jubilee elms. An additional dip is included for coupling the unit to the dust extraction hose. '1~* ,i f. r A A A *"\ -.11 Dr*r Aw l--* tr. rr r-, o cr / r-* -24BLOCKS AS REQUIRED TO *19110001S- METHODS OF ENGINEERED DUST CONTROL SYSTEMS . PORTA8LE ELECTRIC DRILLS NORMAL DRILLING OF HORIZONTAL SHEETS DRILLING OVERHEAD OR DRILLING OF VERTICAL SURFACES . STOOOl|65 NO DUST PROBLEM (IF DESIRED BRUSH CN WATER TO WET SURFACE LIKE MACHINIST LUB RICATES DRILLS) . Y--" OR l'/2 HOSE SPEC. B-l CAPE PORTABLE DRILL NOZZLE KIT DUST EXTRACTOR-DRILL